这条SQL语句怎么写呀

[smallfeet1985]

p->strSql="SELECT * FROM 规则表 WHERE 阈值 <='"+m_dy+"'";这么写不对，说pointer addition requires integral operand
就是想查询出阈值小于等于m_dy的。不会了

[healer_kx]

CString a = "select * from tab where a <= {b}";
CString b = a.Replace("{b}", m_dy);
p->strSql = (const char*)b;

[zaodt]

数值型的，不要加单引号。

[thirddata]

CString strSql;
strSql.Format("SELECT * FROM 规则表 WHERE 阈值 <=%d",m_dy);

[菜牛]

CString::Format

[zaodt]

http://blog.csdn.net/zaodt/archive/2008/06/08/2525009.aspx

[HuiChen]

m_dy 是 double 类型的吧

CString str;
str.Format( _T("%f"), m_dy );
p->strSql="SELECT * FROM 规则表 WHERE 阈值 <="+str;

估计那对引号是不需要的。

[smallfeet1985]

m_dy是DOUBLE型的

[smallfeet1985]

现在想写这样的语句，查询出阈值小于等于m_dy并且单位为V，然后按规则号排列，大侠们怎么写呀，急

[HuiChen]

CString str;
str.Format( _T("%f"), m_dy );
p->strSql="SELECT * FROM 规则表 WHERE 阈值 <="+ str + " AND 单位 = 'V' ORDER BY 规则号";

[zhipingw2006]

CString str;
str.Format( _T("SELECT * FROM 规则表 WHERE 阈值 <=%f and 单位 = 'V' order by 规则号"), m_dy );