HHH-9707 - Nulls first behavior on SQLServer database

(cherry picked from commit 6f37a2e)

Conflicts:
	hibernate-core/src/main/java/org/hibernate/dialect/SQLServer2012Dialect.java

HHH-9707 - Nulls first behavior on SQLServer database
(cherry picked from commit 046426b)

Conflicts:
	hibernate-core/src/main/java/org/hibernate/dialect/SQLServer2012Dialect.java

Author: maeda

hibernate-core/src/main/java/org/hibernate/dialect/SQLServer2008Dialect.java

@@ -8,6 +8,7 @@
 
 import java.sql.Types;
 
+import org.hibernate.NullPrecedence;
 import org.hibernate.dialect.function.NoArgSQLFunction;
 import org.hibernate.type.StandardBasicTypes;
 
@@ -29,4 +30,26 @@ public SQLServer2008Dialect() {
 				"current_timestamp", new NoArgSQLFunction( "current_timestamp", StandardBasicTypes.TIMESTAMP, false )
 		);
 	}
+	
+	@Override
+	public String renderOrderByElement(String expression, String collation, String order, NullPrecedence nulls) {
+		final StringBuilder orderByElement = new StringBuilder();
+
+		if ( nulls != null && !NullPrecedence.NONE.equals( nulls ) ) {
+			// Workaround for NULLS FIRST / LAST support.
+			orderByElement.append( "case when " ).append( expression ).append( " is null then " );
+			if ( NullPrecedence.FIRST.equals( nulls ) ) {
+				orderByElement.append( "0 else 1" );
+			}
+			else {
+				orderByElement.append( "1 else 0" );
+			}
+			orderByElement.append( " end, " );
+		}
+
+		// Nulls precedence has already been handled so passing NONE value.
+		orderByElement.append( super.renderOrderByElement( expression, collation, order, NullPrecedence.NONE ) );
+
+		return orderByElement.toString();
+	}
 }

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

@@ -203,5 +203,6 @@ protected SqlTypeDescriptor getSqlTypeDescriptorOverride(int sqlCode) {
 	public int getInExpressionCountLimit() {
 		return PARAM_LIST_SIZE_LIMIT;
 	}
+	
 }
 

hibernate-core/src/test/java/org/hibernate/test/annotations/onetomany/OrderByTest.java

@@ -26,6 +26,9 @@
 import org.hibernate.dialect.H2Dialect;
 import org.hibernate.dialect.MySQLDialect;
 import org.hibernate.dialect.Oracle8iDialect;
+import org.hibernate.dialect.SQLServer2008Dialect;
+import org.hibernate.dialect.SQLServer2012Dialect;
+import org.hibernate.dialect.SQLServerDialect;
 import org.hibernate.engine.spi.SessionImplementor;
 import org.hibernate.persister.collection.CollectionPersister;
 import org.hibernate.persister.collection.QueryableCollection;
@@ -80,10 +83,10 @@ public void testOrderByOnIdClassProperties() throws Exception {
 
 	@Test
 	@TestForIssue(jiraKey = "HHH-465")
-	@RequiresDialect(value = { H2Dialect.class, MySQLDialect.class },
+	@RequiresDialect(value = { H2Dialect.class, MySQLDialect.class, SQLServer2008Dialect.class },
 			comment = "By default H2 places NULL values first, so testing 'NULLS LAST' expression. " +
-					"For MySQL testing overridden Dialect#renderOrderByElement(String, String, String, NullPrecedence) method. " +
-					"MySQL does not support NULLS FIRST / LAST syntax at the moment, so transforming the expression to 'CASE WHEN ...'.")
+					"For MySQL and SQL Server 2008 testing overridden Dialect#renderOrderByElement(String, String, String, NullPrecedence) method. " +
+					"MySQL and SQLServer 2008 does not support NULLS FIRST / LAST syntax at the moment, so transforming the expression to 'CASE WHEN ...'.")
 	public void testAnnotationNullsFirstLast() {
 		Session session = openSession();
 
@@ -139,10 +142,10 @@ public void testAnnotationNullsFirstLast() {
 
 	@Test
 	@TestForIssue(jiraKey = "HHH-465")
-	@RequiresDialect(value = { H2Dialect.class, MySQLDialect.class },
+	@RequiresDialect(value = { H2Dialect.class, MySQLDialect.class, SQLServer2008Dialect.class },
 			comment = "By default H2 places NULL values first, so testing 'NULLS LAST' expression. " +
-					"For MySQL testing overridden Dialect#renderOrderByElement(String, String, String, NullPrecedence) method. " +
-					"MySQL does not support NULLS FIRST / LAST syntax at the moment, so transforming the expression to 'CASE WHEN ...'.")
+					"For MySQL and SQL Server 2008 testing overridden Dialect#renderOrderByElement(String, String, String, NullPrecedence) method. " +
+					"MySQL and SQL Server 2008 does not support NULLS FIRST / LAST syntax at the moment, so transforming the expression to 'CASE WHEN ...'.")
 	public void testCriteriaNullsFirstLast() {
 		Session session = openSession();
 
@@ -177,10 +180,10 @@ public void testCriteriaNullsFirstLast() {
 
 	@Test
 	@TestForIssue(jiraKey = "HHH-465")
-	@RequiresDialect(value = { H2Dialect.class, MySQLDialect.class },
+	@RequiresDialect(value = { H2Dialect.class, MySQLDialect.class, SQLServer2008Dialect.class },
 			comment = "By default H2 places NULL values first, so testing 'NULLS LAST' expression. " +
-					"For MySQL testing overridden Dialect#renderOrderByElement(String, String, String, NullPrecedence) method. " +
-					"MySQL does not support NULLS FIRST / LAST syntax at the moment, so transforming the expression to 'CASE WHEN ...'.")
+					"For MySQL and SQL Server 2008 testing overridden Dialect#renderOrderByElement(String, String, String, NullPrecedence) method. " +
+					"MySQL and SQL Server 2008 does not support NULLS FIRST / LAST syntax at the moment, so transforming the expression to 'CASE WHEN ...'.")
 	public void testNullsFirstLastSpawnMultipleColumns() {
 		Session session = openSession();
 
@@ -226,10 +229,10 @@ public void testNullsFirstLastSpawnMultipleColumns() {
 
 	@Test
 	@TestForIssue(jiraKey = "HHH-465")
-	@RequiresDialect(value = { H2Dialect.class, MySQLDialect.class },
+	@RequiresDialect(value = { H2Dialect.class, MySQLDialect.class, SQLServer2008Dialect.class },
 			comment = "By default H2 places NULL values first, so testing 'NULLS LAST' expression. " +
-					"For MySQL testing overridden Dialect#renderOrderByElement(String, String, String, NullPrecedence) method. " +
-					"MySQL does not support NULLS FIRST / LAST syntax at the moment, so transforming the expression to 'CASE WHEN ...'.")
+					"For MySQL and SQL Server 2008 testing overridden Dialect#renderOrderByElement(String, String, String, NullPrecedence) method. " +
+					"MySQL and SQL Server 2008 does not support NULLS FIRST / LAST syntax at the moment, so transforming the expression to 'CASE WHEN ...'.")
 	public void testHqlNullsFirstLast() {
 		Session session = openSession();