HHH-18447 Try using native cast for string to boolean

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/AltibaseDialect.java

@@ -393,20 +393,26 @@ public class AltibaseDialect extends Dialect {
 				}
 				break;
 			case INTEGER_BOOLEAN:
-				result = BooleanDecoder.toIntegerBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "1", "0" )
+						: BooleanDecoder.toIntegerBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
 				break;
 			case YN_BOOLEAN:
-				result = BooleanDecoder.toYesNoBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "'Y'", "'N'" )
+						: BooleanDecoder.toYesNoBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
 				break;
 			case BOOLEAN:
 			case TF_BOOLEAN:
-				result = BooleanDecoder.toTrueFalseBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "'T'", "'F'" )
+						: BooleanDecoder.toTrueFalseBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
@@ -702,4 +708,14 @@ public class AltibaseDialect extends Dialect {
 		};
 	}
 
+	@Override
+	public String getDual() {
+		return "dual";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return " from " + getDual();
+	}
+
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/AltibaseSqlAstTranslator.java

@@ -218,16 +218,6 @@ public class AltibaseSqlAstTranslator<T extends JdbcOperation> extends AbstractS
 		emulateQueryPartTableReferenceColumnAliasing( tableReference );
 	}
 
-	@Override
-	protected String getDual() {
-		return "dual";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return " from " + getDual();
-	}
-
 	@Override
 	protected boolean needsRecursiveKeywordInWithClause() {
 		return false;

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/CUBRIDDialect.java

@@ -515,4 +515,16 @@ public class CUBRIDDialect extends Dialect {
 		sqlAppender.append( diffUnit.conversionFactor( toUnit, this ) );
 	}
 
+	@Override
+	public String getDual() {
+		//TODO: is this really needed?
+		//TODO: would "from table({0})" be better?
+		return "db_root";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return " from " + getDual();
+	}
+
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/CUBRIDSqlAstTranslator.java

@@ -77,16 +77,4 @@ public class CUBRIDSqlAstTranslator<T extends JdbcOperation> extends AbstractSql
 	protected boolean supportsRowValueConstructorSyntaxInQuantifiedPredicates() {
 		return false;
 	}
-
-	@Override
-	protected String getDual() {
-		//TODO: is this really needed?
-		//TODO: would "from table({0})" be better?
-		return "db_root";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return " from " + getDual();
-	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/DB2LegacyDialect.java

@@ -68,6 +68,7 @@ import org.hibernate.metamodel.mapping.EntityMappingType;
 import org.hibernate.metamodel.spi.RuntimeModelCreationContext;
 import org.hibernate.procedure.internal.DB2CallableStatementSupport;
 import org.hibernate.procedure.spi.CallableStatementSupport;
+import org.hibernate.query.sqm.CastType;
 import org.hibernate.query.sqm.IntervalType;
 import org.hibernate.query.sqm.TemporalUnit;
 import org.hibernate.query.sqm.mutation.internal.cte.CteInsertStrategy;
@@ -1134,6 +1135,16 @@ public class DB2LegacyDialect extends Dialect {
 		return super.extractPattern( unit );
 	}
 
+	@Override
+	public String castPattern(CastType from, CastType to) {
+		if ( from == CastType.STRING && to == CastType.BOOLEAN ) {
+			return "cast(?1 as ?2)";
+		}
+		else {
+			return super.castPattern( from, to );
+		}
+	}
+
 	@Override
 	public int getInExpressionCountLimit() {
 		return BIND_PARAMETERS_NUMBER_LIMIT;
@@ -1201,4 +1212,14 @@ public class DB2LegacyDialect extends Dialect {
 	public boolean supportsFromClauseInUpdate() {
 		return getDB2Version().isSameOrAfter( 11 );
 	}
+
+	@Override
+	public String getDual() {
+		return "sysibm.dual";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return " from " + getDual();
+	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/DB2LegacySqlAstTranslator.java

@@ -604,16 +604,6 @@ public class DB2LegacySqlAstTranslator<T extends JdbcOperation> extends Abstract
 		return false;
 	}
 
-	@Override
-	protected String getDual() {
-		return "sysibm.dual";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return " from " + getDual();
-	}
-
 	@Override
 	protected void visitReturningColumns(List<ColumnReference> returningColumns) {
 		// For DB2 we use #renderReturningClause to render a wrapper around the DML statement

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/DerbyDialect.java

@@ -1040,6 +1040,11 @@ public class DerbyDialect extends Dialect {
 		return true;
 	}
 
+	@Override
+	public boolean supportsValuesList() {
+		return true;
+	}
+
 	@Override
 	public IdentifierHelper buildIdentifierHelper(IdentifierHelperBuilder builder, DatabaseMetaData dbMetaData)
 			throws SQLException {
@@ -1057,4 +1062,14 @@ public class DerbyDialect extends Dialect {
 		return DmlTargetColumnQualifierSupport.TABLE_ALIAS;
 	}
 
+	@Override
+	public String getDual() {
+		return "(values 0)";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return " from " + getDual() + " dual";
+	}
+
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/DerbyLegacyDialect.java

@@ -1051,6 +1051,11 @@ public class DerbyLegacyDialect extends Dialect {
 		return getVersion().isSameOrAfter( 10, 4 );
 	}
 
+	@Override
+	public boolean supportsValuesList() {
+		return true;
+	}
+
 	@Override
 	public IdentifierHelper buildIdentifierHelper(IdentifierHelperBuilder builder, DatabaseMetaData dbMetaData)
 			throws SQLException {
@@ -1062,4 +1067,14 @@ public class DerbyLegacyDialect extends Dialect {
 	public DmlTargetColumnQualifierSupport getDmlTargetColumnQualifierSupport() {
 		return DmlTargetColumnQualifierSupport.TABLE_ALIAS;
 	}
+
+	@Override
+	public String getDual() {
+		return "(values 0)";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return " from " + getDual() + " dual";
+	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/DerbyLegacySqlAstTranslator.java

@@ -298,16 +298,6 @@ public class DerbyLegacySqlAstTranslator<T extends JdbcOperation> extends Abstra
 		return false;
 	}
 
