CONVERT(data_type,expression[,style]) 说明:
此样式一般在时间类型(datetime,smalldatetime)与字符串类型(nchar,nvarchar,char,varchar)
相互转换的时候才用到. 例子:
SELECT CONVERT(varchar(),getdate(),) now
结果为
now
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// ///////////////////////////////////////////////////////////////////////////////////// style数字在转换时间时的含义如下 -------------------------------------------------------------------------------------------------
Style(2位表示年份) | Style(4位表示年份) | 输入输出格式
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- | or | mon dd yyyy hh:miAM(或PM)
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| | mm/dd/yy
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| | yy-mm-dd
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| | dd/mm/yy
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| | dd-mm-yy
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| | dd-mm-yy
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| | dd mon yy
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| | mon dd,yy
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| | hh:mm:ss
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- | or | mon dd yyyy hh:mi:ss:mmmmAM(或PM)
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| | mm-dd-yy
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| | yy/mm/dd
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| | yymmdd
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- | or | dd mon yyyy hh:mi:ss:mmm(24小时制)
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| | hh:mi:ss:mmm(24小时制)
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- | or | yyyy-mm-dd hh:mi:ss(24小时制)
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- | or | yyyy-mm-dd hh:mi:ss:mmm(24小时制) 例如当前时间为：-- :: 我要取其中的：-- select convert(char(),'2005-9-12 13:20:00',) CAST ( expression AS data_type )
将某种数据类型的表达式显式转换为另一种数据类型
declare @a int
cast(@a as varchar())--从而连接动态语句