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WITH TEMP_TAB1 AS
(
SELECT 1 ID , 'MINGMING' NAME ,0 SCORE FROM DUAL UNION ALL
SELECT 9 ID , 'MINGMING' NAME ,20 SCORE FROM DUAL UNION ALL
SELECT 2 ID , 'HUAHUA' NAME , 80 SCORE FROM DUAL UNION ALL
SELECT 3 ID , 'NIUNIU' NAME, 90 SCORE FROM DUAL UNION ALL
SELECT 4 ID , 'MEI' NAME ,70 SCORE FROM DUAL UNION ALL
SELECT 5 ID , 'YOU' NAME, 40 SCORE FROM DUAL
) ,TEMP_TAB2 AS
(
SELECT 1 ID , 'REN' NAME , 20 SCORE FROM DUAL UNION ALL
SELECT 3 ID , 'NIUNIU' NAME ,30 SCORE FROM DUAL UNION ALL
SELECT 4 ID , 'RURU' NAME ,60 SCORE FROM DUAL UNION ALL
SELECT 5 ID , 'HONGHONG' NAME ,0 SCORE FROM DUAL
) SELECT *
FROM TEMP_TAB1 A
inner JOIN TEMP_TAB2 B
ON A.ID = B.ID
and b.score <> 0
--and 10/a.score = 0.25
where 10/b.score = 0.5
SQL Select语句完整的执行顺序:
1、from子句组装来自不同数据源的数据;
2、where子句基于指定的条件对记录行进行筛选;
3、group by子句将数据划分为多个分组;
4、使用聚集函数进行计算;
5、使用having子句筛选分组;
6、计算所有的表达式;
7、select 的字段;
8、使用order by对结果集进行排序。