使用临时表存储IN子句中的值列表,然后进行连接查询。 参考链接 SQL Server WHERE Clause SQL Server IN Operator SQL Server IF...ELSE Statement 通过以上信息,你应该能够更好地理解 SQL Server 中IF条件和WHERE子句中的IN运算符,并能够解决相关的性能问题。
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 语句影响的行数的信息。...SET NOCOUNT 为 ON 时,不返回计数(表示受 Transact-SQ...
{ sql_statement | statement_block } [ ELSE { 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...
2.<set>:常用于<update>更新语句中,替代 sql中的“set”关键字,特别是在联合<if>进行判断是,可以有效方式当某个参数为空或者不合法是错误的更新到数据库中 <update id="updateByPrimaryKeySelective" parameterType="pojo.Orderitem" >update orderitem<set > <iftest="productId != null" >product_id= #{pr...
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. ...
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...
Error: Can't update table 'table2' in stored function/trigger because it is already used by statement which invoked this stored function/trigger. 1. 2. 这个错误的意思就是,在执行修改的时候触发一个触发器,而触发器中会执行另外一个UPDATE语句,会接着触发另一个触发器… 从而形成循环触发,因此执行失...
This article explores the useful function SQL IF statement in SQL Server. Introduction In real life, we make decisions based on the conditions. For example, look at the following conditions. If I get a performance bonus this year, I will go for international vacation or else I’ll take a ...
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
CREATE PROCEDURE UPDATE_SAL (IN empNum CHAR(6), INOUT rating SMALLINT) LANGUAGE SQL BEGIN IF rating = 1 THEN UPDATE employee SET salary = salary * 1.10, bonus = 1000 WHERE empno = empNum; ELSEIF rating = 2 THEN UPDATE employee