HHH-18225 Fix for Informix syntax error in DISTINCT clause before SKIP clause

Author: VladoKuruc

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

@@ -10,11 +10,11 @@
 
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.query.sqm.ComparisonOperator;
+import org.hibernate.sql.ast.Clause;
 import org.hibernate.sql.ast.SqlAstNodeRenderingMode;
 import org.hibernate.sql.ast.spi.AbstractSqlAstTranslator;
 import org.hibernate.sql.ast.spi.SqlSelection;
 import org.hibernate.sql.ast.tree.Statement;
-import org.hibernate.sql.ast.tree.cte.CteStatement;
 import org.hibernate.sql.ast.tree.expression.Expression;
 import org.hibernate.sql.ast.tree.expression.Literal;
 import org.hibernate.sql.ast.tree.expression.SqlTuple;
@@ -35,6 +35,21 @@ public InformixSqlAstTranslator(SessionFactoryImplementor sessionFactory, Statem
 		super( sessionFactory, statement );
 	}
 
+	@Override
+	public void visitSelectClause(SelectClause selectClause) {
+		getClauseStack().push( Clause.SELECT );
+
+		try {
+			appendSql( "select " );
+			visitSqlSelections( selectClause );
+			renderVirtualSelections( selectClause );
+		}
+		finally {
+			getClauseStack().pop();
+		}
+
+	}
+
 	@Override
 	protected void visitSqlSelections(SelectClause selectClause) {
 		if ( supportsSkipFirstClause() ) {
@@ -43,6 +58,9 @@ protected void visitSqlSelections(SelectClause selectClause) {
 		else {
 			renderFirstClause( (QuerySpec) getQueryPartStack().getCurrent() );
 		}
+		if ( selectClause.isDistinct() ) {
+			appendSql( "distinct " );
+		}
 		super.visitSqlSelections( selectClause );
 	}