SQL语句大全中的sql语句备忘录—sql日常使用指北 9、说明:创建视图:create view viewname as select statement 删除视图:drop view viewname10、说明:几个简单的基本的sql语句选择:select...RecID 是自增长字段, 写一个SQL语句, 找出表的第31到第40个记录。 ...Transact-SQL
In SQL Server there is anIF…ELSE control flow statement. However, it cannot be used inside a SELECT statement. The closest of IF…THEN operation which can be used in SELECT statements is CASE expression or the IIF function. Let us see how to use CASE and IIF using an example. For thi...
你可以在 IF 语句中使用 SELECT 查询,但需要注意查询的结果必须能够转换为布尔值,以便进行条件判断。 基础概念 IF 语句在MySQL中用于根据条件执行不同的SQL语句块。其基本语法如下: 代码语言:txt 复制 IF search_condition THEN statement_list [ELSEIF search_condition THEN statement_list] ... [ELSE statemen...
this statement is equivalent to nested IF...THEN...ELSE...IF...THEN statements, but only one END IF is needed. The following example uses an IF...THEN...ELSIF...ELSE statement to count the number of employees by compensation, in steps of $25,000. ...
IF Boolean_expression { sql_statement | statement_block } [ ELSE { sql_statement | statement_block } ]Boolean_expression: A boolean expression that returns TRUE or FALSE. If the Boolean expression contains a SELECT statement then it should be enclosed in parentheses. ...
{ sql_statement | statement_block } ] 参数说明: Boolean_expression返回True或False的表达式。如果布尔表达式包含SELECT语句,则SELECT语句必须用括号括起来 { sql_statement | statement_block }使用语句块定义的任何有效的Transact-SQL语句或语句分组。要定义语句块(批处理),请使用流语言关键字BEGIN和END 组合。尽...
We can understand SQL IF Statement using the following flow chart. The condition in SQL IF Statement should return a Boolean value to evaluate We can specify a Select statement as well in a Boolean expression, but it should enclose in parentheses ...
create procedure p(inout score double)beginset score := score * 0.5;end;set @score = 198;call p(@score);select @score; case 介绍 case结构及作用,和我们之前的流程控制函数很类似。有两种语法格式: 语法一: /* 含义: 当case_value的值为 when_value1时,执行statement_list1,当值为 when_value2...
This SQL Server tutorial explains how to use the IF...ELSE statement in SQL Server (Transact-SQL) with syntax and examples. In SQL Server, the IF...ELSE statement is used to execute code when a condition is TRUE, or execute different code if the conditio
Use the IF statement for control flow, which is unlike theIIf (MDX)function and theCASE Statement (MDX)that can only be used to return values or objects. Examples In the following example, the scope is restricted to the Country level of the Customers Geography hierarchy in the Customers dime...