Refactor CRUD::delete method to support advanced DELETE queries (#25)

The current implementation relies on `wpdb::delete`, which supports only simple `where x = y` conditions. It's not only incomplete but also dangerous because `Where::$comparisonOperator` and `Where::$logicalOperator` are just ignored, so the result is unpredictable. The following change provides a way to use existing QueryBuilder functionality to generate DELETE SQL. The documentation describes some restrictions.

Author: shvlv

.github/workflows/tests-php.yml

@@ -28,13 +28,12 @@ jobs:
       # Prepare our composer cache directory
       # ------------------------------------------------------------------------------
       - name: Get Composer Cache Directory
-        id: get-composer-cache-dir
-        run: |
-          echo "::set-output name=dir::$(composer config cache-files-dir)"
-      - uses: actions/cache@v2
         id: composer-cache
+        run: |
+          echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
+      - uses: actions/cache@v4
         with:
-          path: ${{ steps.get-composer-cache-dir.outputs.dir }}
+          path: ${{ steps.composer-cache.outputs.dir }}
           key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
           restore-keys: |
             ${{ runner.os }}-composer-

README.md

@@ -874,12 +874,74 @@ DB::table('table_name')
 
 The `QueryBuilder::delete` method may be used to delete records from the table.
 
+Unlike WordPress's `$wpdb->delete()` method, this implementation generates and executes a DELETE SQL statement directly, which allows for advanced features like ORDER BY and LIMIT.
+
+#### Basic delete with WHERE
+
 ```php
 DB::table('posts')
     ->where('post_author', 1)
     ->delete();
 ```
 
+#### Delete with LIMIT
+
+Limit the number of rows to delete:
+
+```php
+// Delete only the first 10 draft posts
+DB::table('posts')
+    ->where('post_status', 'draft')
+    ->limit(10)
+    ->delete();
+```
+
+#### Delete with ORDER BY and LIMIT
+
+Control which rows are deleted when using LIMIT:
+
+```php
+// Delete the 100 oldest posts in trash
+DB::table('posts')
+    ->where('post_status', 'trash')
+    ->orderBy('post_date', 'ASC')
+    ->limit(100)
+    ->delete();
+```
+
+#### Delete with LIKE patterns
+
+Use pattern matching to delete rows:
+
+```php
+// Delete all posts with titles starting with "Draft:"
+DB::table('posts')
+    ->whereLike('post_title', 'Draft:%')
+    ->delete();
+```
+
+#### Delete with complex WHERE conditions
+
+Combine multiple WHERE clauses for precise deletion:
+
+```php
+// Delete auto-draft pages with IDs between 1 and 1000
+DB::table('posts')
+    ->where('post_type', 'page')
+    ->where('post_status', 'auto-draft')
+    ->whereBetween('ID', 1, 1000)
+    ->delete();
+
+// Delete posts using whereIn
+DB::table('posts')
+    ->whereIn('ID', [5, 10, 15, 20])
+    ->delete();
+```
+
+**Important restrictions:**
+- Table aliases in the FROM clause may not be supported on older database versions (MySQL < 8.0.24, MariaDB < 11.6). Avoid using table aliases when calling `delete()`.
+- JOINs are not supported in DELETE statements with this implementation.
+
 
 ### Get
 

src/DB/QueryBuilder/Concerns/CRUD.php

@@ -75,18 +75,56 @@ public function upsert( $data, $match = [], $format = null ) {
 	}
 
 	/**
+	 * Delete rows from the database.
+	 *
+	 * Unlike WordPress's $wpdb->delete() method, this implementation generates and executes
+	 * a DELETE SQL statement directly, which allows for advanced features like ORDER BY and LIMIT.
+	 *
+	 * Supports:
+	 * - WHERE clauses (including whereLike, whereIn, whereBetween, etc.)
+	 * - ORDER BY for controlling which rows are deleted first
+	 * - LIMIT to restrict the number of rows deleted
+	 * - Complex WHERE conditions (AND, OR, nested queries)
+	 *
+	 * Usage examples:
+	 * ```php
+	 * // Simple delete with WHERE
+	 * DB::table('posts')->where('post_status', 'draft')->delete();
+	 *
+	 * // Delete with LIMIT (delete only 10 rows)
+	 * DB::table('posts')->where('post_type', 'temp')->limit(10)->delete();
+	 *
+	 * // Delete oldest posts first using ORDER BY and LIMIT
+	 * DB::table('posts')
+	 *     ->where('post_status', 'trash')
+	 *     ->orderBy('post_date', 'ASC')
+	 *     ->limit(100)
+	 *     ->delete();
+	 *
+	 * // Delete with LIKE pattern
+	 * DB::table('posts')->whereLike('post_title', 'Draft:%')->delete();
+	 *
+	 * // Delete with multiple conditions
+	 * DB::table('posts')
+	 *     ->where('post_type', 'page')
+	 *     ->where('post_status', 'auto-draft')
+	 *     ->whereBetween('ID', 1, 1000)
+	 *     ->delete();
+	 * ```
+	 *
+	 * Restrictions:
+	 * - Table aliases in the FROM clause may not be supported on older database versions
+	 *   (MySQL < 8.0.24, MariaDB < 11.6). Avoid using table aliases with delete().
+	 * - JOINs are not supported in DELETE statements with this implementation
+	 *
 	 * @since 1.0.0
 	 *
-	 * @return false|int
+	 * @return false|int Number of rows deleted, or false on error.
 	 *
-	 * @see https://developer.wordpress.org/reference/classes/wpdb/delete/
+	 * @see QueryBuilder::deleteSQL() for the SQL generation logic
 	 */
 	public function delete() {
-		return DB::delete(
-			$this->getTable(),
-			$this->getWhere(),
-			null
-		);
+		return DB::query( $this->deleteSQL() );
 	}
 
 	/**

src/DB/QueryBuilder/QueryBuilder.php

@@ -53,7 +53,38 @@ public function getSQL() {
 			$this->getUnionSQL()
 		);
 
-		// Trim double spaces added by DB::prepare
+		return $this->buildSQL($sql);
+	}
+
+	/**
+	 * Generate the SQL for a DELETE query. Only the FROM, WHERE, ORDER BY, and LIMIT clauses are included.
+	 * RETURNING is not supported.
+	 * Note that aliases are supported only on MySQL >= 8.0.24 and MariaDB >= 11.6.
+	 *
+	 * @see https://mariadb.com/docs/server/reference/sql-statements/data-manipulation/changing-deleting-data/delete
+	 * @see https://dev.mysql.com/doc/refman/8.4/en/delete.html
+	 *
+	 * @return string DELETE query.
+	 */
+	public function deleteSQL() {
+		$sql = array_merge(
+			$this->getFromSQL(),
+			$this->getWhereSQL(),
+			$this->getOrderBySQL(),
+			$this->getLimitSQL()
+		);
+
+		return 'DELETE ' . $this->buildSQL($sql);
+	}
+
+	/**
+	 * Build the SQL query from the given parts.
+	 *
+	 * @param array $sql The SQL query parts.
+	 *
+	 * @return string SQL query.
+	 */
+	private function buildSQL( $sql ) {
 		return str_replace(
 			[ '   ', '  ' ],
 			' ',