Sending parameters to stored procedures vb.net
Solution 1
If you're just reading data then checkout the SqlDataReader:
Dim reader As SqlDataReader
reader = cmd.ExecuteReader()
While reader.Read
//Do stuff with reader
End While
If you are doing an update or an insert then you can use the ExecuteNonQuery() method of the SqlCommand class.
SqlCommand has a shorthand for adding parameters:
cmd.Parameters.AddWithValue("@MyParamName", myParamValue)
Which you may find useful.
And yes you should open and close a database connection every time you need to interact with the database. Read up on the Using statement, which will help you to do this nice and neatly.
Solution 2
You don't need a separate database connection for each call, you can open it once and send it into each method that uses it, then close it.
It's important however that you close or dispose connections and commands that you use. If you don't, the connection will remain open for some time until the database itself kills it. If you leave enough connections hanging, you will run out of resources.
A SqlDataAdapter
and a DataSet
is only needed if the stored procedure returns a result, and only if you want that result in a DataSet
object. You can use the SqlCommand.ExecuteNoQuery
method to run a stored procedure that doesn't return any result. You can also get a result in a SqlDataReader
and read the data from that if you don't want to use a DataSet
.
Note: You have to create one SqlParameter
for each parameter. Now you create one parameter and change that over and over, so the parameter collection will end up having ten references to the same parameter.
Diego
Updated on October 23, 2020Comments
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Diego over 3 years
Hello this my first project in vb.net working with ms visual studio 2010, i want to create a class that can send parameters to stored procedures in an transact-sql database, i know how to do it in vb 6 but i'm not sure if this the right way to do it in here.
Imports System.Data.SqlClient Public Class ClsLineas Public Sub Inserta(ByVal GridLineas As DataGrid, _ ByVal numero As String, _ ByVal tipo As String, _ ByVal estado As String, _ ByVal anexo As Integer, _ ByVal fechaInicio As String, _ ByVal fechaFin As String, _ ByVal pcReg As String, _ ByVal observaciones As String, _ ByVal usuReg As String) Dim cnx As SqlConnection = New SqlConnection(ClsCon.connectionString) 'ClsCon.connectionString is a class that contains the connection string Dim cmd As SqlCommand = New SqlCommand() If cnx.State = ConnectionState.Closed Then cnx.Open() cmd.Connection = cnx cmd.CommandText = "SP_INSERTA_LINEA" cmd.CommandType = CommandType.StoredProcedure Dim prm As New SqlParameter prm.ParameterName = "@TIPO" prm.SqlDbType = SqlDbType.NVarChar prm.Size = 30 prm.Direction = ParameterDirection.Input prm.Value = tipo cmd.Parameters.Add(prm) prm.ParameterName = "@FECHA_INICIO" prm.SqlDbType = SqlDbType.NVarChar prm.Size = 30 prm.Direction = ParameterDirection.Input prm.Value = fechaInicio cmd.Parameters.Add(prm) prm.ParameterName = "@FECHA_FIN" prm.SqlDbType = SqlDbType.NVarChar prm.Size = 30 prm.Direction = ParameterDirection.Input prm.Value = fechaFin cmd.Parameters.Add(prm) prm.ParameterName = "@ESTADO" prm.SqlDbType = SqlDbType.NVarChar prm.Size = 30 prm.Direction = ParameterDirection.Input prm.Value = estado cmd.Parameters.Add(prm) prm.ParameterName = "@NUMERO" prm.SqlDbType = SqlDbType.NVarChar prm.Size = 15 prm.Direction = ParameterDirection.Input prm.Value = numero cmd.Parameters.Add(prm) prm.ParameterName = "@ANEXO" prm.SqlDbType = SqlDbType.Int prm.Direction = ParameterDirection.Input prm.Value = anexo cmd.Parameters.Add(prm) prm.ParameterName = "@PC_REG" prm.SqlDbType = SqlDbType.NVarChar prm.Size = 50 prm.Direction = ParameterDirection.Input prm.Value = pcReg cmd.Parameters.Add(prm) prm.ParameterName = "@USU_REG" prm.SqlDbType = SqlDbType.NVarChar prm.Size = 50 prm.Direction = ParameterDirection.Input prm.Value = usuReg cmd.Parameters.Add(prm) prm.ParameterName = "@OBSERVACIONES" prm.SqlDbType = SqlDbType.NVarChar prm.Size = 1000 prm.Direction = ParameterDirection.Input prm.Value = observaciones cmd.Parameters.Add(prm) prm.ParameterName = "@ID" prm.SqlDbType = SqlDbType.Int prm.Direction = ParameterDirection.Output cmd.Parameters.Add(prm) Dim adp As SqlDataAdapter = New SqlDataAdapter(cmd) Dim DataSet As DataSet = New DataSet("Lineas") adp.Fill(DataSet) GridLineas.DataSource = DataSet.Tables(0) End Sub End class
Some of my doubts are:
Do i really need to open the database every time i call the methods of my class?
Are the sqlAdapter and Dataset really needed? In vb 6 you could do something like "command execute inserta" after appending the parameters and you where done.