-	@Override
-	protected String getDual() {
-		return "(values 0)";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return " from " + getDual() + " dual";
-	}
-
 	@Override
 	protected boolean needsRowsToSkip() {
 		return !supportsOffsetFetchClause();

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/DerbySqlAstTranslator.java

@@ -298,16 +298,6 @@ public class DerbySqlAstTranslator<T extends JdbcOperation> extends AbstractSqlA
 		return false;
 	}
 
-	@Override
-	protected String getDual() {
-		return "(values 0)";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return " from " + getDual() + " dual";
-	}
-
 	@Override
 	protected boolean needsRowsToSkip() {
 		return !supportsOffsetFetchClause();

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/FirebirdDialect.java

@@ -401,25 +401,33 @@ public class FirebirdDialect extends Dialect {
 				}
 				break;
 			case BOOLEAN:
-				result = BooleanDecoder.toBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "true", "false" )
+						: BooleanDecoder.toBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
 				break;
 			case INTEGER_BOOLEAN:
-				result = BooleanDecoder.toIntegerBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "1", "0" )
+						: BooleanDecoder.toIntegerBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
 				break;
 			case YN_BOOLEAN:
-				result = BooleanDecoder.toYesNoBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "'Y'", "'N'" )
+						: BooleanDecoder.toYesNoBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
 				break;
 			case TF_BOOLEAN:
-				result = BooleanDecoder.toTrueFalseBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "'T'", "'F'" )
+						: BooleanDecoder.toTrueFalseBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
@@ -1094,4 +1102,14 @@ public class FirebirdDialect extends Dialect {
 		}
 
 	}
+
+	@Override
+	public String getDual() {
+		return "rdb$database";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return " from " + getDual();
+	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/FirebirdSqlAstTranslator.java

@@ -260,16 +260,6 @@ public class FirebirdSqlAstTranslator<T extends JdbcOperation> extends AbstractS
 		return false;
 	}
 
-	@Override
-	protected String getDual() {
-		return "rdb$database";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return " from " + getDual();
-	}
-
 	private boolean supportsOffsetFetchClause() {
 		return getDialect().getVersion().isSameOrAfter( 3 );
 	}

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/H2LegacyDialect.java

@@ -47,6 +47,7 @@ import org.hibernate.internal.util.JdbcExceptionHelper;
 import org.hibernate.internal.util.StringHelper;
 import org.hibernate.metamodel.mapping.EntityMappingType;
 import org.hibernate.metamodel.spi.RuntimeModelCreationContext;
+import org.hibernate.query.sqm.CastType;
 import org.hibernate.query.sqm.FetchClauseType;
 import org.hibernate.query.sqm.IntervalType;
 import org.hibernate.dialect.NullOrdering;
@@ -513,6 +514,16 @@ public class H2LegacyDialect extends Dialect {
 				: super.extractPattern(unit);
 	}
 
+	@Override
+	public String castPattern(CastType from, CastType to) {
+		if ( from == CastType.STRING && to == CastType.BOOLEAN ) {
+			return "cast(?1 as ?2)";
+		}
+		else {
+			return super.castPattern( from, to );
+		}
+	}
+
 	@Override
 	public String timestampaddPattern(TemporalUnit unit, TemporalType temporalType, IntervalType intervalType) {
 		if ( intervalType != null ) {
@@ -991,4 +1002,14 @@ public class H2LegacyDialect extends Dialect {
 	public boolean supportsCaseInsensitiveLike() {
 		return getVersion().isSameOrAfter( 1, 4, 194 );
 	}
+
+	@Override
+	public boolean supportsValuesList() {
+		return true;
+	}
+
+	@Override
+	public String getDual() {
+		return "dual";
+	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/H2LegacySqlAstTranslator.java

@@ -386,11 +386,6 @@ public class H2LegacySqlAstTranslator<T extends JdbcOperation> extends AbstractS
 		return getClauseStack().getCurrent() != Clause.WITHIN_GROUP || getDialect().getVersion().isSameOrAfter( 2 );
 	}
 
-	@Override
-	protected String getDual() {
-		return "dual";
-	}
-
 	private boolean supportsOffsetFetchClause() {
 		return getDialect().getVersion().isSameOrAfter( 1, 4, 195 );
 	}

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/HSQLLegacyDialect.java

@@ -315,25 +315,33 @@ public class HSQLLegacyDialect extends Dialect {
 				}
 				break;
 			case BOOLEAN:
-				result = BooleanDecoder.toBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "true", "false" )
+						: BooleanDecoder.toBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
 				break;
 			case INTEGER_BOOLEAN:
-				result = BooleanDecoder.toIntegerBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "1", "0" )
+						: BooleanDecoder.toIntegerBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
 				break;
 			case YN_BOOLEAN:
-				result = BooleanDecoder.toYesNoBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "'Y'", "'N'" )
+						: BooleanDecoder.toYesNoBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
 				break;
 			case TF_BOOLEAN:
-				result = BooleanDecoder.toTrueFalseBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "'T'", "'F'" )
+						: BooleanDecoder.toTrueFalseBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
@@ -825,6 +833,11 @@ public class HSQLLegacyDialect extends Dialect {
 		return true;
 	}
 
+	@Override
+	public boolean supportsValuesList() {
+		return true;
+	}
+
 	@Override
 	public IdentityColumnSupport getIdentityColumnSupport() {
 		return identityColumnSupport;
@@ -900,4 +913,9 @@ public class HSQLLegacyDialect extends Dialect {
 	public DmlTargetColumnQualifierSupport getDmlTargetColumnQualifierSupport() {
 		return DmlTargetColumnQualifierSupport.TABLE_ALIAS;
 	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return " from " + getDual();
+	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/HSQLLegacySqlAstTranslator.java

@@ -339,11 +339,6 @@ public class HSQLLegacySqlAstTranslator<T extends JdbcOperation> extends Abstrac
 		return false;
 	}
 
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return " from " + getDual();
-	}
-
 	private boolean supportsOffsetFetchClause() {
 		return getDialect().getVersion().isSameOrAfter( 2, 5 );
 	}

