Using SqlCommand , how to add multiple parameters

Question

I have ten textboxes in my winform, and i need to save the text typed in these textboxes into 10 columns of a sql database table. so, for this shall i write :

INSERT INTO item (c1,c2,c3...,c10) values (@a,@b....@j) 

cmd.Parameters.Add("@a",SqlDbType.Varchar)
cmd.Parameteres["@a"].Value=textbox1.Text;

cmd.Parameters.Add("@b",SqlDbType.Varchar)
cmd.Parameteres["@b"].Value=textbox2.Text;.
.
.
.
.
cmd.Parameters.Add("@j",SqlDbType.Varchar)
cmd.Parameteres["@j"].Value=textbox10.Text;

OR ten separate queries for each textbox:

INSERT INTO item (c1) values (@a)
cmd.Parameters.Add("@a",SqlDbType.Varchar)
cmd.Parameteres["@a"].Value=textbox1.Text;

INSERT INTO item (c2) values (@b) 
cmd.Parameters.Add("@b",SqlDbType.Varchar)
cmd.Parameteres["@b"].Value=textbox2.Text;.
.
.
INSERT INTO item (c10) values (@j)
cmd.Parameters.Add("@j",SqlDbType.Varchar)
cmd.Parameteres["@j"].Value=textbox10.Text;

or, please suggest an efficient code.

How to add multiple parameters to cmd in a single statement? is it possible?

Answer 1

You can use an extension method, like this:

public static class DbCommandExtensions
{
    public static void AddInputParameters<T>(this IDbCommand cmd,
        T parameters) where T : class
    {
        foreach (var prop in parameters.GetType().GetProperties())
        {
            object val = prop.GetValue(parameters, null);
            var p = cmd.CreateParameter();
            p.ParameterName = prop.Name;
            p.Value = val ?? DBNull.Value;
            cmd.Parameters.Add(p);
        }
    }
}

Then call it like this:

cmd.AddInputParameters(new { a = textBox1.Text, b = TextBox2.Text, /* etc */ });

I've used that in a few projects with no problems.

Answer 2

The 2 'solutions' that you suggest in your question, are semantically different. Which one you should use, depends on your table-layout.

The first solution inserts one record in the table, the second insert statement inserts one record (row) for every value (textbox).

Difficult to give a good answer here, since we do not know what you're going to save in that table, and thus , we cannot say how you should save it (how you save it, is inherintly dependent on the way you should call the SQL insert statement).

Answer 3

I think you can use Parameters.AddWithValue() method.

cmd.Parameters.AddWithValue("@j",textbox10.Text);
cmd.Parameters.AddWithValue("@k",textbox11.Text);
cmd.Parameters.AddWithValue("@l",textbox12.Text);

Answer 4

You could use a function like this:

void AddParams(DBCommand cmd,params object[] parameters)
{
    if (parameters != null)
    {
        int index = 0;
        while (index < parameters.Length)
        {
            cmd.Parameters.AddWithValue("@"+(string)parameters[index], parameters[index + 1]);
            index += 2;
        }
    }
}

Not the best one probably, but functional. Call link this:

AddParams(a,"test1",b,3,c,DateTime.Now);

Or you can use an extension like suggested from @Matt Hamilton to add this function in DBCommand class.