HHH-18892 add hex() function

documentation/src/main/asciidoc/querylanguage/Expressions.adoc

@@ -841,6 +841,7 @@ Naturally, there are a good number of functions for working with strings.
 | `replace()` | Replace every occurrence of a pattern in a string | `replace(str, patt, rep)` | ✔ / ✖
 | `repeat()` | Concatenate a string with itself multiple times | `repeat(str, times)` | ✖ / ✖
 | `collate()` | Select a collation | `collate(p.name as collation)` | ✖ / ✖
+| `hex()` | Encode a binary value as a hexadecimal string | `hex(image.bytes)` | ✖ / ✖
 |===
 
 Let's take a closer look at just some of these.

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

@@ -503,6 +503,7 @@ public class CockroachDialect extends Dialect {
 		);
 		functionContributions.getFunctionRegistry().registerAlternateKey( "truncate", "trunc" );
 
+		functionFactory.hex( "encode(?1, 'hex')" );
 		functionFactory.sha( "digest(?1, 'sha256')" );
 		functionFactory.md5( "digest(?1, 'md5')" );
 	}

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

@@ -453,6 +453,7 @@ public class DB2Dialect extends Dialect {
 		functionFactory.unnest_db2( getMaximumSeriesSize() );
 		functionFactory.generateSeries_recursive( getMaximumSeriesSize(), false, true );
 
+		functionFactory.hex( "hex(?1)" );
 		functionFactory.sha( "hash(?1, 2)" );
 		functionFactory.md5( "hash(?1, 0)" );
 	}

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

@@ -369,6 +369,7 @@ public class H2Dialect extends Dialect {
 		functionFactory.generateSeries_h2( getMaximumSeriesSize() );
 		functionFactory.jsonTable_h2( getMaximumArraySize() );
 
+		functionFactory.hex( "rawtohex(?1)" );
 		functionFactory.sha( "hash('SHA-256', ?1)" );
 		functionFactory.md5( "hash('MD5', ?1)" );
 	}

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

@@ -518,6 +518,7 @@ public class HANADialect extends Dialect {
 //		functionFactory.xmlextract();
 		functionFactory.generateSeries_hana( getMaximumSeriesSize() );
 
+		functionFactory.hex( "to_hex(?1)" );
 		functionFactory.sha( "hash_sha256(?1)" );
 		functionFactory.md5( "hash_md5(?1)" );
 	}

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

@@ -222,6 +222,8 @@ public class HSQLDialect extends Dialect {
 				functionContributions.getTypeConfiguration(),
 				SqlAstNodeRenderingMode.NO_PLAIN_PARAMETER
 		) );
+
+		functionFactory.hex( "hex(?1)" );
 	}
 
 	/**

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

@@ -687,6 +687,7 @@ public class MySQLDialect extends Dialect {
 			functionFactory.generateSeries_recursive( getMaximumSeriesSize(), false, false );
 		}
 
+		functionFactory.hex( "hex(?1)" );
 		functionFactory.sha( "unhex(sha2(?1, 256))" );
 		functionFactory.md5( "unhex(md5(?1))" );
 	}

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

@@ -441,6 +441,7 @@ public class OracleDialect extends Dialect {
 		functionFactory.generateSeries_recursive( getMaximumSeriesSize(), true, false );
 		functionFactory.jsonTable_oracle();
 
+		functionFactory.hex( "rawtohex(?1)" );
 		functionFactory.sha( "standard_hash(?1, 'SHA256')" );
 		functionFactory.md5( "standard_hash(?1, 'MD5')" );
 	}

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

@@ -690,6 +690,7 @@ public class PostgreSQLDialect extends Dialect {
 		}
 		functionFactory.generateSeries( null, "ordinality", false );
 
+		functionFactory.hex( "encode(?1, 'hex')" );
 		functionFactory.sha( "sha256(?1)" );
 		functionFactory.md5( "decode(md5(?1), 'hex')" );
 	}

