出现SQL Server错误：“已经有一个名为&#39; <my table> 在数据库中。 “表不在数据库中时”

Question

在Windows 7 Pro上运行的Visual Basic 2013 ASP.NET Web应用程序项目中，每次运行它都会收到此错误。

如果我在运行表之前将其删除，则我的应用会创建表，但会出现错误。

如果表在运行之前存在，则应用会尝试创建表，忽略错误并继续，但是出现错误。

Page_Load函数按预期Page_Load进行，没有错误，直到最后。

然后发生错误。

Imports System.Data.SqlClient

Public Class WebForm2

    Inherits System.Web.UI.Page


    Private ConnectionString As String = "Integrated Security=SSPI;" + "Initial Catalog=;" + "Data Source=localhost;"
    Private reader As SqlDataReader = Nothing
    Private conn As SqlConnection = Nothing
    Private cmd As SqlCommand = Nothing
    Private sql As String = Nothing

    Public Const DEBUG_DEFAULT_CLIENT_ID = "NATIONS_BURGERS"
    Public Const DEBUG_DEFAULT_JOB_ID = "FRY_COOK_2014_07_05"
    Public client_ID
    Public job_ID
    Public client_job_table

    ' InitializeS the job application page. 
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        ' Initialize data: 
        client_ID = DEBUG_DEFAULT_CLIENT_ID
        job_ID = DEBUG_DEFAULT_JOB_ID
        client_job_table = client_ID + "_" + job_ID

        ' App selects client job table : 
        Dim command_successful =
        ExecuteSQLStmt(" select * from " + client_job_table)
        ' Create table if it doesn't exist:
        If Not command_successful Then
            ExecuteSQLStmt("CREATE TABLE " + client_job_table + _
                        "(" + _
                        "FIRST_NAME varchar(255)," + _
                        "LAST_NAME varchar(255)," + _
                        "PHONE varchar(255)" + _
                        ");")

        End If

        set_22_button.Visible = GridView1.Visible
        set_333_button.Visible = GridView1.Visible
    End Sub


' Sends sql command to ehires database.
Private Function ExecuteSQLStmt(ByVal sql As String)
    ' Open the connection

    ConnectionString = "Data Source=<my IP>;Initial Catalog=<my database name>;Persist Security Info=True;User ID=Doug;Password=ThankYou!!"
    Dim connection As New SqlConnection(ConnectionString)

    connection.ConnectionString = ConnectionString
    connection.Open()
    cmd = New SqlCommand(sql, connection)
    Dim command_successful = True
    On Error Resume Next
    cmd.ExecuteNonQuery()
    If Err.Number Then
        command_successful = False
        Dim reason = Err.Description
    Else
        command_successful = True
    End If
    connection.Close()
    Return command_successful
End Function  'ExecuteSQLStmt 

Answer 1

您的连接字符串未指定目录名称（数据库名称），因此对“ MASTER”数据库执行查询。 如果您看那里，可能会发现您认为不存在的表

Private ConnectionString As String = @"Integrated Security=SSPI;" & _
                                      "Initial Catalog=.....database name here;" & _
                                      "Data Source=localhost;"

Answer 2

问题是我正在使用GridView UI控件查看表，但是GridView没有被更新，所以从不显示该表已经存在。

通过更新GridView解决了问题。