The key to using simple CASE statements effectively is understanding how to compare an expression to fixed values.The expression in a simple CASE statement can be a column name, a function, or any valid SQL expression. The values in the WHEN clauses are the fixed values against which we wan...
The SQLCASEstatement evaluates a list of conditions and adds a column with values based on the condition. For example, -- add a new column 'order_volume' in the Orders table-- and flag any order greater than 10000 as 'Large Order'-- and smaller than 10000 as 'Small Order'SELECT*,CASE...
我想使用CASE语句根据某些条件选择输入的数据SQL中的CASE WHEN使用 Case具有两种格式。简单Case函数和Case搜...
if语句 在查询中使用if,语法如下: if('表达式','真值','假值'). 比如在数据中库存储的性别字段为1或者0,查询时想获取男,女...case语句 当两种选择是可以使用if,有多种选择的时候就需要case语句了...比如在上例子中,我们存储了一些不希望暴露性别的用户,存储的值为3.此时想要查询可以: select s.name ...
CASE selector WHEN selector_value_1 THEN statements_1 WHEN selector_value_1 THEN statement_2 ... ELSE else_statements END CASE; Code language: PostgreSQL SQL dialect and PL/pgSQL (pgsql) Let’s examine the syntax of the simple CASE statement in detail: 1) selector The selector is an...
SQL: CASE Statement 1.CASE 写法如下: CASE WHEN condition1 THEN result1 WHEN condition2 THEN result2 WHEN conditionN THEN resultN ELSE result END; 解释:1)先匹配第一条,不匹配的话继续第二条,如此循环,
SQL---CASE WHEN条件表达式(conditional statement) CASE表达式是用来判断条件的,条件成立时返回某个值,条件不成立时返回另一个值。 语法: CASEWHENComparsionConditionTHENresultWHENComparsionConditionTHENresultELSEotherEND (注:各分支返回的数据类型需一致。)...
SELECT CASE WHEN department IN ('IT', 'Finance') THEN 'Group A' ELSE 'Group B' END AS group_name, COUNT(*) AS employee_count FROM employees GROUP BY group_name; In this query, theCASEstatement checks if the "department" value is in the list ('IT', 'Finance'). If it matches, ...
You should wrap your SQL query with brackets and also use "0/1" for checkbox field comparison. So, your formula should look like this: CASE WHEN [@field:Agree]=0 AND [@field:Term]="Disc1" THEN (SELECT Price FROM Products WHERE Model=target.[@field:Model] AND Color=target.[@field...
我们可以用下面的coalesce语句来表示case-statement: t2.date = coalesce(t1.date, t3date) 它看起来干净多了,但在功能上仍然与case语句相同。 请注意,如果您没有从t2和t3投射任何值,那么进行where date in (select date from t2) or date in (select date from t3)运算会更快。