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)