VB.NET數(shù)據(jù)庫實際范例解讀
作者:佚名
對于剛剛接觸VB.NET編程語言不久的朋友來說,可能對于如何操作數(shù)據(jù)庫產(chǎn)生一定的疑問。我們就一起通過這篇文章來一起看看VB.NET數(shù)據(jù)庫的基本代碼實現(xiàn)。
如今的一個程序開發(fā)中基本上都需要對數(shù)據(jù)庫進行一定的操作,才能完成整個程序的完善性。在這里我們會了解到有關(guān)VB.NET數(shù)據(jù)庫的一些操作方面的代碼實現(xiàn),方便大家對這一方面的解讀。#t#
VB.NET數(shù)據(jù)庫代碼示例:
- Imports System
- Imports System.Data
- Imports System.Data.SqlClient
- public Class MainClassclass MainClass
- Shared Sub Main()Sub Main()
- Dim thisConnection As New SqlConnection
("server=(local)\SQLEXPRESS;" & _ - "integrated security=sspi;database=
MyDatabase") - ' Sql Query
- Dim sql As String = "SELECT *
FROM Employee " - Dim insertSql As String = "INSERT
INTO Employee " & _ - "(ID, FirstName, LastName)VALUES" & _
- "(@ID, @FirstName, @LastName)"
- Try
- ' Create Data Adapter
- Dim da As New SqlDataAdapter
- da.SelectCommand = New SqlCommand
(sql, thisConnection) - ' Create and fill Dataset
- Dim ds As New DataSet
- da.Fill(ds, "Employee")
- ' Get the Data Table
- Dim dt As DataTable = ds.Tables
("Employee") - ' Display Rows Before Changed
- Console.WriteLine("Before altering
the dataset") - For Each row As DataRow In dt.Rows
- Console.WriteLine("{0} | {1} | {2}", _
- row("ID").ToString().PadRight(10), _
- row("FirstName").ToString().PadRight(10), _
- row("LastName"))
- Next
- ' Add A Row
- Dim newRow As DataRow = dt.NewRow()
- newRow("FirstName") = "Edna"
- newRow("LastName") = "Everage"
- newRow("ID") = "2"
- dt.Rows.Add(newRow)
- ' Display Rows After Alteration
- Console.WriteLine("=========")
- Console.WriteLine("After
altering the dataset") - For Each row As DataRow In dt.Rows
- Console.WriteLine("{0} | {1} | {2}", _
- row("ID").ToString().PadRight(10), _
- row("FirstName").ToString().PadRight(10), _
- row("LastName"))
- Next
- ' Insert employees
- ' 1. Create command
- Dim insertCmd As New SqlCommand
(insertSql, thisConnection) - ' 2. Map parameters
- insertCmd.Parameters.Add("@FirstName", _
- SqlDbType.NVarChar, 10, "FirstName")
- insertCmd.Parameters.Add("@LastName", _
- SqlDbType.NVarChar, 20, "LastName")
- insertCmd.Parameters.Add("@ID", _
- SqlDbType.Int, 15, "ID")
- ' 3. Insert employees
- da.InsertCommand = insertCmd
- da.Update(ds, "Employee")
- Catch ex As SqlException
- ' Display error
- Console.WriteLine("Error: "
& ex.ToString()) - Finally
- ' Close Connection
- thisConnection.Close()
- Console.WriteLine("Connection
Closed") - End Try
- End Sub
- End Class
以上就是對VB.NET數(shù)據(jù)庫的應(yīng)用代碼示例進行的詳細解讀,希望對大家有所幫助。
責任編輯:曹凱
來源:
博客園