passing C++ variables to SQL statement

Hello,

I have a recordset open function and would like to limit the returned recordset with a WHERE statement. It works without problems if the value after WHERE is just a literal string, however, that value must be a variable that will change. When I substitue with a variable, the program crashes.

How can I insert a variable there instead of using a predefined value??

Doesnt work:

CString MyVariable = "helpme";

recordset.Open(AFX_DAO_USE_DEFAULT_TYPE, "SELECT * FROM MyTable WHERE NameField = MyVariable",NULL);


Does work:

recordset.Open(AFX_DAO_USE_DEFAULT_TYPE, "SELECT * FROM MyTable WHERE NameField = 'helpme'",NULL);


I am using visual C++ and trying to connect to a Microsoft Access database if that makes a difference,

Thank you!!!

We were just talking about this:


Now, that is assuming that recordset.Open() accepts a CString as its second parameter. If it does not, then you should create a CString (eg, MySQLstring) for the entire SQL statement, concatenate your variable value in as shown, and do whatever you need to to get Open to read it, like maybe MySQLstring.GetBuffer().

Thank you for your reply -

I also happened upon a way to do it as follows:

CString MyVariable = "Mr. Bigglesworth";

CString sSql;
sSql.Format("SELECT * FROM NamesTable WHERE NameField = '%s' ", (LPCSTR)MyVariable);

recordset.Open(AFX_DAO_USE_DEFAULT_TYPE, sSql, NULL);

Diabolical!

Hope that helps someone down the road.

Yep, does the same thing. Perl isn't the only language with more than one way.

Basically, CString's Format() method implements the functionality of the sprintf function. I haven't played with MFC for a while, so it slipped my mind.

Nice to see that Open takes a CString argument.