CONNECT BY 的应用

ORACLE向表中插入１到20，按照往常，第一反应会想到写个小程序来完成此功能。

 

SQL> create table tc(id int);

Table created.

SQL> insert into tc SELECT LEVEL AS ID FROM dual CONNECT BY LEVEL <= 20;　

20 rows created.

SQL> commit;

Commit complete.

SQL> select * from tc;

        ID
----------
         1
         2
         3
         4
         5
         6
         7
         8
         9
        10
        11

        ID
----------
        12
        13
        14
        15
        16
        17
        18
        19
        20

20 rows selected

.