AccessLeftOuterJoin关联多个表

Access 支持三表或三表以上的 join 操作，但是要加括号，一层一层 JOIN 下去 例子： 1、SELECT * from XXas a left outer join YY as b on a.URL=b.URL 2、SELECT * from (XXas a left outer join YY as b on a.URL=b.URL) left outer join ZZ as c on c.URL

Access 支持三表或三表以上的 join 操作，但是要加括号，一层一层 JOIN 下去

例子：
1、SELECT * from XXas a left outer join YY as b on a.URL=b.URL

2、SELECT * from (XXas a left outer join YY as b on a.URL=b.URL) left outer join ZZ as c on c.URL=a.URL

3、SELECT * into all_ from ((((XX as a left outer join YY as b on a.URL=b.URL)

left outer join ZZ as c on c.URL=a.URL)
left outer join MM as d on d.URL=a.URL)
left outer join NN as e on e.URL=a.URL)