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/InformixDialect.java

@@ -854,4 +854,14 @@ public class InformixDialect extends Dialect {
 		jdbcTypeRegistry.addDescriptor( Types.NCLOB, ClobJdbcType.DEFAULT );
 		typeContributions.contributeJdbcType( VarcharUUIDJdbcType.INSTANCE );
 	}
+
+	@Override
+	public String getDual() {
+		return "(select 0 from systables where tabid=1)";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return " from " + getDual() + " dual";
+	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/InformixSqlAstTranslator.java

@@ -151,16 +151,6 @@ public class InformixSqlAstTranslator<T extends JdbcOperation> extends AbstractS
 		return false;
 	}
 
-	@Override
-	protected String getDual() {
-		return "(select 0 from systables where tabid=1)";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return " from " + getDual() + " dual";
-	}
-
 	@Override
 	protected void renderNull(Literal literal) {
 		if ( getParameterRenderingMode() == SqlAstNodeRenderingMode.NO_UNTYPED ) {

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/IngresDialect.java

@@ -557,4 +557,15 @@ public class IngresDialect extends Dialect {
 	public boolean supportsFetchClause(FetchClauseType type) {
 		return getVersion().isSameOrAfter( 9, 3 );
 	}
+
+	@Override
+	public String getDual() {
+		return "(select 0)";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		//this is only necessary if the query has a where clause
+		return " from " + getDual() + " dual";
+	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/IngresSqlAstTranslator.java

@@ -135,17 +135,6 @@ public class IngresSqlAstTranslator<T extends JdbcOperation> extends AbstractSql
 		return false;
 	}
 
-	@Override
-	protected String getDual() {
-		return "(select 0)";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		//this is only necessary if the query has a where clause
-		return " from " + getDual() + " dual";
-	}
-
 	@Override
 	protected boolean needsRowsToSkip() {
 		return !supportsOffsetFetchClause();

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/MariaDBLegacyDialect.java

@@ -262,4 +262,14 @@ public class MariaDBLegacyDialect extends MySQLLegacyDialect {
 
 		return super.buildIdentifierHelper( builder, dbMetaData );
 	}
+
+	@Override
+	public String getDual() {
+		return "dual";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return getVersion().isBefore( 10, 4 ) ? ( " from " + getDual() ) : "";
+	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/MariaDBLegacySqlAstTranslator.java

@@ -364,16 +364,6 @@ public class MariaDBLegacySqlAstTranslator<T extends JdbcOperation> extends Abst
 		return true;
 	}
 
-	@Override
-	protected String getDual() {
-		return "dual";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return getDialect().getVersion().isBefore( 10, 4 ) ? ( " from " + getDual() ) : "";
-	}
-
 	@Override
 	public MariaDBLegacyDialect getDialect() {
 		return this.dialect;

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/MaxDBDialect.java

@@ -328,4 +328,14 @@ public class MaxDBDialect extends Dialect {
 	public boolean supportsJdbcConnectionLobCreation(DatabaseMetaData databaseMetaData) {
 		return false;
 	}
+
+	@Override
+	public String getDual() {
+		return "dual";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return " from " + getDual();
+	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/MaxDBSqlAstTranslator.java

@@ -89,14 +89,4 @@ public class MaxDBSqlAstTranslator<T extends JdbcOperation> extends AbstractSqlA
 	protected boolean supportsRowValueConstructorSyntaxInQuantifiedPredicates() {
 		return false;
 	}
-
-	@Override
-	protected String getDual() {
-		return "dual";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return " from " + getDual();
-	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/MimerSQLDialect.java

@@ -341,4 +341,9 @@ public class MimerSQLDialect extends Dialect {
 	public IdentityColumnSupport getIdentityColumnSupport() {
 		return MimerSQLIdentityColumnSupport.INSTANCE;
 	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return " from " + getDual();
+	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/MimerSQLSqlAstTranslator.java

@@ -78,9 +78,4 @@ public class MimerSQLSqlAstTranslator<T extends JdbcOperation> extends AbstractS
 	protected boolean supportsRowValueConstructorSyntaxInQuantifiedPredicates() {
 		return false;
 	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return " from " + getDual();
-	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/MySQLLegacyDialect.java

@@ -1436,4 +1436,14 @@ public class MySQLLegacyDialect extends Dialect {
 		}
 		return sqlCheckConstraint;
 	}
+	@Override
+	public String getDual() {
+		return "dual";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return getVersion().isSameOrAfter( 8 ) ? "" : ( " from " + getDual() );
+	}
+
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/MySQLLegacySqlAstTranslator.java

@@ -387,16 +387,6 @@ public class MySQLLegacySqlAstTranslator<T extends JdbcOperation> extends Abstra
 		return getDialect().getVersion().isSameOrAfter( 8 );
 	}
 
-	@Override
-	protected String getDual() {
-		return "dual";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return getDialect().getVersion().isSameOrAfter( 8 ) ? "" : ( " from " + getDual() );
-	}
-
 	@Override
 	public MySQLLegacyDialect getDialect() {
 		return (MySQLLegacyDialect) DialectDelegateWrapper.extractRealDialect( super.getDialect() );

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/OracleLegacyDialect.java

@@ -397,20 +397,33 @@ public class OracleLegacyDialect extends Dialect {
 				}
 				break;
 			case INTEGER_BOOLEAN:
-				result = BooleanDecoder.toIntegerBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "1", "0" )
+						: BooleanDecoder.toIntegerBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
 				break;
 			case YN_BOOLEAN:
-				result = BooleanDecoder.toYesNoBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "'Y'", "'N'" )
+						: BooleanDecoder.toYesNoBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
 				break;
 			case BOOLEAN:
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "true", "false" )
+						: BooleanDecoder.toBoolean( from );
+				if ( result != null ) {
+					return result;
+				}
+				break;
 			case TF_BOOLEAN:
-				result = BooleanDecoder.toTrueFalseBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "'T'", "'F'" )
+						: BooleanDecoder.toTrueFalseBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
@@ -1577,4 +1590,14 @@ public class OracleLegacyDialect extends Dialect {
 		}
 		return sqlCheckConstraint;
 	}
+	@Override
+	public String getDual() {
+		return "dual";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return " from " + getDual();
+	}
+
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/OracleLegacySqlAstTranslator.java

@@ -672,16 +672,6 @@ public class OracleLegacySqlAstTranslator<T extends JdbcOperation> extends Abstr
 		return getDialect().getVersion().isSameOrAfter( 9 );
 	}
 
