IF语句有三种使用方式:IF、IF...ELSE...、IF...ELIF...。这三种方式根据实际的情况灵活选择。 (1)IF 语法结构: IF condition THEN statement; END IF; 1. 2. (2) IF...ELSE...结构语法结构: IF condition THEN statements ; ELSE statements; END IF; 1. 2. 3. (3)IF...ELIF...结构 IF co...
在MySQL 存储过程中使用 IF-ELSE 语句的基本语法如下: IFconditionTHEN-- Statements to execute if condition is trueELSE-- Statements to execute if condition is falseENDIF; 1. 2. 3. 4. 5. 交叉使用 IF ELSE 语句 交叉使用是指在一个 IF 块中使用嵌套的 IF 语句。然而,这并不是一个 MySQL 局限性...
It executes the ELSE statement and prints the message for it. In this case, we have two SQL IF statements. The second IF statement evaluates to false, therefore, it executes corresponding ELSE statement 它执行ELSE语句并为其打印消息。 在这种情况下,我们有两个SQL IF语句。 第二条IF语句的计算结...
PostgreSQL offers several decision-making statements such asIF,IF-THEN-ELSE,IF-THEN-ELSIF, etc. All these decision-driven statements are used to control the flow of the SQL statements based on specific criteria. In Postgres, theIFandIF-THEN-ELSEstatements evaluate only one condition; however, the...
1、PL/pgSQL 代码块结构 [ <> ] [ DECLARE declarations ] BEGIN statements; ... END [ label ]; 结构说明: label 是一个可选的代码块标签,可以用于 EXIT 语句退出指定的代码块,或者限定变量的名称; DECLARE 是一个可选的声明部分,用于定义变量; BEGIN 和...
IF ELSE THEN是一种条件语句,用于在触发器中根据特定条件执行不同的逻辑。它的语法如下: 代码语言:txt 复制 IF condition THEN statements; ELSE statements; END IF; 其中,condition是一个逻辑表达式,statements是需要执行的SQL语句。 触发器语法和IF ELSE THEN可以结合使用,以实现更复杂的逻辑。例如,可以在触发器...
D. Use nested IF...ELSE statements The following example shows how anIF...ELSEstatement can be nested inside another. Set the@Numbervariable to5,50, and500, to test each statement. SQL DECLARE@NumberINT;SET@Number=50; IF @Number > 100 PRINT 'The number is large.'; ELSEBEGINIF@Number...
else if (x < 0) - checks if x is less than 0 Here, both the test conditions are False. Hence, the statement inside the body of else is executed. Nested if...else Statements in R You can have nested if...else statements inside if...else blocks in R. This is called nested if....
MySQL IF ELSEIF ELSE语句 如果要基于多个表达式有条件地执行语句,则使用IF ELSEIF ELSE语句如下: IFexpressionTHENstatements; ELSEIF elseif-expressionTHENelseif-statements; ...ELSEelse-statements;ENDIF; 如果表达式(expression)求值为TRUE,则IF分支中的语句(statements)将执行;如果表达式求值为FALSE,则如果elseif...
D. Use nested IF...ELSE statements The following example shows how an IF...ELSE statement can be nested inside another. Set the @Number variable to 5, 50, and 500, to test each statement. SQL Копіювати DECLARE @Number INT; SET @Number = 50; IF @Number > 100 PRINT ...