更正此SQL查询：错误“Microsoft Jet数据库引擎无法找到输入表或查询'IF'”

Question

我应该打电话给专家：D。帮我看看这个漂亮的代码:)

数据库：

“ID（主键）” | “标题”
0 | “title1”
1 | “title2”
2 | “title3”
3 | “TITLE4”

---

Sub AddRecord(ByVal Table As String, ByVal Columns As String, ByVal Record() As String) 
    Dim SubDir As String = "" 

    Dim Adapter As OleDbDataAdapter = New OleDbDataAdapter("SELECT * FROM " & Table, connectionString) 
    Dim command As OleDbCommand 
    Dim tbCorrectSyntax = "" 

    Using connection As New OleDbConnection(connectionString) 
     Try 
      connection.Open() 
      Dim Commandtxt As String = "" 
      For i = 0 To Record.GetUpperBound(0) 
       If Record(i).IndexOf(",") > 0 Then 
        Dim tmpRec() As String = Nothing 
        Dim cols() As String = Nothing 

        tmpRec = Record(i).Split(",") 
        cols = Columns.Split(",") 

        For j = 0 To tmpRec.GetUpperBound(0) 
         tbCorrectSyntax &= cols(j) & " = '" & tmpRec(j) & "' " & IIf(j = tmpRec.GetUpperBound(0), "", " , ") 
        Next 
       End If 


       Dim txtCorrect As String = IIf(tbCorrectSyntax = "", Columns & " = " & Record(i), tbCorrectSyntax) 

       Commandtxt = "IF OBJECT_ID ('InsertOrUpdateItem', 'P') IS NOT NULL " & _ 
           "DROP PROCEDURE InsertOrUpdateItem " & _ 
          "GO " & _ 
          "CREATE PROCEDURE InsertOrUpdateItem " & _ 
           "AS " & _ 
           "IF (EXISTS (SELECT * FROM " & Table & _ 
              " WHERE " & txtCorrect & "))" & _ 
              " begin " & _ 
               "UPDATE (" & Table & ") " & _ 
               txtCorrect & _ 
               " WHERE " & txtCorrect & " " & _ 
              " End " & _ 
              " else " & _ 
               " begin " & _ 
               " INSERT INTO " & Table & " (" & Columns & ") " & _ 
               " VALUES (" & Record(i) & ")" & _ 
              " End " & _ 
           "End " 

       'Commandtxt = "INSERT INTO " & Table & " (" & Columns & ") VALUES (" & Record(i) & ")" 
       command = New OleDbCommand(Commandtxt, connection) 
       command.CommandType = CommandType.StoredProcedure 
       command.ExecuteNonQuery() 

      Next 


     Catch ex As Exception 
      msgbox(ex.Message) 
     Finally 
      connection.Close() 
     End Try 
    End Using 
End Sub 

Function connectionString() As String 
    Return "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & DBdir & ";User Id=admin;Password=;" 
End Function 

---

第一个程序是一个包装，以将数据添加到数据库字段（如果数据doent存在） 但随着新的数据已经存在更新的行。

输入：
表=表名
列=将由逗号更新分离colomns的名称（练习1： “ID”，实例2： “ID，标题，...”）
记录（）=字符串数组，代表新的值（多值与逗号分隔）

OK，增加值数据库之前，我们应该检查是否有行存在这个值:)
要做到这一点，创建一个存储过程一种快速处理数据库的最佳方法。

所以......现在的问题是，在运行时，OLEDB小姐抛出这个错误：
Microsoft Jet数据库引擎无法找到输入表或查询“IF” ....

在此先感谢：D

Answer 1

我发现我的问题的解决方案（一点点网研究:)）哈哈哈哈我很高兴
无论如何，最初的问题是：“如果存在如何更新数据库中的记录” 所以我tryed创建并存储在数据库中的存储过程...但是... :)

后来我发现一个有趣的方法：OleDbCommand的的ExecuteScalar

类

它只需根据输入的SQL语句返回值：在以下我用过的例子，如果recod存在，它会返回索引（主键）。因此，让我们开始：

Function GetRecordIndex(ByVal Table As String, ByVal Columns As String, ByVal Record As String) As String 
    Dim Commandtxt As String = "" 
    Dim Command As OleDbCommand 
    Dim tbCorrectSyntax As String = "" 
    Dim tbCorrectSyntaxAND As String = "" 

    Using connection As New OleDbConnection(connectionString) 

     Try 
      connection.Open() 
      If Record.IndexOf(",") > 0 Then 
       Dim tmpRec() As String = Nothing 
       Dim cols() As String = Nothing 

       tmpRec = Record.Split(",") 
       cols = Columns.Split(",") 

       For j = 0 To tmpRec.GetUpperBound(0) 
        tbCorrectSyntax &= cols(j) & "='" & tmpRec(j) & "' " & IIf(j = tmpRec.GetUpperBound(0), "", " , ") 
        tbCorrectSyntaxAND &= cols(j) & "='" & tmpRec(j) & "' " & IIf(j = tmpRec.GetUpperBound(0), "", " AND ") 
       Next 
      End If 
      Dim txtCorrect As String = IIf(tbCorrectSyntax = "", Columns & "=" & Record, tbCorrectSyntax) 
      Dim txtCorrectAND As String = IIf(tbCorrectSyntaxAND = "", Columns & "=" & Record, tbCorrectSyntaxAND) 

      Commandtxt = "SELECT * FROM " & Table & " WHERE " & txtCorrectAND 
      Command = New OleDbCommand(Commandtxt, connection) 
      Dim RecordIndex As String = Command.ExecuteScalar 

      Return RecordIndex 

     Catch ex As Exception 
      Return Nothing 
     Finally 
      connection.Close() 
     End Try 
    End Using 
End Function 

与之前一样，列参数可以是单个数据库列，也可以是多个用逗号分隔的列。与记录同样的事情，代表每列

谢谢里面的数据对你有所帮助
Fadelovesky

Answer 2

command.CommandType = CommandType.StoredProcedure 

您声称您正在运行存储过程（CommandText将是现有SProc的名称）。你实际上给了它一个直接执行的SQL命令。 CommandType应该是Text;