-	@Override
-	protected String getDual() {
-		return "dual";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return " from " + getDual();
-	}
-
 	private boolean supportsOffsetFetchClause() {
 		return getDialect().supportsFetchClause( FetchClauseType.ROWS_ONLY );
 	}

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/PostgreSQLLegacyDialect.java

@@ -58,6 +58,7 @@ import org.hibernate.procedure.internal.PostgreSQLCallableStatementSupport;
 import org.hibernate.procedure.spi.CallableStatementSupport;
 import org.hibernate.query.SemanticException;
 import org.hibernate.query.spi.QueryOptions;
+import org.hibernate.query.sqm.CastType;
 import org.hibernate.query.sqm.FetchClauseType;
 import org.hibernate.query.sqm.IntervalType;
 import org.hibernate.query.sqm.TemporalUnit;
@@ -416,6 +417,16 @@ public class PostgreSQLLegacyDialect extends Dialect {
 		}
 	}
 
+	@Override
+	public String castPattern(CastType from, CastType to) {
+		if ( from == CastType.STRING && to == CastType.BOOLEAN ) {
+			return "cast(?1 as ?2)";
+		}
+		else {
+			return super.castPattern( from, to );
+		}
+	}
+
 	/**
 	 * {@code microsecond} is the smallest unit for an {@code interval},
 	 * and the highest precision for a {@code timestamp}, so we could

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/RDMSOS2200Dialect.java

@@ -432,4 +432,14 @@ public class RDMSOS2200Dialect extends Dialect {
 	public String trimPattern(TrimSpec specification, boolean isWhitespace) {
 		return AbstractTransactSQLDialect.replaceLtrimRtrim( specification, isWhitespace );
 	}
+
+	@Override
+	public String getDual() {
+		return "rdms.rdms_dummy";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return " from " + getDual() + " where key_col=1";
+	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/RDMSOS2200SqlAstTranslator.java

@@ -122,14 +122,4 @@ public class RDMSOS2200SqlAstTranslator<T extends JdbcOperation> extends Abstrac
 	protected boolean supportsRowValueConstructorSyntaxInQuantifiedPredicates() {
 		return false;
 	}
-
-	@Override
-	protected String getDual() {
-		return "rdms.rdms_dummy";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return " from " + getDual() + " where key_col=1";
-	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/SingleStoreDialect.java

@@ -1410,4 +1410,9 @@ public class SingleStoreDialect extends Dialect {
 	 * @settingDefault {@code false}
 	 */
 	public static final String SINGLE_STORE_FOR_UPDATE_LOCK_ENABLED = "hibernate.dialect.singlestore.for_update_lock_enabled";
+
+	@Override
+	public String getDual() {
+		return "dual";
+	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/SingleStoreSqlAstTranslator.java

@@ -435,11 +435,6 @@ public class SingleStoreSqlAstTranslator<T extends JdbcOperation> extends Abstra
 		return false;
 	}
 
-	@Override
-	protected String getDual() {
-		return "dual";
-	}
-
 	@Override
 	public SingleStoreDialect getDialect() {
 		return this.dialect;

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/SybaseASELegacyDialect.java

@@ -694,4 +694,9 @@ public class SybaseASELegacyDialect extends SybaseLegacyDialect {
 		}
 		return new TopLimitHandler(false);
 	}
+
+	@Override
+	public String getDual() {
+		return "(select 1 c1)";
+	}
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/SybaseASELegacySqlAstTranslator.java

@@ -527,11 +527,6 @@ public class SybaseASELegacySqlAstTranslator<T extends JdbcOperation> extends Ab
 		return false;
 	}
 
-	@Override
-	protected String getDual() {
-		return "(select 1 c1)";
-	}
-
 	private boolean supportsTopClause() {
 		return getDialect().getVersion().isSameOrAfter( 12, 5 );
 	}

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/SybaseAnywhereDialect.java

@@ -213,4 +213,14 @@ public class SybaseAnywhereDialect extends SybaseDialect {
 		return TopLimitHandler.INSTANCE;
 	}
 
+	@Override
+	public String getDual() {
+		return "sys.dummy";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return " from " + getDual();
+	}
+
 }

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/SybaseAnywhereSqlAstTranslator.java

@@ -235,14 +235,4 @@ public class SybaseAnywhereSqlAstTranslator<T extends JdbcOperation> extends Abs
 	protected boolean supportsRowValueConstructorSyntaxInQuantifiedPredicates() {
 		return false;
 	}
-
-	@Override
-	protected String getDual() {
-		return "sys.dummy";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return " from " + getDual();
-	}
 }

hibernate-core/src/main/java/org/hibernate/dialect/DB2Dialect.java

@@ -58,6 +58,7 @@ import org.hibernate.metamodel.mapping.EntityMappingType;
 import org.hibernate.metamodel.spi.RuntimeModelCreationContext;
 import org.hibernate.procedure.internal.DB2CallableStatementSupport;
 import org.hibernate.procedure.spi.CallableStatementSupport;
+import org.hibernate.query.sqm.CastType;
 import org.hibernate.query.sqm.IntervalType;
 import org.hibernate.query.sqm.TemporalUnit;
 import org.hibernate.query.sqm.mutation.internal.cte.CteInsertStrategy;
@@ -1215,6 +1216,16 @@ public class DB2Dialect extends Dialect {
 		return super.extractPattern( unit );
 	}
 
+	@Override
+	public String castPattern(CastType from, CastType to) {
+		if ( from == CastType.STRING && to == CastType.BOOLEAN ) {
+			return "cast(?1 as ?2)";
+		}
+		else {
+			return super.castPattern( from, to );
+		}
+	}
+
 	@Override
 	public int getInExpressionCountLimit() {
 		return BIND_PARAMETERS_NUMBER_LIMIT;
@@ -1282,4 +1293,14 @@ public class DB2Dialect extends Dialect {
 	public boolean supportsFromClauseInUpdate() {
 		return getDB2Version().isSameOrAfter( 11 );
 	}
+
+	@Override
+	public String getDual() {
+		return "sysibm.dual";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return " from " + getDual();
+	}
 }

hibernate-core/src/main/java/org/hibernate/dialect/DB2SqlAstTranslator.java

@@ -585,16 +585,6 @@ public class DB2SqlAstTranslator<T extends JdbcOperation> extends AbstractSqlAst
 		return false;
 	}
 
