T-SQL：在WHERE中使用{fn NOW（）}

I was reviewing some SQL queries and I saw a select statement that looked like this

我正在审查一些SQL查询，我看到了一个看起来像这样的select语句

SELECT *
FROM dbo.mytable
WHERE (dbo.mytable.[Date] < { fn NOW() })

What is the purpose of using a WHERE statement like this?

使用像这样的WHERE语句的目的是什么？

Wouldn't be easier to use a simple GETDATE()?

使用简单的GETDATE（）会不会更容易？

1 个解决方案

#1

http://www.sqlservercentral.com/Forums/Topic183904-8-1.aspx

GETDATE() is a T-SQL specific function which returns the current system date and time. The SQL standard equivalent is CURRENT_TIMESTAMP which is applicable in T-SQL as well. The {fn Now()} is an ODBC canonical function which can be used in T-SQL since the OLE DB provider for SQL Server supports them. There are no notable performance difference between these though. You can also use canonical format like :

GETDATE（）是一个特定于T-SQL的函数，它返回当前系统的日期和时间。 SQL标准等价物是CURRENT_TIMESTAMP，它也适用于T-SQL。 {fn Now（）}是一个ODBC规范函数，可以在T-SQL中使用，因为SQL Server的OLE DB提供程序支持它们。但是这些之间没有明显的性能差异。您还可以使用规范格式，如：

SELECT {fn CURRENT_TIMESTAMP()} AS "date & time",
       {fn CURRENT_DATE()} AS "date only",
       {fn CURRENT_TIME()} AS "time only" ;

#1

http://www.sqlservercentral.com/Forums/Topic183904-8-1.aspx

SELECT {fn CURRENT_TIMESTAMP()} AS "date & time",
       {fn CURRENT_DATE()} AS "date only",
       {fn CURRENT_TIME()} AS "time only" ;

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T-SQL：在WHERE中使用{fn NOW（）}

1 个解决方案

#1

#1

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