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)