SQL多欄位模糊查詢

http://user.qzone.qq.com/382164370#!app=2&via=QZ.HashRefresh&pos=1346996967

代碼是在VC++裡面:

CString sql, str;sql.Format(_T("SELECT * FROM tbPatient WHERE admitDateBETWEEN CDate('%s %s') AND CDate('%s %s')"),dtStartDate.Format(_T("%x")), dtStartTime.Format(_T("%X")),dtEndDate.Format(_T("%x")), dtEndTime.Format(_T("%X")));//欄位合并的模糊查詢 MYSQL concat(email,address) like 'like%df%'if(!strKeyWord.IsEmpty()){//SQL Server中IsNull(expression, replace)有替換功能, //Access需要結合IsNull ( expression ), iif (condition, value_if_true, value_if_false )函數//str.Format(_T(" AND IsNull(name, ' ') & IsNull(Empid, ' ') LIKE '%%%s%%'"), //strKeyWord.GetBuffer(0));str.Format(_T(" AND iif(IsNull(name),' ',name) & iif(IsNull(Empid),' ',Empid) LIKE  '%%%s%%'"), strKeyWord.GetBuffer(0));sql += str;}TRACE1("%s\n", sql);

一種改寫的代碼

CString sql, str;sql.Format(_T("SELECT * FROM tbPatient"));if (!m_bDisplayAll)//非全部顯示則添加搜尋條件{str.Format(_T(" WHERE admitDateBETWEEN CDate('%s %s') AND CDate('%s %s')"),dtStartDate.Format(_T("%x")), dtStartTime.Format(_T("%X")),dtEndDate.Format(_T("%x")), dtEndTime.Format(_T("%X")));sql += str;//欄位合并的模糊查詢 MYSQL concat(email, address) like 'like%df%'if(!strKeyWord.IsEmpty()){//SQL Server中IsNull(expression, replace)有替換功能, //Access需要結合IsNull ( expression ), iif (condition, value_if_true, value_if_false )函數//str.Format(_T(" AND IsNull(name, ' ') + IsNull(Empid, ' ') LIKE '%%%s%%'"), //strKeyWord.GetBuffer(0));str.Format(_T(" AND iif(IsNull(name),' ',name) & iif(IsNull(Empid),' ',Empid) LIKE  '%%%s%%'"), strKeyWord.GetBuffer(0));sql += str;}}//sql += _T(" ORDER BY ASC");//DESC, 添加排序TRACE1("%s\n", sql);