选择查询中出现错误：条件表达式中的数据类型不匹配

Question

I am using Access database ,and trying to fetch data of column of DataType Yes/No with value true , but its not working, and giving me following error

Data type mismatch in criteria expression.

below is query

cmd2 = new OleDbCommand("Select TOP " + PageSize + " DoctorID,FirstName&' '&LastName as [Doctor Name],ContactNo_1&' , '&ContactNo_2 as [Contact number],City,Email_ID from Doctor_Master WHERE Display='" + true.ToString() + "' ORDER BY DoctorID", con);

How do I check this Value WHERE Display='" + true.ToString() + "'

Answer 1

You are trying to compare string to a boolean thus the type mismatch. So, try removing the single quote from:

WHERE Display=" + true.ToString() + ""

You could also use Yes instead of True like:

WHERE Display= Yes"

or again use True

WHERE Display= True"

and hard coded by the way as Ahmed already suggested.