Database: Find the correct table names in `DELETE` queries with table aliases

Previously, `wpdb::get_table_from_query()` would not find the correct table name in the query `DELETE a FROM table a`, due to not recognising the table alias immediately after the `DELETE` as correct syntax.

Fixes #37660.



git-svn-id: https://develop.svn.wordpress.org/trunk@38507 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/wp-db.php

@@ -3029,7 +3029,7 @@ class wpdb {
 				. '|INSERT(?:\s+LOW_PRIORITY|\s+DELAYED|\s+HIGH_PRIORITY)?(?:\s+IGNORE)?(?:\s+INTO)?'
 				. '|REPLACE(?:\s+LOW_PRIORITY|\s+DELAYED)?(?:\s+INTO)?'
 				. '|UPDATE(?:\s+LOW_PRIORITY)?(?:\s+IGNORE)?'
-				. '|DELETE(?:\s+LOW_PRIORITY|\s+QUICK|\s+IGNORE)*(?:\s+FROM)?'
+				. '|DELETE(?:\s+LOW_PRIORITY|\s+QUICK|\s+IGNORE)*(?:.+?FROM)?'
 				. ')\s+((?:[0-9a-zA-Z$_.`-]|[\xC2-\xDF][\x80-\xBF])+)/is', $query, $maybe ) ) {
 			return str_replace( '`', '', $maybe[1] );
 		}

tests/phpunit/tests/db.php

@@ -562,6 +562,8 @@ class Tests_DB extends WP_UnitTestCase {
 			"DELETE QUICK $table",
 			"DELETE IGNORE $table",
 			"DELETE LOW_PRIORITY FROM $table",
+			"DELETE a FROM $table a",
+			"DELETE `a` FROM $table a",
 
 			// STATUS
 			"SHOW TABLE STATUS LIKE '$table'",