In the following SQL IF Statement, it evaluates the expression, and if the condition is true, then it executes the statement mentioned in IF block otherwise statements within ELSE clause is executed. 在下面SQL IF语句中,它计算表达式,如果条件为true,则执行IF块中提到的语句,否则将执行ELSE子句中的语...
IF THEN in SQL SELECT Statement I recently came across the CASE WHEN statement work Similar to IF statement into SQL SELECT , Maybe you’ll find it useful. Create table called Student using SQL Query: CREATE TABLE [dbo].[Student]( [StudentID] [int] NULL, [Marks] [float] NULL ) Inse...
END关键词表明PL/SQL体的结束 2.SELECT INTO STATEMENT 将select查询的结果存入到变量中,可以同时将多个列存储多个变量中,必须有一条 记录,否则抛出异常(如果没有记录抛出NO_DATA_FOUND) 例子: BEGIN SELECT col1,col2 into 变量1,变量2 FROM typestruct where xxx; EXCEPTION WHEN NO_DATA_FOUND THEN xxxx; ...
IF...THEN...ELSE statements specify an alternative set of statements that should be executed if the condition evaluates to FALSE. In the following example, the previous example is modified so that an IF...THEN...ELSE statement is used to display the textNon-commissionif an employee does not...
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;...
{ sql_statement | statement_block } 使用语句块定义的任何 Transact-SQL 语句或语句分组。 除非使用了语句块,IF否则或ELSE条件只能影响一个 Transact-SQL 语句的性能。 若要定义语句块,请使用流控制关键字BEGIN和END。 注解 IF...ELSE可以在批处理、存储过程和即席查询中使用构造。 在存储过程中使用此构造时,通...
与上述语句不同的是,该语句中的 WHEN 语句将被逐个执行,直到某个 search_condition 表达式为真,则执行对应 THEN 关键字后面的 statement_list 语句。如果没有条件匹配,ELSE 子句里的语句被执行。 这里介绍的 CASE 语句与“控制流程函数”里描述的 SQL CASE 表达式的 CASE 语句有轻微的不同。这里的 CASE 语句不...
Using IF in PL/pgSQL The IF statement in PL/pgSQL allows developers to execute conditional operations within a procedural block. Syntax: DO $$ BEGIN IF condition THEN -- Statements to execute if condition is true ELSIF other_condition THEN ...
Transact-SQL 語法慣例 語法 syntaxsql IFboolean_expression{sql_statement|statement_block} [ELSE{sql_statement|statement_block} ] 引數 boolean_expression 傳回 或FALSE的TRUE表達式。如果boolean_expression包含SELECT語句,SELECT語句必須以括弧括住。 使用語句區塊所定義的任何有效 Transact-SQL 語句或語句群組。 若...
IF语句可以有THEN、ELSE和ELSEIF子句,并以END IF结束。如果给定的search_condition计算结果为true,则执行相应的THEN或ELSEIF子句statement_list。如果没有匹配的search_condition,则执行ELSE子句statement_list。每个statement_list由一个或多个SQL语句组成;不允许statement_list为空。IF ... END IF 块与存储程序中使用...