-	@Override
-	protected String getDual() {
-		return "sysibm.dual";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return " from " + getDual();
-	}
-
 	@Override
 	protected void visitReturningColumns(List<ColumnReference> returningColumns) {
 		// For DB2 we use #renderReturningClause to render a wrapper around the DML statement

hibernate-core/src/main/java/org/hibernate/dialect/Dialect.java

@@ -1455,7 +1455,7 @@ public abstract class Dialect implements ConversionContext, TypeContributor, Fun
 			case INTEGER_BOOLEAN:
 				switch ( from ) {
 					case STRING:
-						return "case ?1 when 'T' then 1 when 'Y' then 1 when 'F' then 0 when 'N' then 0 else null end";
+						return buildStringToBooleanCast( "1", "0" );
 					case INTEGER:
 					case LONG:
 						return "abs(sign(?1))";
@@ -1470,7 +1470,7 @@ public abstract class Dialect implements ConversionContext, TypeContributor, Fun
 			case YN_BOOLEAN:
 				switch ( from ) {
 					case STRING:
-						return "case ?1 when 'T' then 'Y' when 'Y' then 'Y' when 'F' then 'N' when 'N' then 'N' else null end";
+						return buildStringToBooleanCast( "'Y'", "'N'" );
 					case INTEGER_BOOLEAN:
 						return "case ?1 when 1 then 'Y' when 0 then 'N' else null end";
 					case INTEGER:
@@ -1485,7 +1485,7 @@ public abstract class Dialect implements ConversionContext, TypeContributor, Fun
 			case TF_BOOLEAN:
 				switch ( from ) {
 					case STRING:
-						return "case ?1 when 'T' then 'T' when 'Y' then 'T' when 'F' then 'F' when 'N' then 'F' else null end";
+						return buildStringToBooleanCast( "'T'", "'F'" );
 					case INTEGER_BOOLEAN:
 						return "case ?1 when 1 then 'T' when 0 then 'F' else null end";
 					case INTEGER:
@@ -1500,7 +1500,7 @@ public abstract class Dialect implements ConversionContext, TypeContributor, Fun
 			case BOOLEAN:
 				switch ( from ) {
 					case STRING:
-						return "case ?1 when 'T' then true when 'Y' then true when 'F' then false when 'N' then false else null end";
+						return buildStringToBooleanCast( "true", "false" );
 					case INTEGER_BOOLEAN:
 					case INTEGER:
 					case LONG:
@@ -1515,6 +1515,153 @@ public abstract class Dialect implements ConversionContext, TypeContributor, Fun
 		return "cast(?1 as ?2)";
 	}
 
+	protected static final String[] TRUE_STRING_VALUES = new String[] { "t", "true", "y", "1" };
+	protected static final String[] FALSE_STRING_VALUES = new String[] { "f", "false", "n", "0" };
+
+	protected String buildStringToBooleanCast(String trueValue, String falseValue) {
+		final boolean supportsValuesList = supportsValuesList();
+		final StringBuilder sb = new StringBuilder();
+		sb.append( "(select v.x from (" );
+		if ( supportsValuesList ) {
+			sb.append( "values (" );
+			sb.append( trueValue );
+			sb.append( "),(" );
+			sb.append( falseValue );
+			sb.append( ")) v(x)" );
+		}
+		else {
+			sb.append( "select " );
+			sb.append( trueValue );
+			sb.append( " x");
+			sb.append( getFromDualForSelectOnly() );
+			sb.append(" union all select " );
+			sb.append( falseValue );
+			sb.append( getFromDualForSelectOnly() );
+			sb.append( ") v" );
+		}
+		sb.append( " left join (" );
+		if ( supportsValuesList ) {
+			sb.append( "values" );
+			char separator = ' ';
+			for ( String trueStringValue : Dialect.TRUE_STRING_VALUES ) {
+				sb.append( separator );
+				sb.append( "('" );
+				sb.append( trueStringValue );
+				sb.append( "'," );
+				sb.append( trueValue );
+				sb.append( ')' );
+				separator = ',';
+			}
+			for ( String falseStringValue : Dialect.FALSE_STRING_VALUES ) {
+				sb.append( ",('" );
+				sb.append( falseStringValue );
+				sb.append( "'," );
+				sb.append( falseValue );
+				sb.append( ')' );
+			}
+			sb.append( ") t(k,v)" );
+		}
+		else {
+			sb.append( "select '" );
+			sb.append( Dialect.TRUE_STRING_VALUES[0] );
+			sb.append( "' k," );
+			sb.append( trueValue );
+			sb.append( " v" );
+			sb.append( getFromDualForSelectOnly() );
+			for ( int i = 1; i < Dialect.TRUE_STRING_VALUES.length; i++ ) {
+				sb.append( " union all select '" );
+				sb.append( Dialect.TRUE_STRING_VALUES[i] );
+				sb.append( "'," );
+				sb.append( trueValue );
+				sb.append( getFromDualForSelectOnly() );
+			}
+			for ( String falseStringValue : Dialect.FALSE_STRING_VALUES ) {
+				sb.append( " union all select '" );
+				sb.append( falseStringValue );
+				sb.append( "'," );
+				sb.append( falseValue );
+				sb.append( getFromDualForSelectOnly() );
+			}
+			sb.append( ") t" );
+		}
+		sb.append( " on " );
+		sb.append( getLowercaseFunction() );
+		sb.append( "(?1)=t.k where t.v is null or v.x=t.v)" );
+		return sb.toString();
+	}
+
+	protected String buildStringToBooleanCastDecode(String trueValue, String falseValue) {
+		final boolean supportsValuesList = supportsValuesList();
+		final StringBuilder sb = new StringBuilder();
+		sb.append( "(select v.x from (" );
+		if ( supportsValuesList ) {
+			sb.append( "values (" );
+			sb.append( trueValue );
+			sb.append( "),(" );
+			sb.append( falseValue );
+			sb.append( ")) v(x)" );
+		}
+		else {
+			sb.append( "select " );
+			sb.append( trueValue );
+			sb.append( " x");
+			sb.append( getFromDualForSelectOnly() );
+			sb.append(" union all select " );
+			sb.append( falseValue );
+			sb.append( getFromDualForSelectOnly() );
+			sb.append( ") v" );
+		}
+		sb.append( ", (" );
+		if ( supportsValuesList ) {
+			sb.append( "values (" );
+			sb.append( buildStringToBooleanDecode( trueValue, falseValue ) );
+			sb.append( ")) t(v)" );
+		}
+		else {
+			sb.append( "select " );
+			sb.append( buildStringToBooleanDecode( trueValue, falseValue ) );
+			sb.append( " v");
+			sb.append( getFromDualForSelectOnly() );
+			sb.append(") t" );
+		}
+		sb.append( " where t.v is null or v.x=t.v)" );
+		return sb.toString();
+	}
+
+	protected String buildStringToBooleanDecode(String trueValue, String falseValue) {
+		final StringBuilder sb = new StringBuilder();
+		sb.append( "decode(" );
+		sb.append( getLowercaseFunction() );
+		sb.append( "(?1)" );
+		for ( String trueStringValue : TRUE_STRING_VALUES ) {
+			sb.append( ",'" );
+			sb.append( trueStringValue );
+			sb.append( "'," );
+			sb.append( trueValue );
+		}
+		for ( String falseStringValue : FALSE_STRING_VALUES ) {
+			sb.append( ",'" );
+			sb.append( falseStringValue );
+			sb.append( "'," );
+			sb.append( falseValue );
+		}
+		sb.append( ",null)" );
+		return sb.toString();
+	}
+
+	/**
+	 * Returns a table expression that has one row.
+	 *
+	 * @return the SQL equivalent to Oracle's {@code dual}.
+	 */
+	public String getDual() {
+		return "(values(0))";
+	}
+
+	public String getFromDualForSelectOnly() {
+		return "";
+	}
+
 	/**
 	 * Obtain a pattern for the SQL equivalent to a
 	 * {@code trim()} function call. The resulting

