SQL:行列转换(一)
下面的内容将呈现一个简单的行列转换的例子,行列转换的方式很多,不止一种。
eg.
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SQL> select * from ginfo; GID GNAME ---------- ---------------------------------------- 1 Natural 2 Human SQL> select * from uinfo; USER_ID USERNAME GID ---------- ------------- ---------- 1 Alice 2 2 Baby Angela 1 3 Dolly 2 SQL> SQL> col "user list" for a40 SQL> run 1* select u.gid,wm_concat(u.username) "user list" from uinfo u,ginfo g where u.gid=g.gid group by u.gid GID user list ---------- ---------------------------------------- 1 Baby Angela 2 Alice,Dolly SQL> |
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Ending。[……]