HHH-18497 Add special xmlquery and xmlexists functions for DB2 10.5

Author: beikov

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

@@ -446,8 +446,14 @@ public void initializeFunctionRegistry(FunctionContributions functionContributio
 		functionFactory.xmlforest();
 		functionFactory.xmlconcat();
 		functionFactory.xmlpi();
-		functionFactory.xmlquery_db2();
-		functionFactory.xmlexists();
+		if ( getDB2Version().isSameOrAfter( 11 ) ) {
+			functionFactory.xmlquery_db2();
+			functionFactory.xmlexists();
+		}
+		else {
+			functionFactory.xmlquery_db2_legacy();
+			functionFactory.xmlexists_db2_legacy();
+		}
 		functionFactory.xmlagg();
 	}
 

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

@@ -431,8 +431,14 @@ public void initializeFunctionRegistry(FunctionContributions functionContributio
 		functionFactory.xmlforest();
 		functionFactory.xmlconcat();
 		functionFactory.xmlpi();
-		functionFactory.xmlquery_db2();
-		functionFactory.xmlexists();
+		if ( getDB2Version().isSameOrAfter( 11 ) ) {
+			functionFactory.xmlquery_db2();
+			functionFactory.xmlexists();
+		}
+		else {
+			functionFactory.xmlquery_db2_legacy();
+			functionFactory.xmlexists_db2_legacy();
+		}
 		functionFactory.xmlagg();
 	}
 

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

@@ -157,6 +157,8 @@
 import org.hibernate.dialect.function.xml.H2XmlElementFunction;
 import org.hibernate.dialect.function.xml.H2XmlForestFunction;
 import org.hibernate.dialect.function.xml.H2XmlPiFunction;
+import org.hibernate.dialect.function.xml.LegacyDB2XmlExistsFunction;
+import org.hibernate.dialect.function.xml.LegacyDB2XmlQueryFunction;
 import org.hibernate.dialect.function.xml.PostgreSQLXmlQueryFunction;
 import org.hibernate.dialect.function.xml.SQLServerXmlAggFunction;
 import org.hibernate.dialect.function.xml.SQLServerXmlConcatFunction;
@@ -4237,6 +4239,13 @@ public void xmlquery_db2() {
 		functionRegistry.register( "xmlquery", new XmlQueryFunction( false, typeConfiguration ) );
 	}
 
+	/**
+	 * DB2 10.5 xmlquery() function
+	 */
+	public void xmlquery_db2_legacy() {
+		functionRegistry.register( "xmlquery", new LegacyDB2XmlQueryFunction( typeConfiguration ) );
+	}
+
 	/**
 	 * PostgreSQL xmlquery() function
 	 */
@@ -4265,6 +4274,13 @@ public void xmlexists_sqlserver() {
 		functionRegistry.register( "xmlexists", new SQLServerXmlExistsFunction( typeConfiguration ) );
 	}
 
+	/**
+	 * DB2 10.5 xmlexists() function
+	 */
+	public void xmlexists_db2_legacy() {
+		functionRegistry.register( "xmlexists", new LegacyDB2XmlExistsFunction( typeConfiguration ) );
+	}
+
 	/**
 	 * Standard xmlagg() function
 	 */

hibernate-core/src/main/java/org/hibernate/dialect/function/xml/LegacyDB2XmlExistsFunction.java

@@ -0,0 +1,47 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.dialect.function.xml;
+
+import java.util.List;
+
+import org.hibernate.dialect.function.json.ExpressionTypeHelper;
+import org.hibernate.query.ReturnableType;
+import org.hibernate.sql.ast.SqlAstTranslator;
+import org.hibernate.sql.ast.spi.SqlAppender;
+import org.hibernate.sql.ast.tree.SqlAstNode;
+import org.hibernate.sql.ast.tree.expression.Expression;
+import org.hibernate.type.spi.TypeConfiguration;
+
+/**
+ * DB2 10.5 xmlexists function.
+ */
+public class LegacyDB2XmlExistsFunction extends XmlExistsFunction {
+
+	public LegacyDB2XmlExistsFunction(TypeConfiguration typeConfiguration) {
+		super( typeConfiguration );
+	}
+
+	@Override
+	public void render(
+			SqlAppender sqlAppender,
+			List<? extends SqlAstNode> sqlAstArguments,
+			ReturnableType<?> returnType,
+			SqlAstTranslator<?> walker) {
+		final String xquery = walker.getLiteralValue( (Expression) sqlAstArguments.get( 0 ) );
+		final Expression xmlDocument = (Expression) sqlAstArguments.get( 1 );
+		final boolean needsCast = !ExpressionTypeHelper.isXml( xmlDocument );
+		sqlAppender.appendSql( "xmlexists(" );
+		sqlAppender.appendSingleQuoteEscapedString( "$d" + xquery );
+		sqlAppender.appendSql( " passing " );
+		if ( needsCast ) {
+			sqlAppender.appendSql( "xmlparse(document " );
+		}
+		sqlAstArguments.get( 1 ).accept( walker );
+		if ( needsCast ) {
+			sqlAppender.appendSql( ')' );
+		}
+		sqlAppender.appendSql( " as \"d\")" );
+	}
+}

hibernate-core/src/main/java/org/hibernate/dialect/function/xml/LegacyDB2XmlQueryFunction.java

@@ -0,0 +1,47 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.dialect.function.xml;
+
+import java.util.List;
+
+import org.hibernate.dialect.function.json.ExpressionTypeHelper;
+import org.hibernate.query.ReturnableType;
+import org.hibernate.sql.ast.SqlAstTranslator;
+import org.hibernate.sql.ast.spi.SqlAppender;
+import org.hibernate.sql.ast.tree.SqlAstNode;
+import org.hibernate.sql.ast.tree.expression.Expression;
+import org.hibernate.type.spi.TypeConfiguration;
+
+/**
+ * DB2 10.5 xmlquery function.
+ */
+public class LegacyDB2XmlQueryFunction extends XmlQueryFunction {
+
+	public LegacyDB2XmlQueryFunction(TypeConfiguration typeConfiguration) {
+		super( false, typeConfiguration );
+	}
+
+	@Override
+	public void render(
+			SqlAppender sqlAppender,
+			List<? extends SqlAstNode> sqlAstArguments,
+			ReturnableType<?> returnType,
+			SqlAstTranslator<?> walker) {
+		final String xquery = walker.getLiteralValue( (Expression) sqlAstArguments.get( 0 ) );
+		final Expression xmlDocument = (Expression) sqlAstArguments.get( 1 );
+		final boolean needsCast = !ExpressionTypeHelper.isXml( xmlDocument );
+		sqlAppender.appendSql( "xmlquery(" );
+		sqlAppender.appendSingleQuoteEscapedString( "$d" + xquery );
+		sqlAppender.appendSql( " passing " );
+		if ( needsCast ) {
+			sqlAppender.appendSql( "xmlparse(document " );
+		}
+		sqlAstArguments.get( 1 ).accept( walker );
+		if ( needsCast ) {
+			sqlAppender.appendSql( ')' );
+		}
+		sqlAppender.appendSql( " as \"d\")" );
+	}
+}