Question

这是我的c＃代码中应该在特定按钮上执行的方法：

   private void button2_Click(object sender, EventArgs e)
    {
        try
        {

            string connectionString = "Data Source=LPMSW09000012JD\\SQLEXPRESS;Initial Catalog=Pharmacies;Integrated Security=True";
            SqlConnection con = new SqlConnection(connectionString);
            con.Open();
            string query = "SELECT Code, Description, Next_Code FROM Liguanea_Lane2 WHERE code LIKE '%" + search.Text + "%'; ";
            SqlCommand cmd = new SqlCommand(query, con);

            SqlDataReader dr = cmd.ExecuteReader();

            while (dr.Read())
            {
                string scode = dr.GetString(dr.GetOrdinal("next_code"));
                textBox2.Text = scode;

            }
        }
        catch (Exception ex)
        {

            MessageBox.Show(ex.ToString());
        }
        //next description
        try
        {

            string connectionString1 = "Data Source=LPMSW09000012JD\\SQLEXPRESS;Initial Catalog=Pharmacies;Integrated Security=True";
            SqlConnection con1 = new SqlConnection(connectionString1);
            con1.Open();
            string query1 = "SELECT Code, Description, Next_Description FROM Liguanea_Lane2 WHERE code LIKE '%" + search.Text + "%'; ";


            SqlCommand cmd1 = new SqlCommand(query1, con1);

            SqlDataReader dr1 = cmd1.ExecuteReader();

            while (dr1.Read())
            {
                string sdes = dr1.GetString(dr1.GetOrdinal("Next_Description"));
                textBox3.Text = sdes;

            }
        }
        catch (Exception ex)
        {

            MessageBox.Show(ex.ToString());
        }
        search.ResetText();
        textBox1.Clear();
        search.SelectedIndex = search.SelectedIndex + 1;
        textBox2.Clear();
        textBox3.Clear();

        string connectionString2 = "Data Source=LPMSW09000012JD\\SQLEXPRESS;Initial Catalog=Pharmacies;Integrated Security=True";
        SqlConnection con2 = new SqlConnection(connectionString2);
        con2.Open();
        string query2 = "UPDATE Liguanea_Lane2 SET Update_val= '0' where code = '" + search.Text + "'; ";


    }


}

其中的特定区块提出了问题：

   string connectionString2 = "Data Source=LPMSW09000012JD\\SQLEXPRESS;Initial Catalog=Pharmacies;Integrated Security=True";
        SqlConnection con2 = new SqlConnection(connectionString2);
        con2.Open();
        string query2 = "UPDATE Liguanea_Lane2 SET Update_val= '0' where code = '" + search.Text + "'; ";

要添加更多洞察力，它的功能是插入我的MSSQL数据库表中名为“update_val”的列。根据名为“search”的comboBox的输入插入此值。我在MSSQL中运行查询，它的工作原理。唯一的区别是，不是从comboBox接收，而是使用“WHERE”命令指定值。 c＃中的问题是它根本不更新MSSQL中的表。所以我在问我的语法是否错误。

PS。是的我知道应该实现参数化查询以避免SQL注入。这只是我自己的做法。因此，没有任何评论，因为它与此相关。

Answer 1

要执行更新命令，您需要执行更多类似的操作：

using (SqlConnection connection = new SqlConnection(
               connectionstring1)) // You won't need a second connection string if both are the same
    {
        SqlCommand command = new SqlCommand(query2, connection);
        command.Connection.Open();
        command.ExecuteNonQuery();
    }

我的查询没有正确执行

1 个答案: