Fix some JSON function rendering issues on TiDB

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

@@ -127,7 +127,7 @@ public class MariaDBLegacyDialect extends MySQLLegacyDialect {
 	@Override
 	public AggregateSupport getAggregateSupport() {
 		return getVersion().isSameOrAfter( 10, 2 )
-				? MySQLAggregateSupport.LONGTEXT_INSTANCE
+				? MySQLAggregateSupport.forMariaDB( this )
 				: AggregateSupportImpl.INSTANCE;
 	}
 

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

@@ -392,9 +392,7 @@ public class MySQLLegacyDialect extends Dialect {
 
 	@Override
 	public AggregateSupport getAggregateSupport() {
-		return getMySQLVersion().isSameOrAfter( 5, 7 )
+		return MySQLAggregateSupport.forMySQL( this );
-				? MySQLAggregateSupport.JSON_INSTANCE
-				: super.getAggregateSupport();
 	}
 
 	@Deprecated

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

@@ -125,7 +125,7 @@ public class MariaDBDialect extends MySQLDialect {
 
 	@Override
 	public AggregateSupport getAggregateSupport() {
-		return MySQLAggregateSupport.LONGTEXT_INSTANCE;
+		return MySQLAggregateSupport.forMariaDB( this );
 	}
 
 	@Override

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

@@ -440,7 +440,7 @@ public class MySQLDialect extends Dialect {
 
 	@Override
 	public AggregateSupport getAggregateSupport() {
-		return MySQLAggregateSupport.JSON_INSTANCE;
+		return MySQLAggregateSupport.forMySQL( this );
 	}
 
 	@Deprecated(since="6.4")

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

@@ -5,6 +5,8 @@
 package org.hibernate.dialect;
 
 import org.hibernate.LockOptions;
+import org.hibernate.dialect.aggregate.AggregateSupport;
+import org.hibernate.dialect.aggregate.MySQLAggregateSupport;
 import org.hibernate.dialect.sequence.SequenceSupport;
 import org.hibernate.dialect.sequence.TiDBSequenceSupport;
 import org.hibernate.engine.jdbc.dialect.spi.DialectResolutionInfo;
@@ -90,6 +92,11 @@ public class TiDBDialect extends MySQLDialect {
 		return TiDBSequenceSupport.INSTANCE;
 	}
 
+	@Override
+	public AggregateSupport getAggregateSupport() {
+		return MySQLAggregateSupport.forTiDB( this );
+	}
+
 	@Override
 	public SequenceInformationExtractor getSequenceInformationExtractor() {
 		return SequenceInformationExtractorTiDBDatabaseImpl.INSTANCE;

hibernate-core/src/main/java/org/hibernate/dialect/aggregate/MySQLAggregateSupport.java

@@ -4,6 +4,7 @@
  */
 package org.hibernate.dialect.aggregate;
 
+import org.hibernate.dialect.Dialect;
 import org.hibernate.internal.util.StringHelper;
 import org.hibernate.mapping.Column;
 import org.hibernate.metamodel.mapping.JdbcMapping;
@@ -48,13 +49,32 @@ import static org.hibernate.type.SqlTypes.VARCHAR;
 
 public class MySQLAggregateSupport extends AggregateSupportImpl {
 
-	public static final AggregateSupport JSON_INSTANCE = new MySQLAggregateSupport( true );
+	private static final AggregateSupport JSON_INSTANCE = new MySQLAggregateSupport( true, false );
-	public static final AggregateSupport LONGTEXT_INSTANCE = new MySQLAggregateSupport( false );
+	private static final AggregateSupport JSON_WITH_UUID_INSTANCE = new MySQLAggregateSupport( true, true );
+	private static final AggregateSupport LONGTEXT_INSTANCE = new MySQLAggregateSupport( false, false );
 
 	private final boolean jsonType;
+	private final boolean uuidFunctions;
 
