(T-SQL) 是與 SQL Server 溝通的核心.凡存取 SQL Server 執行個體 01 的所有應用程式,不論其使用者介面為何(例如,我們一般透過 .NET,VB, ASP 寫的應用程式,SQL Server 自己的管理介面 SQL Server Management Studio, 02 sqlcmd…等),都是藉由傳遞 T-SQL 陳述式給伺服器,以要求 SQL Server 完成某 項任務...
1DECLARE@MyDateDATETIME;2DECLARE@DateAfter7DaysDATETIME;3SET@MyDate=GETDATE();4SET@DateAfter7Days=DATEADD(day,7,@MyDate) ;--计算距今7天之后的日期5PRINT@DateAfter7Days;6PRINTDATEDIFF(day,@MyDate,@DateAfter7Days) ;--7,差7天7--第一个参数都是时间单位,可选的有:year,month,day,week,hour,...
SET TRANSACTION --定义当前事务数据访问特征 --程序化SQL DECLARE --为查询设定游标 EXPLAN --为查询描述数据访问计划 OPEN --检索查询结果打开一个游标 FETCH --检索一行查询结果 CLOSE --关闭游标 PREPARE --为动态执行准备SQL 语句 EXECUTE --动态地执行SQL 语句 DESCRIBE --描述准备好的查询 ---局部变量 d...
when (@@datefirst + datepart(weekday,min(dateadd(day,0,datediff(day,0,dateadd(day,d.i,dateadd(month,m.i,dateadd(year,datediff(year,0,@),0)))+1)) % 7 = 3 and datediff(month,min(dateadd(day,0,datediff(day,0,dateadd(day,d.i,dateadd(month,m.i,dateadd(year,datediff(year,0,@),0...
SET DATEFIRST 3; -- Because Wednesday is now considered the first day of the week, -- DATEPART now shows that 1999-1-1 (a Friday) is the third day of the -- week. The following DATEPART function should return a value of 3. SELECT CAST('1999-1-1' AS datetime2) AS SelectDate...
DATEDIFF Week - First day of week query datepart(dw, date) Datetime - Out of range Datetime Value DateTime - Time round off to starting of day DateTime filter is not returning correct results Datetime in Indian Standard TimeZone (IST) DateTime Interval in "DD HH:MM:SS" Dat...
在T-SQL中,用户变量以@符号开头,用于声明为特定的数据类型。可以使用SET或者SELECT语句给变量赋值。以下的例子用于将一个int类型的变量@MyNumber传递给SQRT()函数: DECLARE @MyNumber int SET @MyNumber=144 SELECT SQRT(@MyNumber) 结果是12,即144的平方根。 用SET给变量赋值 以下例子使用另一个int型的变量@...
SQL Performance, T-SQL, T-SQL Anti-patterns Leave a comment This week I happened to assist with an internal application where there was a performance issue with a specific query. One of my observations with that query was that it was doing self-joins in order to determine the latest iter...
Transact-SQL, known as T-SQL for short, is a set of programming extensions that enhances the capabilities of Structured Query Language (SQL). Read more.
2008 R2 使用 GetSystemTimeAsFileTime() Windows API 来获取日期和时间值。精确程度取决于运行 SQL ...