Conditional statements with sql query - sql-server

Question

I posted a question earlier but it is so complicated that I think that's the reason why nobody tries to answer it. So I decided to put this in the simplest way I can. So here is my code:
Private Sub frmcrc_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
conn = GetConnect()
Dim com As New SqlClient.SqlCommand
Dim dr As SqlClient.SqlDataReader
conn.Open()
com.CommandText = "Select * from tblCRClearance where crc_no = '" & frmComm.txtCRCNum1.Text & "'"
com.Connection = conn
dr = com.ExecuteReader
dr.Read()
txtCRCNo.Text = dr!crc_no
txtCLTAcctNo.Text = dr!crc_clientno
lblrootpayee.Text = dr!crc_rootpayee
txtPayeeName.Text = dr!crc_payeename
txtClientName.Text = dr!crc_clientname
txtProjName.Text = dr!crc_projectname
txtCommType.Text = dr!crc_commtype
txtGrossAmt.Text = dr!crc_grossamount
txtWTax.Text = dr!crc_withheld
txtCALType1.Text = dr!crc_caliqtype1
txtCALDate1.Text = dr!crc_caliqdate1
txtCALNo1.Text = dr!crc_caliqnum1
txtCALAmt1.Text = dr!crc_caliqamt1
txtCALDesc1.Text = dr!crc_caliqdesc1
txtCALType2.Text = dr!crc_caliqtype2
txtCALNo2.Text = dr!crc_caliqnum2
txtCALAmt2.Text = dr!crc_caliqnum2
txtCALDate2.Text = dr!crc_caliqdate2
txtCALDesc2.Text = dr!crc_caliqdesc2
txtCALType3.Text = dr!crc_caliqtype3
txtCALDate3.Text = dr!crc_caliqdate3
txtCALNo3.Text = dr!crc_caliqnum3
txtCALAmt3.Text = dr!crc_caliqamt3
txtCALDesc3.Text = dr!crc_caliqdesc3
txtCALIQ.Text = dr!crc_caliqtotal
txtNetAmt.Text = dr!crc_netamount
txtVoucherNum.Text = dr!crc_voucherno
txtCRLNum.Text = dr!crc_crlno
txtDate.Text = dr!crc_date
txtCPFNo.Text = dr!crc_cpfno
txtPreparedBy.Text = dr!crc_preparedby
txtCheckedBy.Text = dr!crc_checkedby
txtApprovedBy.Text = dr!crc_approvedby
txtGrossPrice.Text = dr!crc_grossprice
txtLess1.Text = dr!crc_lessprice1
txtDesc1.Text = dr!crc_lessdesc1
txtLess2.Text = dr!crc_lessprice2
txtDesc2.Text = dr!crc_lessdesc2
txtLess3.Text = dr!crc_lessprice3
txtDesc3.Text = dr!crc_lessdesc3
txtNetSellingP.Text = dr!crc_netsellingprice
txtRate.Text = dr!crc_rate
txtGrossRel.Text = dr!crc_grossrelease
txtDed1.Text = dr!crc_ded1
txtDDesc1.Text = dr!crc_deddesc1
txtDed2.Text = dr!crc_ded2
txtDDesc2.Text = dr!crc_deddesc2
txtDed3.Text = dr!crc_ded3
txtDDesc3.Text = dr!crc_deddesc3
txtDed4.Text = dr!crc_ded4
txtDDesc4.Text = dr!crc_deddesc4
txtDed5.Text = dr!crc_ded5
txtNetRel.Text = dr!crc_netrelease
txtCollectibles.Text = dr!crc_collectibles
conn.Close()
txtCLTAcctNo.Text = frmComm.cmbAcctNo1.Text
txtCRLNum.Text = frmComm.txtCRLNo.Text
txtProjName.Text = frmComm.txtUnitCode1.Text
txtClientName.Text = frmComm.cmbClientName1.Text + " " + frmComm.Label13.Text
txtCommType.Text = frmComm.cmbParticulars1.Text
txtPayeeName.Text = frmComm.cmbPayee01.Text
Me.lblrootpayee.Text = frmComm.lblrootpayee.Text
End Sub
It works like this: the sql query gets the data with the crc number the same as in txtCRCNum1. It works just as how I want it to, but I have some issues about this. I have 30 textboxes just like txtCRCNum1, so there are going to be 30 different values of crc number, depending on which textbox will I get its value. I want to have a conditional statement wherein it checks if the textbox that should contain the crc number is empty. If it is empty, then the fields will display just do this:
txtCLTAcctNo.Text = frmComm.cmbAcctNo1.Text
txtCRLNum.Text = frmComm.txtCRLNo.Text
txtProjName.Text = frmComm.txtUnitCode1.Text
txtClientName.Text = frmComm.cmbClientName1.Text + " " + frmComm.Label13.Text
txtCommType.Text = frmComm.cmbParticulars1.Text
txtPayeeName.Text = frmComm.cmbPayee01.Text
Me.lblrootpayee.Text = frmComm.lblrootpayee.Text
If not empty, then it will execute the sql query part.
How should I put up the conditional statement so that it will work as I have described?

