Server Error in '/' Application.

SELECT tbl_subject.fld_gradeID,fld_type,(select  fld_title from tbl_grade where fld_id=tbl_subject.fld_gradeID)as GradeName   FROM  tbl_subject where fld_type = and  fld_gradeID in (1,2) order by fld_gradeID asc  <br>Incorrect syntax near the keyword 'and'.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Exception: SELECT tbl_subject.fld_gradeID,fld_type,(select  fld_title from tbl_grade where fld_id=tbl_subject.fld_gradeID)as GradeName   FROM  tbl_subject where fld_type = and  fld_gradeID in (1,2) order by fld_gradeID asc  <br>Incorrect syntax near the keyword 'and'.

Source Error:


Line 64:             catch (Exception ex)
Line 65:             {
Line 66:                 throw new Exception(sqlStr + " <br>" + ex.Message);
Line 67:             }
Line 68:             finally

Source File: c:\WebServer\areeg\App_Code\Cdb.cs    Line: 66

Stack Trace:


[Exception: SELECT tbl_subject.fld_gradeID,fld_type,(select  fld_title from tbl_grade where fld_id=tbl_subject.fld_gradeID)as GradeName   FROM  tbl_subject where fld_type = and  fld_gradeID in (1,2) order by fld_gradeID asc  <br>Incorrect syntax near the keyword 'and'.]
   Cdb.OleExecDataSet(String sqlStr) in c:\WebServer\areeg\App_Code\Cdb.cs:66
   ebooks.selectebookBySType(String Type, String GradeId) in c:\WebServer\areeg\App_Code\ebooks.cs:103
   Seraj_searchResult.FilleGrades(String Fld_Type, String GradeId) in c:\WebServer\areeg\Te-book.aspx.cs:93
   Seraj_searchResult.Page_Load(Object sender, EventArgs e) in c:\WebServer\areeg\Te-book.aspx.cs:85
   System.Web.UI.Control.OnLoad(EventArgs e) +108
   System.Web.UI.Control.LoadRecursive() +90
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1533


Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.8.4110.0