更新sql语句

我的语句为str1.Format("UPDATE wz set title='%s',class='%s',nr='%s' WHERE title=m_xb1",
m_bt, strTemp, fromClipboard);
其中CString m_xb1;保存的值，但是这个语句里title就直接等于m_xb1。这该怎么办？

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str1.Format("UPDATE wz set title='%s',class='%s',nr='%s' WHERE title=%s",
m_bt, strTemp, fromClipboard,(LPCTSTR)m_xb1);

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C/C++ code:
str1.Format("UPDATE wz set title='%s',class='%s',nr='%s' WHERE title='%s'",
m_bt, strTemp, fromClipboard, m_title);

//都用了CString::Format了，还..

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str1.Format("UPDATE wz set title='%s',class='%s',nr='%s' WHERE title=%s",
m_bt, strTemp, fromClipboard,m_xb1);