我该如何解决这个问题 [英] How do I solve this prolem

问题描述

当我尝试执行以下代码时，我收到一条错误消息，指出条件表达式中的数据类型不匹配。我正在使用MS Access数据库



我尝试过：



这是代码

When i try to execute the following code, i get an error message saying data type mismatch in criteria expression. I am using MS Access database

What I have tried:

Here's the code

private void btnSave_Click(object sender, EventArgs e)

        {
            try
            {
                conn.Open();

                OleDbCommand cmd = new OleDbCommand();
                cmd.Connection = conn;
                cmd.CommandText = "insert into master (MOW,GK,CLASS,MAKE,MODEL,YOP,MNTH,PRICE,ENGINE_NUMBER,CHASSIS_NUMBER,CC,HP,LOCATION,LOGBOOK,MERCHANT,REPLACED_ENGINE_NUMBER,REMARKS,COUNTY) values('" + txtMOW.Text + "','" + txtGK.Text + "','" + txtCLASS.Text + "','" + txtMAKE.Text + "','" + txtMODEL.Text+ "','" + txtYOP.Text + "','" + txtMNTH.Text + "','" + txtPRICE.Text + "','" + txtENGINENUMBER.Text + "','" + txtCHASSISNUMBER.Text + "','" + txtCC.Text + "','" + txtHP.Text + "','" + txtLOCATION.Text + "','" + txtLOGBOOK.Text + "','" + txtMERCHANT.Text + "','" + txtRENGINENUMBER.Text + "','" + txtREMARKS.Text + "','" + txtCOUNTY.Text + "')";

                cmd.ExecuteNonQuery();
                MessageBox.Show("Data Saved !!!!");
                conn.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show("Error" + ex.Message);
            }

        }

推荐答案

不要这样做。

不要连接字符串来构建SQL命令。它让您对意外或故意的SQL注入攻击持开放态度，这可能会破坏您的整个数据库。请改用参数化查询。

您的问题可能会同时消失...

例如：

Don't do it like that.
Do not concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Use Parametrized queries instead.
The chances are that your problem will disappear at the same time...
For example:

using (OleDbCommand cmd = new OleDbCommand("INSERT INTO master (Col1, Col2) VALUES (?,?)", conn))
   {
   cmd.Parameters.AddWithValue("@COL1", valueForColumn1);
   cmd.Parameters.AddWithValue("@COL2", valueForColumm2);
   cmd.ExecuteNonQuery();
   }

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