Zeolibs: Unknown column in Where clause

Question

I am trying to execute a SQL query using Zeolibs but compiler keeps complaining with the following error - Unknown column in Where clause.

ZQuery1.SQL.Text := 'SELECT * FROM new_table WHERE TagName = '+theSig.f.TagName;
ZQuery1.ExecSQL;

But I checked all the columns in my database table and it is correct as I have it here TagName

What is wrong with my SQL statement?

Answer 1

You need to use the QuotedStr function. So your code will be

ZQuery1.SQL.Text := 'SELECT * FROM new_table WHERE TagName = '+QuotedStr(theSig.f.TagName);

A better alternative is to use parametrized queries (this will block attempts for SQL injection - take a quick look at this question).

ZQuery1.SQL.Text := 'SELECT * FROM new_table WHERE TagName = :myparam';
ZQuery1.ParamByName('myparam').AsString := theSig.f.TagName;