Combining two Columns - sql

Question

I have an SQL table with 4 columns. The fourth column is FullName. I want this column to autofill itself from the results of 2nd and 3rd Column. ie.Firstname and Middlename.
I have tried this code
cn.Open()
Dim query As String
query = "Insert into Details(Adm,FirstName,MiddleName,FullName ) VALUES ('" & TextBox1.Text & "' , '" & TextBox2.Text & "', '" & TextBox3.Text & " ', CONCATE(Textbox2.text, ',', Textbox3.Text))"
cmd = New SqlCommand(query, cn)
reader = cmd.ExecuteReader
MessageBox.Show("Data Saved")

Answer 1

The section CONCATINATE will be like the following:
"CONCATE('" & Textbox2.text &"',',','" & Textbox3.Text & "'))"
But i wont tell you to use like this, since it may a worst suggestion. I prefer you to use parameters as well to avoid injection and specifying the types.
Example:
Dim query = "Insert into Details(Adm,FirstName,MiddleName,FullName ) VALUES (" & _
"#adm,#fName,#mName,CONCATE(#fNameC,',',#mNameC))"
Dim cmd As New SqlCommand(query, cn)
cmd.Parameters.Add("#adm", SqlDbType.VarChar).Value = TextBox1.Text
cmd.Parameters.Add("#fName", SqlDbType.VarChar).Value = TextBox2.Text
cmd.Parameters.Add("#mName", SqlDbType.VarChar).Value = TextBox3.Text
cmd.Parameters.Add("#fNameC", SqlDbType.VarChar).Value = TextBox2.Text
cmd.Parameters.Add("#mNameC", SqlDbType.VarChar).Value = TextBox3.Text
'Execute the query here

Answer 2

Before query first store two textbox value in one variable
cn.Open()
Dim query As String
Dim fullname As String
fullname = TextBox1.text + "" + TextBox2.text
query = "Insert into Details(Adm,FirstName,MiddleName,FullName ) VALUES ('" & TextBox1.Text & "' , '" & TextBox2.Text & "', '" & TextBox3.Text & " ', '" & fullname & '")"
cmd = New SqlCommand(query, cn)
reader = cmd.ExecuteReader
MessageBox.Show("Data Saved")

Answer 3

You can concatenate with String.Concat, and I advice you to use the Parameter to avoid sql injections, like this :
cn.Open()
Dim query As String
query = "Insert into Details(Adm,FirstName,MiddleName,FullName ) VALUES (#Adm,#FirstName,#MiddleName,#FullName)"
cmd = New SqlCommand(query, cn)
cmd.Parameters.Add(New SqlParameter("#Adm", TextBox1.Text))
cmd.Parameters.Add(New SqlParameter("#FirstName", TextBox2.Text))
cmd.Parameters.Add(New SqlParameter("#MiddleName", TextBox3.Text))
cmd.Parameters.Add(New SqlParameter("#FullName", String.Concat(TextBox2.Text, ",", TextBox3.Text)))
reader = cmd.ExecuteReader
MessageBox.Show("Data Saved")

Answer 4

Save the Firstname and Middlename values into variables and concat() them together before sending to the query.
cn.Open()
Dim query As String
Dim firstname As String
Dim middlename As String
Dim fullname As String
query = "Insert into Details(Adm,FirstName,MiddleName,FullName) VALUES (#Adm,#FirstName,#MiddleName,#FullName)"
firstname = TextBox2.Text
middlename = TextBox3.Text
fullname = String.Concat(firstname, ",", middlename)
cmd = New SqlCommand(query, cn)
cmd.Parameters.Add(New SqlParameter("#Adm", TextBox1.Text))
cmd.Parameters.Add(New SqlParameter("#FirstName", firstname))
cmd.Parameters.Add(New SqlParameter("#MiddleName",middlename))
cmd.Parameters.Add(New SqlParameter("#FullName", fullname))
reader = cmd.ExecuteReader
MessageBox.Show("Data Saved")
Note that the query builder has been reformatted to remove vulnerability to SQL injection.

Answer 5

Use following line instead of your.
query = "Insert into Details(Adm,FirstName,MiddleName,FullName ) VALUES ('" & TextBox1.Text & "' , '" & TextBox2.Text & "', '" & TextBox3.Text & " ', '" & Textbox2.Text & " " & Textbox3.Text & "')"