Allow Null values to be saved in database - sql

Question

Im using Visual Studio .NET 2003 the add button works fine when all textbox, combobox fields are filled with data, but upon testing not filling the fields with data leaving it NULL it returns error saying "String was not recognized as a valid DateTime"
I have a textbox named txtPurchasedDate
My Stored procedure
CREATE PROCEDURE AddOfficeEquipmentProfile
(
#OE_ID varchar(11) = NULL,
#OE_Category char(3) = NULL,
#OE_SubCategory char(3) = NULL,
#OE_Name varchar(35) = NULL,
#OE_User varchar(35) = NULL,
#OE_Brand varchar(15) = NULL,
#OE_Model varchar(35) = NULL,
#OE_Specs varchar(1000) = NULL,
#OE_SerialNo varchar(35) = NULL,
#OE_PropertyNo varchar(35) = NULL,
#OE_MacAddress varchar(100) = NULL,
#OE_Static_IP varchar(15) = NULL,
#OE_Vendor varchar(35) = NULL,
#OE_PurchaseDate smalldatetime = NULL,
#OE_WarrantyInclusiveYear int = NULL,
#OE_WarrantyStatus char(2) = NULL,
#OE_Status varchar(15) = NULL,
#OE_Dept_Code char(3) = NULL,
#OE_Location_Code char(8) = NULL,
#OE_Remarks varchar(1000) = NULL
)
AS
INSERT INTO tblOfficeEquipmentProfile (OE_ID, OE_Category, OE_SubCategory, OE_Name, OE_User, OE_Brand, OE_Model, OE_Specs, OE_SerialNo,
OE_PropertyNo, OE_MacAddress, OE_Static_IP, OE_Vendor, OE_PurchaseDate, OE_WarrantyInclusiveYear, OE_WarrantyStatus, OE_Status, OE_Dept_Code,
OE_Location_Code, OE_Remarks )
VALUES (#OE_ID, #OE_Category, #OE_SubCategory, #OE_Name, #OE_User, #OE_Brand, #OE_Model,
#OE_Specs, #OE_SerialNo, #OE_PropertyNo, #OE_MacAddress, #OE_Static_IP, #OE_Vendor, #OE_PurchaseDate, #OE_WarrantyInclusiveYear, #OE_WarrantyStatus,
#OE_Status, #OE_Dept_Code, #OE_Location_Code, #OE_Remarks)
IF ##ERROR<>0
BEGIN
ROLLBACK TRANSACTION
RETURN 0
END
ELSE
BEGIN
COMMIT TRANSACTION
RETURN 1
END
GO
My Vb.net Add Button Code
Dim cmd As SqlCommand = sqlconn.CreateCommand
sqlconn.Open()
cmd.CommandType = CommandType.StoredProcedure
cmd.CommandText = "AddOfficeEquipmentProfile"
cmd.Parameters.Add("#OE_ID", SqlDbType.VarChar, 11, "oeq-su-999")
cmd.Parameters.Add("#OE_Category", SqlDbType.Char, 3, "COM")
cmd.Parameters.Add("#OE_SubCategory", SqlDbType.Char, 3, "SU")
cmd.Parameters.Add("#OE_Name", SqlDbType.VarChar, 35, "adminpmis01")
cmd.Parameters.Add("#OE_User", SqlDbType.VarChar, 35, "Ivan")
cmd.Parameters.Add("#OE_Brand", SqlDbType.VarChar, 15, "DELL")
cmd.Parameters.Add("#OE_Model", SqlDbType.VarChar, 35, "optiplex")
cmd.Parameters.Add("#OE_Specs", SqlDbType.VarChar, 1000, "dualcore")
cmd.Parameters.Add("#OE_SerialNo", SqlDbType.VarChar, 35, "sgh5960")
cmd.Parameters.Add("#OE_PropertyNo", SqlDbType.VarChar, 35, "j7h7h6g6f2")
cmd.Parameters.Add("#OE_MacAddress", SqlDbType.VarChar, 100, "j7h7:h6g6f2")
cmd.Parameters.Add("#OE_Static_IP", SqlDbType.VarChar, 15, "192.168.1.5")
cmd.Parameters.Add("#OE_Vendor", SqlDbType.VarChar, 35, "ADWAYS")
cmd.Parameters.Add("#OE_PurchaseDate", SqlDbType.SmallDateTime)
cmd.Parameters.Add("#OE_WarrantyInclusiveYear", SqlDbType.Int)
cmd.Parameters.Add("#OE_WarrantyStatus", SqlDbType.Char, 2, "IN")
cmd.Parameters.Add("#OE_Status", SqlDbType.VarChar, 15, "Good")
cmd.Parameters.Add("#OE_Dept_Code", SqlDbType.Char, 3, "ADM")
cmd.Parameters.Add("#OE_Location_Code", SqlDbType.Char, 8, "ADM_OFC")
cmd.Parameters.Add("#OE_Remarks", SqlDbType.VarChar, 1000, "ACTIVE")
cmd.Parameters("#OE_ID").Value = txtOEID.Text
cmd.Parameters("#OE_Category").Value = cmbCategory.Text
cmd.Parameters("#OE_SubCategory").Value = cmbSubCategory.Text
cmd.Parameters("#OE_Name").Value = txtName.Text
cmd.Parameters("#OE_User").Value = txtUser.Text
cmd.Parameters("#OE_Brand").Value = cmbBrand.Text
cmd.Parameters("#OE_Model").Value = cmbModel.Text
cmd.Parameters("#OE_Specs").Value = txtSpecs.Text
cmd.Parameters("#OE_SerialNo").Value = txtSerialNo.Text
cmd.Parameters("#OE_PropertyNo").Value = txtPropertyNo.Text
cmd.Parameters("#OE_MacAddress").Value = txtMacAddress.Text
cmd.Parameters("#OE_Static_IP").Value = txtStaticIp.Text
cmd.Parameters("#OE_Vendor").Value = txtVendor.Text
cmd.Parameters("#OE_PurchaseDate").Value = txtPurchaseDate.Text
cmd.Parameters("#OE_WarrantyInclusiveYear").Value = txtWarrantyInclusiveYear.Text
cmd.Parameters("#OE_WarrantyStatus").Value = txtWarrantyStatus.Text
cmd.Parameters("#OE_Status").Value = txtStatus.Text
cmd.Parameters("#OE_Dept_Code").Value = cmbDeptCode.Text
cmd.Parameters("#OE_Location_Code").Value = cmbLocationCode.Text
cmd.Parameters("#OE_Remarks").Value = txtRemarks.Text
cmd.ExecuteNonQuery()
MsgBox("Successfully Added Equipment Profile")
sqlconn.Close()

