虽然标准的SQL没有直接的 IF ELSE 语句(像某些编程语言中的那样),但大多数数据库系统提供了实现类似功能的方法。以下是几种常见的方法: 1. 使用 CASE 表达式 CASE 表达式是标准SQL的一部分,可以用于在SELECT、INSERT、UPDATE和DELETE语句中实现条件逻辑。 语法: CASE WHEN condition1 THEN
包含if和else问题的pl/sql过程如果lname不为零，那么myu sql变量永远不会被赋值。如果文字值要更改，请...
今天,写存储过程时写成了:if...then...else if...else...end if.能编译通过,但是有问题,后来实在是找不到问题怀疑写错了这个语句,后来在网上查了一下,结果不是else if 而是elsif.改过来后就正常了。 Oracle/PLSQL: IF-THEN-ELSE Statement There are three different syntaxes for these types of statemen...
2、IF - ELSIF - ELSE 多条件分支使用“IF - ELSIF - ELSE”进行判断,语法上比简单的 IF - ELSE 多了一小段: IF { condition_1 } THEN { PLSQL_BLOCKS_1 } ELSIF [ condition_2 ] THEN { PLSQL_BLOCKS_2 } ELSIF [ condition_3 ] THEN { PLSQL_BLOCKS_3 } ... ELSE { PLSQL_BL...
PLSQL: IF-THEN-ELSE There are three different syntaxes for these types of statements. Syntax #1: IF-THEN IF condition THEN {...statements...} END IF; Syntax #2: IF-THEN-ELSE IF condition THEN {...statements...} ELSE {...statements...}...
Syntax (IF-THEN-ELSE) The syntax for IF-THEN-ELSE in Oracle/PLSQL is: IF condition THEN {...statements to execute when condition is TRUE...} ELSE {...statements to execute when condition is FALSE...} END IF; You use the IF-THEN-ELSE syntax, when you want to execute one set of...
8 shell if elif else 2019-12-19 18:59 −if 语句的判断条件,从本质上讲,判断的就是命令的退出状态。 语句语句格式同一行书写注意点用例1用例2 if 语句 if conditionthen statement(s)fi if condition; then statement(s... 声声慢43 0 590
CASE 表达式在 SQL 中用于条件逻辑,它允许你根据一个或多个条件返回不同的值。基本语法如下: 代码语言:txt 复制 CASE WHEN condition1 THEN result1 WHEN condition2 THEN result2 ... ELSE resultN END 应用场景 假设你有两个表:orders 和customers。你想根据订单的类型来决定如何连接这两个表。例如,对于...
2) PL/pgSQL if-then-else statement The if...then...else statement executes the statements in the if branch if the condition evaluates to true; otherwise, it executes the statements in the else branch. Here’s the syntax of the if...then...else statement: if condition then statements;...
The basic syntax of theIF-ELSIF-ELSEconditional statement in PL/pgSQL is as follows: IF condition1 THEN -- code block executed if condition1 is true ELSIF condition2 THEN -- code block executed if condition2 is true ... ELSE -- code block executed if none of the conditions are true ...