Correctly consider aliases when disambiguating ORDER BY columns

Author: JanJakes

tests/WP_SQLite_Driver_Translation_Tests.php

@@ -1398,6 +1398,12 @@ public function testSelectOrderByAmbiguousColumnResolution(): void {
 			'SELECT t1.name, t2.name FROM t1 JOIN t2 ON t2.id = t1.id ORDER BY name DESC'
 		);
 
+		// When the SELECT item list is ambiguous with an alias, the ORDER BY column is not disambiguated (like in MySQL).
+		$this->assertQuery(
+			"SELECT `t1`.`name` , 'test' AS `name` FROM `t1` JOIN `t2` ON `t2`.`id` = `t1`.`id` ORDER BY `name` DESC",
+			"SELECT t1.name, 'test' AS `name` FROM t1 JOIN t2 ON t2.id = t1.id ORDER BY name DESC"
+		);
+
 		// When the ORDER BY item uses an alias, there is no ambiguity.
 		$this->assertQuery(
 			'SELECT `t1`.`name` AS `t1_name` FROM `t1` JOIN `t2` ON `t2`.`t1_id` = `t1`.`id` ORDER BY `t1_name` DESC',

wp-includes/sqlite-ast/class-wp-sqlite-driver.php

@@ -2947,7 +2947,8 @@ private function translate_query_expression( WP_Parser_Node $node ): string {
 			$select_item_list = $node->get_first_descendant_node( 'selectItemList' );
 
 			// Get a list of column references used in the SELECT item list.
-			$select_column_refs = array();
+			$select_column_refs  = array();
+			$select_alias_values = array();
 			foreach ( $select_item_list->get_child_nodes() as $select_item ) {
 				/*
 				 * [GRAMMAR]
@@ -2961,7 +2962,9 @@ private function translate_query_expression( WP_Parser_Node $node ): string {
 				}
 
 				// Skip when a SELECT item alias is used (as per MySQL behavior).
-				if ( $select_item->has_child_node( 'selectAlias' ) ) {
+				$alias = $select_item->get_first_child_node( 'selectAlias' );
+				if ( $alias ) {
+					$select_alias_values[] = $this->translate( $alias->get_first_child_node() );
 					continue;
 				}
 
@@ -3004,27 +3007,31 @@ private function translate_query_expression( WP_Parser_Node $node ): string {
 				// Support also parenthesized ORDER BY column references (e.g. "(id)").
 				$order_expr = $this->unnest_parenthesized_expression( $order_expr );
 
-				// Consider only simple and parenthesized column references.
+				// Consider only simple and parenthesized order column references;
+				// skip when the ORDER BY item value matches a SELECT item alias.
 				$order_expr_value   = $this->translate( $order_expr );
 				$order_column_value = $this->translate( $order_column_ref );
+				$matches_alias      = in_array( $order_expr_value, $select_alias_values, true );
+				if ( $order_expr_value !== $order_column_value || $matches_alias ) {
+					$disambiguated_order_list[] = $this->translate( $order_item );
+					continue;
+				}
 
 				// Look for select items that match the column reference.
 				$select_item_matches = array();
-				if ( $order_expr_value === $order_column_value ) {
-					foreach ( $select_column_refs as $select_column_ref ) {
-						// Skip non-qualified column references in the SELECT item.
-						$dot_identifiers = $select_column_ref->get_descendant_nodes( 'dotIdentifier' );
-						if ( count( $dot_identifiers ) === 0 ) {
-							continue;
-						}
+				foreach ( $select_column_refs as $select_column_ref ) {
+					// Skip non-qualified column references in the SELECT item.
+					$dot_identifiers = $select_column_ref->get_descendant_nodes( 'dotIdentifier' );
+					if ( count( $dot_identifiers ) === 0 ) {
+						continue;
+					}
 
-						// Compare only the column names (last "dotIdentifier" node).
-						$last_dot_identifier = end( $dot_identifiers );
-						$select_column_name  = $this->translate( $last_dot_identifier->get_first_child_node() );
-						$order_column_name   = $this->translate( $order_column_ref );
-						if ( $select_column_name === $order_column_name ) {
-							$select_item_matches[] = $this->translate( $select_column_ref );
-						}
+					// Compare only the column names (last "dotIdentifier" node).
+					$last_dot_identifier = end( $dot_identifiers );
+					$select_column_name  = $this->translate( $last_dot_identifier->get_first_child_node() );
+					$order_column_name   = $this->translate( $order_column_ref );
+					if ( $select_column_name === $order_column_name ) {
+						$select_item_matches[] = $this->translate( $select_column_ref );
 					}
 				}