在SQL语句中使用IF或CASE with multiple条件的作用是根据不同的条件执行不同的操作或返回不同的结果。这些条件可以是基于列的值、函数的结果、逻辑表达式等。 使用IF语句可以根据条件执行不同的操作。IF语句的基本语法如下: 代码语言:txt 复制 IF condition THEN statement1; ELSE statement2; END IF; 其中,conditio...
Case Statement returning multiple values CASE statement returns "Invalid Column Name" Error Case statement that increments variable with 1 is giving error Case Statement using Divide CASE Statement when not null , else if Help Case statement with Between in Where Clause Case statement with Date Compa...
CASE With Multiple Conditions It is also possible to stack multiple conditions inside a singleCASEclause. Syntax SELECTcolumn1, column2, ...CASEWHENcondition1THENresult1WHENcondition2THENresult2-- Add more WHEN conditions and results as neededENDASalias_nameFROMtable_name; We can add as manyWHEN...
不然会导致转换无效. SELECT id, case WHEN cast(`status` AS SIGNED) < 45 THEN '1' WHEN cast(...
Evaluates a list of conditions and returns one of multiple possible result expressions. TheCASEexpression has two formats: The simpleCASEexpression compares an expression to a set of simple expressions to determine the result. The searchedCASEexpression evaluates a set of Boolean expressions to determin...
Evaluates a list of conditions and returns one of multiple possible result expressions. TheCASEexpression has two formats: The simpleCASEexpression compares an expression to a set of simple expressions to determine the result. The searchedCASEexpression evaluates a set of Boolean expressions to determin...
小结:对于该 case, 索引效果[org_code,trade_date_time] > [trade_date_time, org_code]>[trade_date_time]。实际业务场景中,检索条件中 trade_date_time 基本上肯定会出现,但 org_code 却不一定,故索引的设计还需要结合实际业务需求。 优化Order by ...
CASE expression. When this happens SQL Server will return the result expression associated with the first WHEN expression that evaluates to true. Therefore the order of your WHEN clauses will control what result you get returned from your CASE expression if multiple WHEN clauses evaluate to TRUE....
CASE Statement TheCASEstatement selects a sequence of statements to execute. To select the sequence, theCASEstatement uses a selector (an expression whose value is used to select one of several alternatives) or, in the searchedCASEstatement, multiple search conditions. ...
5)case表达式 第6部分经典业务问题 这部分要学习SQL高级功能窗口函数,然后用来解决工作里的经典业务问题,比如: 排名问题、topN问题、复购分析、累计问题、高级比较问题等 第7部分:实战项目 这部分可以通过实战项目来加强练习SQL,把学过的SQL应用起来,比如我做的这个用户行为分析实战项目,手把手教你如何做实战。 上面内...