database - 无法创建表并在数据库中插入值

Question

下面的代码假设创建一个数据库和一个表，其中列“FirstName”被分配了一个值“James”

Imports System.Data.SQLite
Public Class Form1
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        SQLiteConnection.CreateFile("c:\mydatabasefile.db3")
        Dim sqlConnection As New SQLite.SQLiteConnection()
        Dim sqlCommand As New SQLiteCommand

        sqlConnection.ConnectionString = "Data Source=c:\mydatabasefile.db3"
        sqlConnection.Open()
        sqlCommand.CommandText = "CREATE TABLE MyTable(EmpID INTEGER PRIMARY KEY ASC,  FirstName VARCHAR(25));"
        sqlCommand.CommandText = "INSERT INTO MyTable(FirstName) VALUES('James');"
        sqlConnection.Close()
    End Sub
End Class

但出于某种原因，该应用程序仅创建了一个大小为 0 字节的数据库。为什么它不起作用。我正在使用 我正在使用 SQLite ADO.NET Provider。 , VS 2010, 窗体

Answer 1

你永远不会执行sql命令

Public Class Form1
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        SQLiteConnection.CreateFile("c:\mydatabasefile.db3")
        Dim sqlConnection As New SQLite.SQLiteConnection()
        Dim sqlCommand As New SQLiteCommand("", sqlConnection)

        sqlConnection.ConnectionString = "Data Source=c:\mydatabasefile.db3"
        sqlConnection.Open()
        sqlCommand.CommandText = "CREATE TABLE MyTable(EmpID INTEGER PRIMARY KEY ASC,  FirstName VARCHAR(25));"
        sqlCommand.ExecuteNonQuery()
        sqlCommand.CommandText = "INSERT INTO MyTable(FirstName) VALUES('James');"
        sqlCommand.ExecuteNonQuery()
        sqlConnection.Close()
    End Sub


End Class

您还需要设置命令连接，您也可以通过说

sqlCommand.Connection = sqlConnection那应该可以解决你的问题