hibernate-core/src/main/java/org/hibernate/dialect/H2Dialect.java

@@ -42,6 +42,7 @@ import org.hibernate.internal.util.StringHelper;
 import org.hibernate.metamodel.mapping.EntityMappingType;
 import org.hibernate.metamodel.spi.RuntimeModelCreationContext;
 import org.hibernate.persister.entity.mutation.EntityMutationTarget;
+import org.hibernate.query.sqm.CastType;
 import org.hibernate.query.sqm.FetchClauseType;
 import org.hibernate.query.sqm.IntervalType;
 import org.hibernate.query.sqm.TemporalUnit;
@@ -442,6 +443,16 @@ public class H2Dialect extends Dialect {
 				: super.extractPattern(unit);
 	}
 
+	@Override
+	public String castPattern(CastType from, CastType to) {
+		if ( from == CastType.STRING && to == CastType.BOOLEAN ) {
+			return "cast(?1 as ?2)";
+		}
+		else {
+			return super.castPattern( from, to );
+		}
+	}
+
 	@Override @SuppressWarnings("deprecation")
 	public String timestampaddPattern(TemporalUnit unit, TemporalType temporalType, IntervalType intervalType) {
 		if ( intervalType != null ) {
@@ -1010,4 +1021,14 @@ public class H2Dialect extends Dialect {
 		return true;
 	}
 
+	@Override
+	public boolean supportsValuesList() {
+		return true;
+	}
+
+	@Override
+	public String getDual() {
+		return "dual";
+	}
+
 }

hibernate-core/src/main/java/org/hibernate/dialect/H2SqlAstTranslator.java

@@ -358,11 +358,6 @@ public class H2SqlAstTranslator<T extends JdbcOperation> extends SqlAstTranslato
 		return true;
 	}
 
-	@Override
-	protected String getDual() {
-		return "dual";
-	}
-
 	private boolean supportsOffsetFetchClause() {
 		return true;
 	}

hibernate-core/src/main/java/org/hibernate/dialect/HANADialect.java

@@ -1996,4 +1996,14 @@ public class HANADialect extends Dialect {
 	public String getForUpdateString(LockMode lockMode) {
 		return super.getForUpdateString(lockMode);
 	}
+
+	@Override
+	public String getDual() {
+		return "sys.dummy";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return " from " + getDual();
+	}
 }

hibernate-core/src/main/java/org/hibernate/dialect/HANASqlAstTranslator.java

@@ -249,16 +249,6 @@ public class HANASqlAstTranslator<T extends JdbcOperation> extends AbstractSqlAs
 		return false;
 	}
 
-	@Override
-	protected String getDual() {
-		return "sys.dummy";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return " from " + getDual();
-	}
-
 	@Override
 	protected void renderInsertIntoNoColumns(TableInsertStandard tableInsert) {
 		throw new MappingException(

hibernate-core/src/main/java/org/hibernate/dialect/HSQLDialect.java

@@ -250,25 +250,33 @@ public class HSQLDialect extends Dialect {
 				}
 				break;
 			case BOOLEAN:
-				result = BooleanDecoder.toBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "true", "false" )
+						: BooleanDecoder.toBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
 				break;
 			case INTEGER_BOOLEAN:
-				result = BooleanDecoder.toIntegerBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "1", "0" )
+						: BooleanDecoder.toIntegerBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
 				break;
 			case YN_BOOLEAN:
-				result = BooleanDecoder.toYesNoBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "'Y'", "'N'" )
+						: BooleanDecoder.toYesNoBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
 				break;
 			case TF_BOOLEAN:
-				result = BooleanDecoder.toTrueFalseBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "'T'", "'F'" )
+						: BooleanDecoder.toTrueFalseBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
@@ -610,6 +618,11 @@ public class HSQLDialect extends Dialect {
 		return true;
 	}
 
