SQL查询（C＃）中的更新语句

Question

I am new to the C# programming. Facing the problem Incorrect syntax near 'First_Name'.! in the given below code:

private void button2_Click(object sender, EventArgs e)
    {
        SqlConnection con = new SqlConnection();
        con.ConnectionString = @"Data Source=HP\SQLEXPRESS100;Database=CD_Gallery;Integrated Security=true";
        con.Open();
        if (con.State == System.Data.ConnectionState.Open)
        {
            SqlCommand cmd = new SqlCommand("update Customer_Info First_Name ='" + fname.Text + "'");
            //'" + fname.Text.ToString() + "','" + lname.Text.ToString() + "','" + landmark.Text.ToString() + "','" + address.Text.ToString() + "','" + contact.Text.ToString() + "','" + email.Text.ToString() + "','" + dateTimePicker1.Text.ToString() + "','" + deposite.Text.ToString() + "')", con);
            cmd.Connection = con;
            cmd.CommandType = System.Data.CommandType.Text;
            int a = cmd.ExecuteNonQuery();
            if (a > 0)
            {
                MessageBox.Show("You Have Successfully Updated");
                Custid.Text = "";
                fname.Text = "";
                lname.Text = "";
                address.Text = "";
                contact.Text = "";
                email.Text = "";
                landmark.Text = "";
                deposite.Text = "";
            }
        }     
    }

Answer 1

Problem : You forgot to add word SET after your table name in update statement.

Solution1 : Add the word SET after table name in Update query (Don't Recommend this)

"update Customer_Info SET First_Name ='" + fname.Text + "'"

Warning : Your query is open to sql injection attacks .please use parameterised queries to avoid them

Solution 2: Using Parameterised Queries

Replace This:

SqlCommand cmd = new SqlCommand("update Customer_Info SET First_Name 
                                                             ='"+fname.Text+"'");

With This:

SqlCommand cmd = new SqlCommand("update Customer_Info First_Name = @fname");
cmd.Parameters.AddWithValue("@fname" , fname.Text);

Answer 2

您的问题不在C＃，SQL语法中（您错过了set关键字）

SqlCommand("update Customer_Info set First_Name ='" + fname.Text + "'");

Answer 3

you are missing SET keyword:

update Customer_Info SET First_Name ='" + fname.Text + "'"

and also provide where clause otherwise it will update all the records in your table.

Answer 4

您在查询中缺少set关键字，您必须像这样放置set

SqlCommand cmd = new SqlCommand("update Customer_Info set First_Name ='" + fname.Text + "'");