查询中的语法错误 [英] Syntax error in query

问题描述

所以，我想要做的是，如果我从前两个组合框中选择值并单击搜索，它应该在第三个文本框中显示结果。我正在使用Ms Access作为我的数据库。





在VB中编码以链接到数据库

So, what i am trying to do is, if i select values from the first two combo box and click search it should display the result in third text box. I am using Ms Access as my database.


coding in VB to link to DB

Imports System.Data.OleDb
Public Class Form1
    Dim v_HardnessDbconn As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;DataSource=C:\Users\Desktop\Hardness.accdb")
    Dim v_datareader As OleDbDataReader

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        v_HardnessDbconn.Open()
        v_HardnessDbconn.Close()
    End Sub

搜索框上的编码

coding on the search box

    Private Sub searchtext_Click(sender As Object, e As EventArgs) Handles searchtext.Click
        v_HardnessDbconn.Open()
        TextBox1.Clear()
        Dim Str As String

        Str = "SELECT * From Items Where (Material = '" & ComboBox1.Text & "', Hardness = '" & ComboBox2.Text & "')"
        Dim v_dbCommand As OleDbCommand

        v_dbCommand = New OleDbCommand(Str, v_HardnessDbconn)
        Dim v_dataReader As OleDbDataReader = v_dbCommand.ExecuteReader()
        If v_dataReader.HasRows Then
            While v_dataReader.Read
                TextBox1.Text = v_dataReader("Material Code").ToString

            End While
            v_HardnessDbconn.Close()
        End If


    End Sub
End Class

运行后出错

error getting after running it

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

Additional information: Syntax error (comma) in query expression '(Material = 'Plain Carbon Steel ( AISI 1010- AISI 1030)', Hardness = '150-180')'.

有人可以提供帮助。

我在这个表达式中是否有一些错误，我选择了两个值不同的组合框，然后在数据库中读取这些值以显示我的结果：

Can someone please help.
Is there some mistake i made in this expression, where i am choosing values from two different combo boxes and then reading those values in the database to display my result :

Str = "SELECT * From Items Where (Material = '" & ComboBox1.Text & "', Hardness = '" & ComboBox2.Text & "')"

或我的数据库出了什么问题？

or is something wrong with my database?

推荐答案

你好，



你需要条件之间的逻辑关系， OR / AND 等。

Hello,

You need a logical relationship between your condition, OR/AND etc.

Str = "SELECT * From Items Where Material='" & ComboBox1.Text & "' AND Hardness='" & ComboBox2.Text & "'"

会工作......

Will work...

除了解决方案1 ​​...



请不要使用命令像这样：

In addition to solution 1...

Please, do not use command like this:

Str = "SELECT * From Items Where Material='" & ComboBox1.Text & "' AND Hardness='" & ComboBox2.Text & "'"

而不是它，使用参数化查询：

Rather than it, use parameterized query:

Str = "SELECT * From Items Where Material=? AND Hardness=?"

如何使用它？

请参阅： OleDbParameterCollection.Add方法（OleDbParameter） [ ^ ]

这篇关于查询中的语法错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！