2) Case:a) If the value of the <search condition> of some <searched when clause> in a <c...
The CASE statement goes through conditions and returns a value when the first condition is met (like an IF-THEN-ELSE statement). So, once a condition is true, it will stop reading and return the result. If no conditions are true, it returns the value in the ELSEclause. If there is no...
To use CASE, your WHERE clause would have to be: Code: where o.adddte between case When d = 2 then date1 when d = 3 then date3 else date5 end and case When d = 2 then date2 when d = 3 then date4 else date6 end The other problem is the invalid expressions in your SQL li...
由于mio_log表的mio_date、plnmio_date字段,以及freph_a01_fromtask3表的in_force_date字段上均有索引,可先通过单个mio_date、in_force_date、plnmio_date索引取出增量时间段数据,在增量数据上进行不同表、字段的比对。SELECT (CASE WHEN in_force_date IS NOT NULL THEN ( CASE WHEN mio_date >= in...
3.关于IF-THEN-ELSE的其他实现 3.1 DECODE() 函数 selectdecode(sex,'M','Male','F','Female','Unknown')fromemployees; 1. 2. 貌似只有Oracle提供该函数,而且不支持ANSI SQL,语法上也没CASE WHEN清晰,个人不推荐使用。 3.2 在WHERE中特殊实现
WHEN MyCol1 <> 'Value1' And MyCol2 = 'Active' Then 'Value1' In the scenario where MyCol1 <> Value1 and MyCol2 <> 'Active' then no update would occur and the original value would remain intact. View 2 RepliesView Related Transact SQL :: Where ...
Acaseexpression produces a scalar value, while you want to evaluate conditions. You can use ...
这个是一个在Where条件中添加case when的需求,在链接(https://stackoverflow.com/questions/206484/sql-switch-case-in-where-clause)中学习到,这个确实可以做的,但更易于接受是通过OR做处理,其可以理解成: dayofmonth(curdate())=1 and 查询条件=上个月; ...
SQL中的 CASE 类似编程语言里的 if-then-else 语句,用做逻辑判断。可以用于SELECT语句中,也可以用在WHERE,GROUP BY 和 ORDER BY 子句;可以单独使用,也可以和聚合函数结合使用。 语法如下: CASE WHEN condition1 THEN result1 [WHEN condition2 THEN result2] ...
SQL - Where Clause SQL - Top Clause SQL - Distinct Clause SQL - Order By Clause SQL - Group By Clause SQL - Having Clause SQL - AND & OR SQL - BOOLEAN (BIT) Operator SQL - LIKE Operator SQL - IN Operator SQL - ANY, ALL Operators SQL - EXISTS Operator SQL - CASE SQL - NOT Op...