Python SQL-两个左连接

我有一些关于SQL for Python的问题,希望您能帮助我-我正在尝试从wordpress/woomerce检索一些数据。

我的代码:

    cursor.execute("
    SELECT t1.ID, t1.post_date, t2.meta_value AS first_name, t3.meta_value AS last_name
    FROM test_posts t1 
    LEFT JOIN test_postmeta t2 
    ON t1.ID = t2.post_id 
    WHERE t2.meta_key = '_billing_first_name' and t2.post_id = t1.ID 
    LEFT JOIN test_postmeta t3 
    ON t1.ID = t3.post_id 
    WHERE t3.meta_key = '_billing_last_name' and t3.post_id = t1.ID 
    GROUP BY t1.ID 
    ORDER BY t1.post_date DESC LIMIT 20")

我得到以下错误:

    mysql.connector.errors.ProgrammingError: 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'LEFT JOIN test_postmeta t3 ON t1.ID = t3.post_id WHERE t3.meta_key = '_billing' at line 1

我做错什么了?

提前谢谢。