Mysql将3张表合并为一个表

表A，表B，表C，如下图：

实现结果：

SQL语句：

select concat('P',cast(p.provinceID as char)) as id, p.name as text,0 as pid,'false' as leaf from ts_province p union
select concat('C',cast(c.cityID as char)) as id, c.name as text,concat('P',cast(c.father as char)) as pid,'false' as leaf from ts_city c union
select concat('A',cast(a.areaID as char)) as id, a.name as text,concat('C',cast(a.father as char)) as pid,'false' as leaf from ts_area a