In the T-SQL scripting language, you can use the SQL CASE statement to evaluate a condition and return one or more result expressions. This SQL Tutorial will teach you when and how you can use CASE in T-SQL sta
Mysql中的条件语句在我们对数据进行转换的时候比较有用,这样就不需要创建中转表。...= "" IF ELSE 流程控制语句在mysql存储过程中的用法: IF search_condition THEN statement_list [ELSEIF search_condition...[ELSE statement_list] END IF IF作为一条语句,在END IF后需要加上分号“;”以表示语句结束,其他语...
CASE With ELSE ACASEstatement can have an optionalELSEclause. TheELSEclause is executed if none of the conditions in theCASEstatement is matched. Syntax SELECTcustomer_id, first_name,CASEWHENcondition1THENresult1WHENcondition2THENresult2-- Add more WHEN conditions and results as neededELSEelse_resu...
case语句与case表达式是plsql流程控制的重要组成部分,尽管其使用方法较为简单,但容易混淆。...本文将描述case语句与case表达式并给出演示以便于更好理解两者的异同及使用时的注意事项。...WHEN EXPRESSION N THEN STATEMENT N; ELSE STATEMENT N+1; END CASE; --简单的case语句是指SELECTOR中得到的值或结果与EXPR...
This SQL Server tutorial explains how to use the SQL Server (Transact-SQL) CASE statement with syntax and examples. In SQL Server (Transact-SQL), the CASE statement has the functionality of an IF-THEN-ELSE statement. You can use the CASE statement within
if/then else case statement query in SQL ServerThis creates start and end columns by doing a ...
When the IF THEN statement has no ELSE clause and the condition is not met, PL/SQL does nothing instead raising an error. Simple CASE statement example The following example compares single value (c_grade) with many possible values ‘A’, ‘B’,’C’,’D’, and ‘F’: DECLARE c_...
Once the condition and expression are matched, it returns the expression mentioned in THEN clause. We have following syntax for a case statement in SQL with a simple expression 1 2 3 4 5 6 SELECT CASE Expression When expression1 Then Result1 When expression2 Then Result2 ... ELSE ...
ELSE UPDATE department SET deptname = 'D3'; END CASE END 以下是带有搜索式 CASE 语句 WHEN 子句的 CASE 语句的示例: CREATE PROCEDURE UPDATE_DEPT (IN p_workdept) LANGUAGE SQL BEGIN DECLARE v_workdept CHAR(3); SET v_workdept = p_workdept; ...
Simple Case Statement CASE [input_expression] WHEN when_expression THEN when_true_result_expression [...n] [ELSE else_result_expression] END Search Case Statement CASE WHEN Boolean_expression THEN when_true_result_expression [...n] [ELSE else_result_expression] END ...