1# 卧龙 发表于 2006-10-13 00:36

Oracle 9i 数据库WITH查询语法小议

　　Oracle9i新增了WITH语法功能，可以将查询中的子查询命名，放到SELECT语句的最前面。

　　下面看一个简单的例子:
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代码:
SQL> WITH
2 SEG AS (SELECT SEGMENT_NAME, SUM(BYTES)/1024 K FROM USER_SEGMENTS GROUP BY SEGMENT_NAME),
3 OBJ AS (SELECT OBJECT_NAME, OBJECT_TYPE FROM USER_OBJECTS)
4 SELECT O.OBJECT_NAME, OBJECT_TYPE, NVL(S.K, 0) SIZE_K
5 FROM OBJ O, SEG S
6 WHERE O.OBJECT_NAME = S.SEGMENT_NAME (+)
7 ;
OBJECT_NAME OBJECT_TYPE SIZE_K
DAIJC_TEST TABLE 128
P_TEST PROCEDURE 0
IND_DAIJC_TEST_C1 INDEX 128