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

@@ -488,6 +488,7 @@ public class SQLServerDialect extends AbstractTransactSQLDialect {
 			}
 		}
 
+		functionFactory.hex( "convert(varchar(MAX), ?1, 2)" );
 		functionFactory.sha( "hashbytes('SHA2_256', ?1)" );
 		functionFactory.md5( "hashbytes('MD5', ?1)" );
 	}

hibernate-core/src/main/java/org/hibernate/dialect/function/CommonFunctionFactory.java

@@ -389,7 +389,8 @@ public class CommonFunctionFactory {
 	}
 
 	/**
-	 * CockroachDB lacks implicit casting: https://github.com/cockroachdb/cockroach/issues/89965
+	 * CockroachDB lacks
+	 * <a href="https://github.com/cockroachdb/cockroach/issues/89965">implicit casting</a>
 	 */
 	public void median_percentileCont_castDouble() {
 		functionRegistry.patternDescriptorBuilder(
@@ -2325,6 +2326,14 @@ public class CommonFunctionFactory {
 				.register();
 	}
 
+	public void hex(String pattern) {
+		functionRegistry.patternDescriptorBuilder( "hex", pattern )
+				.setInvariantType(stringType)
+				.setParameterTypes( BINARY )
+				.setExactArgumentCount( 1 )
+				.register();
+	}
+
 	public void md5(String pattern) {
 		functionRegistry.patternDescriptorBuilder( "md5", pattern )
 				.setInvariantType(binaryType)

hibernate-core/src/main/java/org/hibernate/query/sqm/produce/function/ArgumentTypesValidator.java

@@ -248,6 +248,7 @@ public class ArgumentTypesValidator implements ArgumentsValidator {
 			case TEMPORAL -> jdbcType.isTemporal();
 			case DATE -> jdbcType.hasDatePart();
 			case TIME -> jdbcType.hasTimePart();
+			case BINARY -> jdbcType.isBinary();
 			case SPATIAL -> jdbcType.isSpatial();
 			case JSON -> jdbcType.isJson();
 			case IMPLICIT_JSON -> jdbcType.isImplicitJson();

hibernate-core/src/main/java/org/hibernate/query/sqm/produce/function/FunctionParameterType.java

@@ -48,6 +48,10 @@ public enum FunctionParameterType {
 	 * a logical expression (predicate)
 	 */
 	BOOLEAN,
+	/**
+	 * @see org.hibernate.type.SqlTypes#isBinaryType(int)
+	 */
+	BINARY,
 	/**
 	 * Indicates a parameter that accepts any type
 	 */

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

@@ -23,6 +23,7 @@ import org.hibernate.dialect.OracleDialect;
 import org.hibernate.dialect.PostgreSQLDialect;
 import org.hibernate.dialect.PostgresPlusDialect;
 import org.hibernate.dialect.SQLServerDialect;
+import org.hibernate.dialect.SybaseASEDialect;
 import org.hibernate.dialect.SybaseDialect;
 import org.hibernate.dialect.TiDBDialect;
 import org.hibernate.query.sqm.produce.function.FunctionArgumentException;
@@ -62,6 +63,7 @@ import java.time.ZoneOffset;
 import java.time.temporal.ChronoUnit;
 import java.util.Date;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.UUID;
 
@@ -2627,4 +2629,14 @@ public class FunctionTests {
 			}
 		});
 	}
+
+	@Test
+	@SkipForDialect(dialectClass = SybaseASEDialect.class)
+	public void testHexFunction(SessionFactoryScope scope) {
+		scope.inTransaction(s -> {
+			assertEquals( "DEADBEEF",
+					s.createSelectionQuery("select hex({0xDE, 0xAD, 0xBE, 0xEF})", String.class)
+							.getSingleResult().toUpperCase( Locale.ROOT ) );
+		});
+	}
 }