SQL常遇到的小问题整理

2015.10.30

今天写了个统计男女比例的sql：

SELECT "SUM"(CASE WHEN p.PSRD_GENDER='M' then 1 else 0 end) as male,
"SUM"(CASE WHEN p.PSRD_GENDER='F' then 1 else 0 end) as female
FROM VIEW_VPS_TA_PSR as p;

结果一直报错，[Err] ORA-00933: SQL command not properly ended，结果后来发现是结尾部分有问题，

修改后：

SELECT "SUM"(CASE WHEN PSRD_GENDER='M' then 1 else 0 end) as male,
"SUM"(CASE WHEN PSRD_GENDER='F' then 1 else 0 end) as female
FROM VIEW_VPS_TA_PSR ;

总结：sql结尾如果没有其他条件，则as用起来不妥，会导致结尾没有正确结束的错误。