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sqldatabasedelphiwhere-clausezeos

Zeolibs: Unknown column in Where clause

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?

Solution

  • 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;