Answer 1

You can add procedures and methods to forms just like any other class. In this case, since the CRCForm in all cases depends on a crc value, we will pass it in the constructor.
Public Class frmcrc
' a crc value property
Private _crcVal As String = "" ' I am guessing it is string
' the constructor
public Sub New(crcval As String)
' This call is required by the designer.
InitializeComponent()
_crcVal = crcval
End Sub
' etc
End Class
When the user clicks one of the 30 (?!) textbox/button pairs. This requires a form instance rather than the VB default instance (ie frmcrc.Show) which is bad anyway.
Dim f As New frmCrc(txtCRCNum1.Text)
f.Show
The form now has the value it needs to work with whether it is from TB1, Tb2 or TB22. The form need not know or care where it came from. The query would use _crcVal in the SQL.
The existing form load code then just needs to deal with cases where _crcVal is String.Empty. If it is not String.Empty then just post the frmComm parts (which probably ought to be a class) Else perform the query and display results.
You could also add a CrcValue property to the form to execute the query and display the results without creating a new form instance, just use the new crcvalue.
EDIT
A class for the "other" stuff - I cant tell what the data represents, I'll call it BaseAcct:
Public|Friend Class BaseAcct
Public Property AccountNumber As String
Public Property UnitCode As String
' etc
End Class
Newer versions support auto implemented properties where that is all you need to define a property. Older versions, you will need to code a Get and Set. You could also add procedures like FetchData and DisplayData to have the class get the data from one form and post it to another, specifying which form as an parameter. The ELSE you have to copy data from one Form to the other could then be:
Dim BAcct As New BaseAcct
' ... etc
If _crcVal <> String.Empty Then
' ...
Else
BAcct.Display(Me) ' let the class post the data to this form
End If
The crcVal can be one of the Properties in the class, but even if it is, I would require that it be passed to frmcrc in the constructor since that form seems to be meaningless without it. That is, your code should not be able to create a form instance without that value.

Answer 2

First thing, you should be aware of all the 30 textboxes ids'. I dont know where would you place the if statement. but i would suggest you to have a button_click event where you will check all the textboxes.
Another thing for all the different 30 textboxes, Do you have the same textboxes like txtCRCNo,txtCLTAcctNo,lblrootpayee,etc.,
If it so , then you can allow only one textbox at a time.
So make textbox_TextChanged event for all the textboxes,while typing into a textbox all other textboxes should be empty.
Note: put all the textboxes in a panel.
like,
Sub txtCRCNum1_TextChanged()
txtCRCNum2.Text=""
txtCRCNum2.Enabled=False
' and so on
End Sub
Now it is easy to make your solution on button_click
Sub button_click()
Dim ctrl As New Control
For Each ctrl In Panel1.Controls
If TypeOf ctrl Is TextBox Then
If ctrl.Text <> "" Then
'sql query with that textbox
End If
End If
Next