sql语句查询到的值如何赋值给一个变量

[kerry030401]

现在我想把我用sql语句查询到的值赋值给一个变量如int，请问如何实现？
例如语句为“select A from table where years=2000 and months=2”
这样在数据库里查到的是A这个列的一个值，我想把这个值现在赋值给一个int变量，请问如何实现？

[popcode]

把查询结果绑到DataTable，然后在DataTable里取出来

[fuda_1985]

declare @n int
select top 1 (@n=A) from table where years=2000 and months=2
这样写安全点！~

[ReyZhang]

[Quote=引用 1 楼 jacklygoodluck 的回复:]
declare @n int
select @n=A from table where years=2000 and months=2
[/Quote]

[jiang_jiajia10]

sqlstr = "select A from table where years=2000 and months=2" ; 
            BaseService bc = new BaseService(); 
DataTable dt = bc.ExecuteDataTable(sqlstr ); 
foreach (DataRow dr in dt.Rows) 
{ 
int n = dr["A"].ToString(); 

} 

BaseService bc = new BaseService();
写一些数据库读取的代码，因为这是我自己定义的方法。

[kerry030401]

[Quote=引用 1 楼 jacklygoodluck 的回复:]
declare @n int
select @n=A from table where years=2000 and months=2
[/Quote]

请问这个是写在存储过程里面还是...？我不太清楚 对存储过程不是很了解～
并且我的years和months也是不定的，根据dropdownlist的选择来变的～

[pdsnet]

[Quote=引用 1 楼 jacklygoodluck 的回复:]
declare @n int
select @n=A from table where years=2000 and months=2
[/Quote]

[柳泉青云]

SqlDataReader dr=db.getReader(“select A from table where years=2000 and months=2");
if(dr.Read())
{
if(dr["A"].ToString().Trim()!=null)
{
int intA=int.part(dr["A"].ToString());
}
}

[ljqingas]

[Quote=引用 8 楼 jiang_jiajia10 的回复:]


C# codesqlstr = "select A from table where years=2000 and months=2" ;
BaseService bc = new BaseService();
DataTable dt = bc.ExecuteDataTable(sqlstr );
foreach (DataRow dr in dt.Rows)
{
int n = dr["A"].ToString();

}



BaseService bc = new BaseService();
写一些数据库读取的代码，因为这是我自己定义的方法。
[/Quote]

[kerry030401]

现在问题我需要2个sql语句都赋值给变量，再进行相减～请问这2个sql语句分别怎么放入sqldatareader？

[超人Q]

[Quote=引用 2 楼 yangpeiyu 的回复:]
declear @变量 int
select @变量=A from table where years=2000 and months=2
[/Quote]

[超人Q]

可以写成存储过程,在读取

[brooklyng60]

用个存储过程带两个参数啊,然后执行2次,如果有写死,可以带4个参数,直接返回相减的值也行
create proc minus
@year1 int,
@month1 int
@year2 int,
@month2 int
as
declare @num1 int
declare @sql1 nvarchar(2000)
set @sql1 ='select @num1=A from table where years=' + cast(@year1 as nvarchar(20))+ 'and month=' + cast(@month1 as nvarchar(20))
exec(@sql1)

declare @num2 int
declare @sql2 nvarchar(2000)
set @sql2 ='select @num2=A from table where years=' + cast(@year2 as nvarchar(20))+ 'and month=' + cast(@month2 as nvarchar(20))
exec(@sql2)

select (@num1-@num2) as number

[zhangxiaopin]

declare @aaa int

select @aaa=a from tablename where 1=1

[kerry030401]

[Quote=引用 16 楼 brooklyng60 的回复:]
用个存储过程带两个参数啊,然后执行2次,如果有写死,可以带4个参数,直接返回相减的值也行
create proc minus
@year1 int,
@month1 int
@year2 int,
@month2 int
as
declare @num1 int
declare @sql1 nvarchar(2000)
set @sql1 ='select @num1=A from table where years=' + cast(@year1 as nvarchar(20))+ 'and month=' + cast(@month1 as nvarchar(20))
exec(@sql1)

declare @num2 int
declare @sql2 …
[/Quote]
这位兄弟 可以再详细点嘛？做完这个存储过程后再怎么操作？我对存储过程可以说是非常的不懂的，谢谢！

[brooklyng60]

然后执行存储过程就可以得到结果啊,因为我们用到了Sqlhepler,一些简单的语句都用这了
public static int getNum(int year1,int month1 int year2,int month2)
{
return Convert.ToInt32(SqlHelper.ExecuteScalar(ConfigurationSettings.AppSettings["ConnectionString"].ToString(),"minus ",year1,month1,year2,month2));
}

[财富实验室]

寻寻觅觅为的就是答案阿！

[suyiming]

[code=C#]declear @sum int
select @sum=cast((select A from table where years=2000 and months=2) as int)
print @sum[
/*
declare @sum int
select @sum=2
print @sum

====
输出

2
*/code]

[suyiming]

select @sum=cast((select A from table where years=2000 and months=2) as int) 
print @sum[ 
/* 
declare @sum int 
select @sum=2 
print @sum 

==== 
输出 

2 
*/

[suyiming]

declear @sum int 
select @sum=cast((select A from table where years=2000 and months=2) as int) 
print @sum
/* 
测试
declare @sum int 
select @sum=2 
print @sum 

==== 
输出 

2 
*/

[潜水VIP]

[Quote=引用 8 楼 的回复:]
C# code
sqlstr = "select A from table where years=2000 and months=2" ;
BaseService bc = new BaseService();
DataTable dt = bc.ExecuteDataTable(sqlstr );
foreach (DataRow dr in dt.Row……
[/Quote]

谢谢分享！