+	@Override
+	public boolean supportsValuesList() {
+		return true;
+	}
+
 	@Override
 	public IdentityColumnSupport getIdentityColumnSupport() {
 		return identityColumnSupport;
@@ -690,4 +703,9 @@ public class HSQLDialect extends Dialect {
 	public DmlTargetColumnQualifierSupport getDmlTargetColumnQualifierSupport() {
 		return DmlTargetColumnQualifierSupport.TABLE_ALIAS;
 	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return " from " + getDual();
+	}
 }

hibernate-core/src/main/java/org/hibernate/dialect/HSQLSqlAstTranslator.java

@@ -333,11 +333,6 @@ public class HSQLSqlAstTranslator<T extends JdbcOperation> extends AbstractSqlAs
 		return false;
 	}
 
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return " from " + getDual();
-	}
-
 	private boolean supportsOffsetFetchClause() {
 		return true;
 	}

hibernate-core/src/main/java/org/hibernate/dialect/MariaDBDialect.java

@@ -281,4 +281,9 @@ public class MariaDBDialect extends MySQLDialect {
 
 		return super.buildIdentifierHelper( builder, dbMetaData );
 	}
+
+	@Override
+	public String getDual() {
+		return "dual";
+	}
 }

hibernate-core/src/main/java/org/hibernate/dialect/MariaDBSqlAstTranslator.java

@@ -367,11 +367,6 @@ public class MariaDBSqlAstTranslator<T extends JdbcOperation> extends AbstractSq
 		return true;
 	}
 
-	@Override
-	protected String getDual() {
-		return "dual";
-	}
-
 	@Override
 	public MariaDBDialect getDialect() {
 		return this.dialect;

hibernate-core/src/main/java/org/hibernate/dialect/MySQLDialect.java

@@ -1516,4 +1516,9 @@ public class MySQLDialect extends Dialect {
 	public boolean supportsBindingNullSqlTypeForSetNull() {
 		return true;
 	}
+
+	@Override
+	public String getDual() {
+		return "dual";
+	}
 }

hibernate-core/src/main/java/org/hibernate/dialect/MySQLSqlAstTranslator.java

@@ -433,11 +433,6 @@ public class MySQLSqlAstTranslator<T extends JdbcOperation> extends AbstractSqlA
 		return true;
 	}
 
-	@Override
-	protected String getDual() {
-		return "dual";
-	}
-
 	@Override
 	public MySQLDialect getDialect() {
 		return (MySQLDialect) DialectDelegateWrapper.extractRealDialect( super.getDialect() );

hibernate-core/src/main/java/org/hibernate/dialect/OracleDialect.java

@@ -462,25 +462,33 @@ public class OracleDialect extends Dialect {
 				}
 				break;
 			case INTEGER_BOOLEAN:
-				result = BooleanDecoder.toIntegerBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "1", "0" )
+						: BooleanDecoder.toIntegerBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
 				break;
 			case YN_BOOLEAN:
-				result = BooleanDecoder.toYesNoBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "'Y'", "'N'" )
+						: BooleanDecoder.toYesNoBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
 				break;
 			case BOOLEAN:
-				result = BooleanDecoder.toBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "true", "false" )
+						: BooleanDecoder.toBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
 				break;
 			case TF_BOOLEAN:
-				result = BooleanDecoder.toTrueFalseBoolean( from );
+				result = from == CastType.STRING
+						? buildStringToBooleanCastDecode( "'T'", "'F'" )
+						: BooleanDecoder.toTrueFalseBoolean( from );
 				if ( result != null ) {
 					return result;
 				}
@@ -1696,4 +1704,14 @@ public class OracleDialect extends Dialect {
 				? sqlCheckConstraint + " " + checkConstraint.getOptions()
 				: sqlCheckConstraint;
 	}
+	@Override
+	public String getDual() {
+		return "dual";
+	}
+
+	@Override
+	public String getFromDualForSelectOnly() {
+		return getVersion().isSameOrAfter( 23 ) ? "" : ( " from " + getDual() );
+	}
+
 }

hibernate-core/src/main/java/org/hibernate/dialect/OracleSqlAstTranslator.java

@@ -615,16 +615,6 @@ public class OracleSqlAstTranslator<T extends JdbcOperation> extends SqlAstTrans
 		return false;
 	}
 
-	@Override
-	protected String getDual() {
-		return "dual";
-	}
-
-	@Override
-	protected String getFromDualForSelectOnly() {
-		return getDialect().getVersion().isSameOrAfter( 23 ) ? "" : ( " from " + getDual() );
-	}
-
 	private boolean supportsOffsetFetchClause() {
 		return getDialect().supportsFetchClause( FetchClauseType.ROWS_ONLY );
 	}

hibernate-core/src/main/java/org/hibernate/dialect/PostgreSQLDialect.java

@@ -56,6 +56,7 @@ import org.hibernate.procedure.internal.PostgreSQLCallableStatementSupport;
 import org.hibernate.procedure.spi.CallableStatementSupport;
 import org.hibernate.query.SemanticException;
 import org.hibernate.query.spi.QueryOptions;
+import org.hibernate.query.sqm.CastType;
 import org.hibernate.query.sqm.FetchClauseType;
 import org.hibernate.query.sqm.IntervalType;
 import org.hibernate.query.sqm.TemporalUnit;
@@ -436,6 +437,16 @@ public class PostgreSQLDialect extends Dialect {
 		};
 	}
 
+	@Override
+	public String castPattern(CastType from, CastType to) {
+		if ( from == CastType.STRING && to == CastType.BOOLEAN ) {
+			return "cast(?1 as ?2)";
+		}
+		else {
+			return super.castPattern( from, to );
+		}
+	}
+
 	/**
 	 * {@code microsecond} is the smallest unit for an {@code interval},
 	 * and the highest precision for a {@code timestamp}, so we could

hibernate-core/src/main/java/org/hibernate/dialect/SybaseASEDialect.java

@@ -710,4 +710,9 @@ public class SybaseASEDialect extends SybaseDialect {
 	public LimitHandler getLimitHandler() {
 		return new TopLimitHandler(false);
 	}
+
+	@Override
+	public String getDual() {
+		return "(select 1 c1)";
+	}
 }

hibernate-core/src/main/java/org/hibernate/dialect/SybaseASESqlAstTranslator.java

@@ -506,11 +506,6 @@ public class SybaseASESqlAstTranslator<T extends JdbcOperation> extends Abstract
 		return false;
 	}
 
