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mysql iF ElsE

MySql 查询不支持if else流程控制,但是可以使用case函数来实现相同流程控制功能。 下面举例供参考: 根据考生分数判定是否合格 select sid,grade, case when grade

不知你用的是什么查询分析器。 我记得 select count(*) into @cnt from table1 where map_id = 114 and `type` = 400 ; if @cnt > 0 then update table1 set `count` = 25 where map_id = 114 and `type` = 400; else insert table1 (map_id,`co...

你可以试一下先输入select 'printSEQ' from 'policyexpress' where policyno='000000600326 ' into '@cnt'; 再输入if '@cnt' ='' then update policyexpress set printSEQ = '212121212' where policyno = '000000600326'; end if

你可以试一下先输入select 'printSEQ' from 'policyexpress' where policyno='000000600326 ' into '@cnt'; 再输入if '@cnt' ='' then update policyexpress set printSEQ = '212121212' where policyno = '000000600326'; end if

select name from tb where name='li' union all select top 1 '没有这名字' from tb where not exists(select 1 from tb where name='li')

select SUM(CASE WHEN channel_type=1 AND check_status=6 THEN 1 ELSE 0 END)FROM tougao_record WHERE accept_company_id=100

mysql> DELIMITER //mysql> CREATE PROCEDURE TestIfElse -> ( -> p_val INT -> ) -> BEGIN -> IF (p_val = 1) THEN -> SELECT '1' AS A; -> ELSEIF (p_val = 2) THEN -> SELECT '2' AS A; -> ELSE -> SELECT 'other' AS A; -> END IF; -> END//...

mysql> DELIMITER // mysql> CREATE PROCEDURE TestIfElse -> ( -> p_val INT -> ) -> BEGIN -> IF (p_val = 1) THEN -> SELECT '1' AS A; -> ELSEIF (p_val = 2) THEN -> SELECT '2' AS A; -> ELSE -> SELECT 'other' AS A; -> END IF; -> END/...

select中的IF函数是if(A=B,0,other) IF语句 if a=b then 0; else 1; end if;

不同的数据库中,存储过程中if else 语句写法有一些差别。 如果是SQLServer数据库,存储过程的if, else语句可以这样写: if a>bBegin print 'a'EndElse if a 100 THEN dbms_output.put_line( '100+' );ELSIF testvalue = 100 THEN dbms_output.p...

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