-	public MySQLAggregateSupport(boolean jsonType) {
+	private MySQLAggregateSupport(boolean jsonType, boolean uuidFunctions) {
 		this.jsonType = jsonType;
+		this.uuidFunctions = uuidFunctions;
+	}
+
+	public static AggregateSupport forMySQL(Dialect dialect) {
+		return dialect.getVersion().isSameOrAfter( 8 )
+				? JSON_WITH_UUID_INSTANCE
+				: dialect.getVersion().isSameOrAfter( 5, 7 )
+						? JSON_INSTANCE
+						: AggregateSupportImpl.INSTANCE;
+	}
+
+	public static AggregateSupport forTiDB(Dialect dialect) {
+		return JSON_WITH_UUID_INSTANCE;
+	}
+
+	public static AggregateSupport forMariaDB(Dialect dialect) {
+		return LONGTEXT_INSTANCE;
 	}
 
 	@Override
@@ -92,11 +112,20 @@ public class MySQLAggregateSupport extends AggregateSupportImpl {
 						);
 					case UUID:
 						if ( column.getJdbcMapping().getJdbcType().isBinary() ) {
+							if ( uuidFunctions ) {
 								return template.replace(
 										placeholder,
-									"unhex(replace(json_unquote(" + queryExpression( aggregateParentReadExpression, columnExpression ) + "),'-',''))"
+										"uuid_to_bin(json_unquote(" + queryExpression( aggregateParentReadExpression, columnExpression ) + "))"
 								);
 							}
+							else {
+								return template.replace(
+										placeholder,
+										"unhex(replace(json_unquote(" + queryExpression( aggregateParentReadExpression,
+												columnExpression ) + "),'-',''))"
+								);
+							}
+						}
 						// Fall-through intended
 					default:
 						return template.replace(
@@ -142,7 +171,7 @@ public class MySQLAggregateSupport extends AggregateSupportImpl {
 		}
 	}
 
-	private static String jsonCustomWriteExpression(String customWriteExpression, JdbcMapping jdbcMapping) {
+	private String jsonCustomWriteExpression(String customWriteExpression, JdbcMapping jdbcMapping) {
 		final int sqlTypeCode = jdbcMapping.getJdbcType().getDefaultSqlTypeCode();
 		switch ( sqlTypeCode ) {
 			case BINARY:
@@ -159,8 +188,13 @@ public class MySQLAggregateSupport extends AggregateSupportImpl {
 				return "date_format(" + customWriteExpression + ",'%Y-%m-%dT%T.%fZ')";
 			case UUID:
 				if ( jdbcMapping.getJdbcType().isBinary() ) {
+					if ( uuidFunctions ) {
+						return "bin_to_uuid(" + customWriteExpression + ")";
+					}
+					else {
 						return "regexp_replace(lower(hex(" + customWriteExpression + ")),'^(.{8})(.{4})(.{4})(.{4})(.{12})$','$1-$2-$3-$4-$5')";
 					}
+				}
 				// Fall-through intended
 			default:
 				return customWriteExpression;

hibernate-core/src/test/java/org/hibernate/orm/test/instant/InstantWithNormalizedTest.java

@@ -10,6 +10,7 @@ import org.hibernate.annotations.JdbcTypeCode;
 import org.hibernate.cfg.AvailableSettings;
 import org.hibernate.cfg.JdbcSettings;
 import org.hibernate.dialect.MySQLDialect;
+import org.hibernate.dialect.TiDBDialect;
 import org.hibernate.testing.orm.junit.EntityManagerFactoryScope;
 import org.hibernate.testing.orm.junit.Jpa;
 import org.hibernate.testing.orm.junit.Setting;
@@ -31,6 +32,7 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 				{@Setting(name = AvailableSettings.TIMEZONE_DEFAULT_STORAGE, value = "NORMALIZE"),
 				@Setting(name = JdbcSettings.JDBC_TIME_ZONE, value = "+01:00")})
 @SkipForDialect(dialectClass = MySQLDialect.class, reason = "MySQL hangs dropping the table")
+@SkipForDialect(dialectClass = TiDBDialect.class, reason = "Values stored in timestamp DDL type columns get the JDBC time zone offset subtracted")
 public class InstantWithNormalizedTest {
 	@Test
 	public void test(EntityManagerFactoryScope scope) {