-	@Override
-	protected String getDual() {
-		return "(select 1 c1)";
-	}
-
 	private boolean supportsParameterOffsetFetchExpression() {
 		return false;
 	}

hibernate-core/src/main/java/org/hibernate/dialect/TiDBDialect.java

@@ -187,4 +187,9 @@ public class TiDBDialect extends MySQLDialect {
 				? "timestampadd(microsecond,?2*1e6,?3)"
 				: super.timestampaddPattern(unit, temporalType, intervalType);
 	}
+
+	@Override
+	public String getDual() {
+		return "dual";
+	}
 }

hibernate-core/src/main/java/org/hibernate/dialect/TiDBSqlAstTranslator.java

@@ -330,11 +330,6 @@ public class TiDBSqlAstTranslator<T extends JdbcOperation> extends AbstractSqlAs
 		return false;
 	}
 
-	@Override
-	protected String getDual() {
-		return "dual";
-	}
-
 	@Override
 	protected String getForShare(int timeoutMillis) {
 		if ( timeoutMillis == LockOptions.NO_WAIT ) {

hibernate-core/src/main/java/org/hibernate/sql/ast/spi/AbstractSqlAstTranslator.java

@@ -8579,11 +8579,11 @@ public abstract class AbstractSqlAstTranslator<T extends JdbcOperation> implemen
 	 * @return the SQL equivalent to Oracle's {@code dual}.
 	 */
 	protected String getDual() {
-		return "(values(0))";
+		return dialect.getDual();
 	}
 
 	protected String getFromDualForSelectOnly() {
-		return "";
+		return dialect.getFromDualForSelectOnly();
 	}
 
 	protected enum LockStrategy {

hibernate-core/src/test/java/org/hibernate/orm/test/query/hql/FunctionTests.java

@@ -5,6 +5,9 @@
 package org.hibernate.orm.test.query.hql;
 
 import org.hamcrest.Matchers;
+
+import org.hibernate.HibernateException;
+import org.hibernate.JDBCException;
 import org.hibernate.QueryException;
 import org.hibernate.community.dialect.AltibaseDialect;
 import org.hibernate.community.dialect.InformixDialect;
@@ -22,6 +25,8 @@ import org.hibernate.dialect.SQLServerDialect;
 import org.hibernate.dialect.SybaseDialect;
 import org.hibernate.dialect.TiDBDialect;
 import org.hibernate.query.sqm.produce.function.FunctionArgumentException;
+import org.hibernate.sql.exec.ExecutionException;
+
 import org.hibernate.testing.orm.junit.JiraKey;
 import org.hibernate.testing.orm.domain.StandardDomainModel;
 import org.hibernate.testing.orm.domain.gambit.EntityOfBasics;
@@ -30,6 +35,7 @@ import org.hibernate.testing.orm.domain.gambit.EntityOfMaps;
 import org.hibernate.testing.orm.domain.gambit.SimpleEntity;
 import org.hibernate.testing.orm.junit.DialectFeatureChecks;
 import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.Jira;
 import org.hibernate.testing.orm.junit.JiraKey;
 import org.hibernate.testing.orm.junit.RequiresDialect;
 import org.hibernate.testing.orm.junit.RequiresDialectFeature;
@@ -63,6 +69,7 @@ import static org.hamcrest.Matchers.isOneOf;
 import static org.hibernate.testing.orm.domain.gambit.EntityOfBasics.Gender.FEMALE;
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertInstanceOf;
 import static org.junit.jupiter.api.Assertions.fail;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
@@ -1028,6 +1035,44 @@ public class FunctionTests {
 		);
 	}
 
+	@Test
+	@Jira("https://hibernate.atlassian.net/browse/HHH-18447")
+	public void testCastStringToBoolean(SessionFactoryScope scope) {
+		scope.inTransaction( session -> {
+			assertThat( session.createQuery("select cast('1' as Boolean)", Boolean.class).getSingleResult(), is(true) );
+			assertThat( session.createQuery("select cast('0' as Boolean)", Boolean.class).getSingleResult(), is(false) );
+			assertThat( session.createQuery("select cast('y' as Boolean)", Boolean.class).getSingleResult(), is(true) );
+			assertThat( session.createQuery("select cast('n' as Boolean)", Boolean.class).getSingleResult(), is(false) );
+			assertThat( session.createQuery("select cast('Y' as Boolean)", Boolean.class).getSingleResult(), is(true) );
+			assertThat( session.createQuery("select cast('N' as Boolean)", Boolean.class).getSingleResult(), is(false) );
+			assertThat( session.createQuery("select cast('t' as Boolean)", Boolean.class).getSingleResult(), is(true) );
+			assertThat( session.createQuery("select cast('f' as Boolean)", Boolean.class).getSingleResult(), is(false) );
+			assertThat( session.createQuery("select cast('T' as Boolean)", Boolean.class).getSingleResult(), is(true) );
+			assertThat( session.createQuery("select cast('F' as Boolean)", Boolean.class).getSingleResult(), is(false) );
+			assertThat( session.createQuery("select cast('true' as Boolean)", Boolean.class).getSingleResult(), is(true) );
+			assertThat( session.createQuery("select cast('false' as Boolean)", Boolean.class).getSingleResult(), is(false) );
+			assertThat( session.createQuery("select cast('TRUE' as Boolean)", Boolean.class).getSingleResult(), is(true) );
+			assertThat( session.createQuery("select cast('FALSE' as Boolean)", Boolean.class).getSingleResult(), is(false) );
+		});
+	}
+
+	@Test
+	@Jira("https://hibernate.atlassian.net/browse/HHH-18447")
+	public void testCastInvalidStringToBoolean(SessionFactoryScope scope) {
+		scope.inTransaction( session -> {
+			try {
+				session.createQuery( "select cast('bla' as Boolean)", Boolean.class ).getSingleResult();
+				fail("Casting invalid boolean string should fail");
+			}
+			catch ( HibernateException e ) {
+				// Expected
+				if ( !( e instanceof JDBCException || e instanceof ExecutionException ) ) {
+					throw e;
+				}
+			}
+		} );
+	}
+
 	@Test
 	@SkipForDialect(dialectClass = DB2Dialect.class, matchSubTypes = true)
 	@SkipForDialect(dialectClass = DerbyDialect.class)