关于SQL中按日期查询的小问题

[pangmao]

在SQL中按日期查询时，
我知道SELECT * FROM picture WHERE PostTime>'2003-03-12';
但是我取得的比较时间都是字符串，如何将字符串s替换'2003-03-12'
最后的形式类似于 SELECT * FROM picture WHERE PostTime> s

[francsescoli]

DECLARE @s varchar(20)
SET @s = '2003-03-12'
SELECT * FROM picture WHERE PostTime> @s

[pangmao]

不好意思，我是这样写的：
string t1 = "2003-03-12";
cmd="DECLARE @s varchar(10) SET @s = 't1' select * from picture where PostTime >@s";
结果报错，请指点一下

[awinder]

string t1 = "2003-03-12";
cmd="select * from picture where PostTime >'"+t1+"'";

[小鸿叔]

using System;
using System.Data;
using System.Data.SqlClient;
using System.Data.SqlTypes;

sql="select * from picture where PostTime >@s";
SqlCommand cmd=new SqlCommand(sql);
cmd.Parameters.Add("@s",SqlDbType.VarChar,10).Value="2003-03-12";

[mmens]

cmd="DECLARE @s varchar(10) SET @s = 't1' select * from picture where PostTime >@s";

改成：

cmd="DECLARE @s varchar(10) SET @s = '" + t1 + "' select * from picture where PostTime >@s";

[pangmao]

感激不尽！

[sorrow_man]

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