Answer 1

If you want to store null values, you have to use conditional logic in your vb code to either not send those parameters to your stored procedure, or send a value of dbnull. Even your char fields are storing empty strings, which might not be your intent.

Answer 2

Use
If (Not String.IsNullOrEmpty(txtPurchaseDate.Text)) Then
cmd.Parameters("#OE_PurchaseDate").Value = txtPurchaseDate.Text
End If

Answer 3

Why not use DateTimePicker for your PurchaseDate instead of a textbox in txtPurchaseDate.Text you could name your control dtpPurchaseDate then you have:
cmd.Parameters("#OE_PurchaseDate").Value = dtpPurchaseDate.Value
The Default Value (or the Minimum Value) for DateTime Picker is 1/1/1980 so you could initialize the value of dtpPurchaseDate to 1/1/1980 like:
dtpPurchaseDate = System.DateTime.Parse("1/1/1980")
So, which means by the way when stored in your database it has the value of 1/1/1980 and not NULL.
If you want to purse with the Textbox then you could check if empty then assign a minimum date value which is actually 1/1/0001 like this:
If (If (String.IsNullOrEmpty(txtPurchaseDate.Text)) Then
cmd.Parameters("#OE_PurchaseDate").Value = DBNull.Value
Else
Dim tempPurchaseDate as DateTime
System.DateTime.TryParse(txtPurchaseDate.Text, tempPurchaseDate)
cmd.Parameters("#OE_PurchaseDate").Value = tempPurchaseDate
End If
But again it has a stored value in your database as 1/1/0001
You could display it empty in your TextBox like:
Given you have a DataRow named dr
If (dr["OE_PurchaseDate"] = System.DateTime.Parse("1/1/0001")) Then
txtPurchaseDate.Text = ""
Else
txtPurchaseDate.Text = dr["OE_PurchaseDate"]
End If