Question

在vb.net内部，下面的代码可以使用

cmd.CommandText = "CREATE TABLE Notes ( num INTEGER, name TEXT)"
Try
      cmd.ExecuteNonQuery()
Catch ex As Exception
      MsgBox("Error during save operation: " & ex.Message)
End Try

cmd.CommandText = "insert into Notes(num , name ) VALUES( 3, 'Bob') "
Try
    Console.WriteLine(cmd.ExecuteNonQuery())
Catch ex As Exception
    MsgBox("Error during save operation: " & ex.Message)
End Try

但是我想放一个Integer变量而不是插入数字3.我试过这个：

Dim count As Integer = 1
cmd.CommandText = "insert into Notes(num , name ) VALUES(" + count " + , 'Bob') "

Try
     Console.WriteLine(cmd.ExecuteNonQuery())
Catch ex As Exception
      MsgBox("Error during save operation: " & ex.Message)
End Try

但是我有例外：

Conversion from string "insert into Notes(isFirst" to type 'Double' is not valid.

我知道这一行：

"insert into Notes(num , name ) VALUES(" + count + ", 'Bob') "

似乎完全错了，但我找不到任何其他解决方案，因为我尝试了所有这些。

如何将count变量插入表中？

提前致谢。

Answer 1

您应该参数化查询。我不确定SQLite的确切语法，因为我使用的是Oracle，但这肯定会让你走上正轨。

Dim count As Integer
'Whatever code you need to get the count from the user.

cmd.CommandText = "insert into Notes(num , name ) VALUES( @count, 'Bob')"

Dim myParam As New SQLiteParameter("@count")
cmd.Parameters.Add(myParam)

'Continue with executing the query, storing the result, etc.

Answer 2

双引号的错误一侧有“+”符号：

cmd.CommandText = "insert into Notes(num , name ) VALUES(" + count " + , 'Bob') "

应该是

cmd.CommandText = "insert into Notes(num , name ) VALUES(" & count & ", 'Bob') "

正如ChrisStauffer所提到的，使用参数。总是

我无法使用vb.net将整数插入到sqlite表中

2 个答案: