SELECT IF(1 < 2, 'true', 'false'); -- 输出结果为 'true' 2. SQL Server 在SQL Server中,IF语句的语法如下: IF conditionstatements;ELSEstatements; 示例: DECLARE @num INT = 10;IF @num > 5PRINT 'Number is greater than 5.';ELSEPRINT 'Number is less than or equal to 5.'; 3. Orac...
ELSE语句是可选的,如果省略了ELSE语句,PL/SQL会隐含增加一个ELSE语句: ELSE RAISE CASE_NOT_FOUND; 注意:即使省略了ELSE语句,PL/SQL也会执行ELSE语句,程序执行时也会收到一个异常。 简单CASE语句声明语法如下: CASE selector_variable WHEN criterion1 TH EN criterion1_statements; WHEN criterion2 THEN criterion...
SQL存储过程中的IF-ELSE语句允许您基于条件来选择不同的操作。在SQL Server中,IF-ELSE语句的语法如下: ``` IF condition BEGIN -- Statements to execute when the condition is TRUE END ELSE BEGIN -- Statements to execute when the condition is FALSE END ``` 这是一个基本的IF-ELSE语句结构,其中“...
1. 什么是 IF ELSE 语句 IF ELSE语句允许我们根据条件的真或假来流转程序的执行路径。它的基本形式如下所示: IF<condition>THEN<statements_if_true>ELSE<statements_if_false>ENDIF; 1. 2. 3. 4. 5. 在SQL 中,条件表达式通常是布尔类型的结果,即要么为真(TRUE),要么为假(FALSE)。 2. 在 MySQL 中的 ...
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...
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...
是一种在数据库中创建新列的操作,它使用ifelse语句集来根据条件组合两个已有的列的值。 ifelse语句集是一种条件语句,它根据给定的条件判断来执行不同的操作。在SQL中,ifelse语句集通常使用CASE语句来实现。CASE语句可以根据条件选择不同的值或执行不同的操作。 使用Create column通过SQL中的ifelse语句集组合两...
statements inside the body of if are skipped from execution. Working of if...else Statement Example 2: if...else statement // Check whether an integer is odd or even #include <stdio.h> int main() { int number; printf("Enter an integer: "); scanf("%d", &number); // True if ...
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....
D. Use nested IF...ELSE statementsThe 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 העתק DECLARE @Number INT; SET @Number = 50; IF @Number > 100 PRINT 'The ...