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select CONVERT(varchar, getdate(), 120 )
2004-09-12 11:06:08
select replace(replace(replace(CONVERT(varchar, getdate(), 120 ),\'-\',\'\'),\' \',\'\'),\':\',\'\')
20040912110608
select CONVERT(varchar(12) , getdate(), 111 )
2004/09/12
select CONVERT(varchar(12) , getdate(), 112 )
20040912
select CONVERT(varchar(12) , getdate(), 102 )
2004.09.12
select CONVERT(varchar(12) , getdate(), 101 )
09/12/2004
select CONVERT(varchar(12) , getdate(), 103 )
12/09/2004
select CONVERT(varchar(12) , getdate(), 104 )
12.09.2004
select CONVERT(varchar(12) , getdate(), 105 )
12-09-2004
select CONVERT(varchar(12) , getdate(), 106 )
12 09 2004
select CONVERT(varchar(12) , getdate(), 107 )
09 12, 2004
select CONVERT(varchar(12) , getdate(), 108 )
11:06:08
select CONVERT(varchar(12) , getdate(), 109 )
09 12 2004 1
select CONVERT(varchar(12) , getdate(), 110 )
09-12-2004
select CONVERT(varchar(12) , getdate(), 113 )
12 09 2004 1
select CONVERT(varchar(12) , getdate(), 114 )
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