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Build SQL SELECT query on the fly from three tables ASP.NET - VB

Last Modified: 2012-05-06
I am building a job board for the community college I attend.

I need to search three tables simultaneously.

Table 1)  Employer Table - BusinessName, EmpID
Table 2)  Jobs Table - JobID, JobTitle, JobType, DateLastModified, Status
Table 3)  JobType Table - There are about 30 fields here, all with True or False values representing the different degree and certificate programs offered by the college.  I need to check for True values in any fields where the user checks a checkbox during their search.

I'm having trouble getting this third table into the query correctly.  

Here is a screenshot of the search page and the code that builds the SELECT statement, and a copy of the SELECT statement when the user checks "Full Time Permanent" and "Aerospace".

Partial Class StudentSearchJobs
    Inherits System.Web.UI.Page
    Protected Sub btn_Search_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btn_Search.Click
        Dim TypeCheck As Boolean = False
        Dim JobCommand As String = "SELECT DISTINCT JobID, " & _
                "JobTitle, " & _
                "DateLastModified, " & _
                "Employer.EmpID, " & _
                "Employer.Emp_BusinessName " & _
                "FROM [Jobs] INNER JOIN [Employer] " & _
                "ON Jobs.EmpID = Employer.EmpID " & _
                "WHERE Jobs.Status = 'Active' AND"
        '   Check every checkbox and build the query with all that are checked
        '   For the first four checkboxes set the TypeCheck flag to True the first time we hit one that is checked.
        '   For the last 22, set the FieldCheck flag to True
        '   Build the JobCommand
        '   Type of Work Checkboxes
        If CBT_FullTimePermanent.Checked = True Then
            JobCommand += " ([JobType] = 'Full Time Job')"
            TypeCheck = True
        End If
        If CBT_PartTimePermanent.Checked = True Then
            If TypeCheck = True Then
                JobCommand += " OR ([JobType] = 'Part Time Job')"
                JobCommand += " ([JobType] = 'Part Time Job')"
                TypeCheck = True
            End If
        End If
        If CBT_PaidInternships.Checked = True Then
            If TypeCheck = True Then
                JobCommand += " OR ([JobType] = 'Paid Internship')"
                JobCommand += " ([JobType] = 'Paid Internship')"
                TypeCheck = True
            End If
        End If
        If CBT_UnpaidInternships.Checked = True Then
            If TypeCheck = True Then
                JobCommand += " OR ([JobType] = 'Un-paid Internship')"
                JobCommand += " ([JobType] = 'Un-paid Internship')"
                TypeCheck = True
            End If
        End If
        '   Field of Study checkboxes
        If CBF_Aerospace.Checked = True Then
            JobCommand += " AND ([JobType.JobClassAerospace = True])"
        End If
        JobCommand += " ORDER BY [DateLastModified] DESC, [JobTitle];"
        Session("MyQuery") = JobCommand
        If TypeCheck = False Then
            lbl_error.Visible = True
            Exit Sub
        End If
    End Sub
End Class
"SELECT DISTINCT JobID, JobTitle, DateLastModified, Employer.EmpID, Employer.Emp_BusinessName FROM [Jobs] INNER JOIN [Employer] ON Jobs.EmpID = Employer.EmpID WHERE Jobs.Status = 'Active' AND ([JobType] = 'Full Time Job') AND ([JobType.JobClassAerospace = True]) ORDER BY [DateLastModified] DESC, [JobTitle];"

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