在 vb 中使用 Adox 在 Access 数据库中创建表

Question

我在 Visual Basic 2012 中使用 Windows 窗体应用程序使用 .ADOX 创建新的 Microsoft Access 数据库。 我可以创建数据库，但不能在数据库中创建表。

我的代码是：

Imports ADOX
Imports System.Data.OleDb
Public Class Form1
Dim mycommand As OleDbCommand
Dim myconnection As OleDbConnection
Dim myReader As OleDbDataReader
Dim str As String
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim cat As New Catalog()
    Dim tablename As String = "Users"
    cat.Create("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=F:\important\DDL.mdb;Jet OLEDB:Engine Type=5")
    cat = Nothing
    myconnection = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=F:\important\DDL.mdb ")
    myconnection.Open()
    str = "CREATE TABLE [ " & tablename & "] ([Username] varchar(50)), ([Password] varchar(50)), ([E-mail] varchar(75))"
    mycommand = New OleDb.OleDbCommand(str, myconnection)
    mycommand.ExecuteNonQuery()
    MsgBox("Database created")
End Sub
End Class

错误是：

An unhandled exception of type 'System.Data.OleDb.OleDbException' occurred in System.Data.dll

Additional information: Syntax error in CREATE TABLE statement.

任何帮助表示赞赏。

编辑：以下代码克服了第一个错误，但我现在遇到了字段定义错误，我知道代码应该可以正常工作，因为它可以添加数字字段，这可能是因为访问中的字段类型是短文本和长文本，但我可以试过好像不行。

Imports ADOX
Imports System.Data.OleDb
Public Class Form1
Dim mycommand As OleDbCommand
Dim myconnection As OleDbConnection
Dim myReader As OleDbDataReader
Dim str As String
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim cat As New Catalog()
    cat.Create("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=F:\important\DDL.mdb;Jet OLEDB:Engine Type=5")
    cat = Nothing
    myconnection = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=F:\important\DDL.mdb ")
    myconnection.Open()
    str = "CREATE TABLE [Users] (Username Varchar(50), Password Varchar(50), E-mail Varchar(50))"

    mycommand = New OleDb.OleDbCommand(str, myconnection)
    mycommand.ExecuteNonQuery()
    MsgBox("Database created")
End Sub
End Class

Answer 1

看起来您有太多括号，但我认为实际错误来自您查询中的前导空格：

                     V
str = "CREATE TABLE [ " & tablename & "]

尝试将其更改为：

str = "CREATE TABLE [" & tablename & "] ([Username] varchar(50), [Password] varchar(50), [E-mail] varchar(75))"

确保你处理了你的对象，最好是在 using 块中：

例子：

Using cn As New OleDb.OleDbConnection(mdb)
  cn.Open()
  Using cmd As New OleDb.OleDbCommand(str, cn)
    cmd.ExecuteNonQuery()
  End Using
End Using

Answer 2

最后的代码是这样的：

Imports ADOX
Imports System.Data.OleDb
Public Class Form1
    Dim mycommand As OleDbCommand
    Dim myconnection As OleDbConnection
    Dim myReader As OleDbDataReader
    Dim str As String
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim cat As New Catalog()
        cat.Create("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Test\DDL.mdb;Jet OLEDB:Engine Type=5")
        cat = Nothing
        Using myconnection As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Test\DDL.mdb ")
            myconnection.Open()
            str = "CREATE TABLE [Users] ([Username] varchar(50), [Password] varchar(50), [E-mail] varchar(50))"

            Using mycommand As New OleDb.OleDbCommand(str, myconnection)
                mycommand.ExecuteNonQuery()
            End Using
        End Using
        MsgBox("Database created")
    End Sub
End Class