Passing array as parameter for sql query

Got it work with

private bool CheckValues(string checkString)
{
    string[] stringToCheck = checkString.Split(' ');
    foreach (string word in stringToCheck)
    {
        if (values.Contains(word.ToLower()))
        {
            return true;
        }
    }
    return false;
}
protected void btnAddClick(object sender, EventArgs e)
{
    if (!string.IsNullOrEmpty(txtActivitate.Text))
    {
        var text = txtActivitate.Text.ToString();
        values = Session["MyList"] as List; // Retrieve the list from the session
        if (CheckValues(text))
        {
            values = Session["MyList"] as List;
            foreach (string value in values)
            {
                Message.Text += value + "
";
            }

            txtActivitate.Text = string.Empty;
            txtActivitate.Focus();
        }
        else
        {
            values.Add(text);
            Session["MyList"] = values;

            foreach (string value in values)
            {
                Message.Text += value + "
";
            }

            txtActivitate.Text = string.Empty;
            txtActivitate.Focus();
        }
    }
}

Prasad, I tried your solution but it still double the data in List values and Session["MyList"]. I have to find a way to prevent adding doubled values, tried with

if (!string.IsNullOrEmpty(txtActivitate.Text))
{
    values = Session["MyList"] as List; // Retrieve the list from the session
    var text = txtActivitate.Text.ToString();
    for (int i = 0; i < values.Count; i++)
    {
        if (values[i].Contains(text)) // (you use the word "contains". either equals or indexof might be appropriate)
        {
            Session["MyList"] = values;
        }
        else
        {
            values.Add(text); // Add the new value to the list

            Session["MyList"] = values; // Update the list in the session
        }
    }
}

but is not working, no data is saved

Thank you Prasad, I was trying to declare a public array of strings, populated with first method and use valies in the second. With the Session I tried to preserve values in the list and use it in the second method. Most probably values were not preserved due to post back. I try later today your solution but most likely will work

It seems like you've declared two separate variables named values within the same scope, causing confusion between the class-level variable and the local variable declared inside the btnAddClick method. The issue arises because the local variable inside the method is hiding the class-level variable.

To resolve the "empty value" problem, you can differentiate between the local variable and the class-level variable by using different names. Here's the corrected code:

readonly string[] classLevelValues;

protected void btnAddClick(object sender, EventArgs e)
{
    List localValues = new List
    {
        txtActivitate.Text.ToString() + ","
    };

    // If you intended to use the class-level values, change the loop to iterate through classLevelValues
    for (int i = 0; i < localValues.Count; i++)
    {
        Message.Text += localValues[i] + "
";
    }
}

By differentiating the names between the class-level variable classLevelValues and the local variable localValues, you can avoid conflicts and ensure that the intended variable is used. Also, ensure that you're populating and iterating through the correct list based on your requirement (either the class-level variable or the local variable).

Well, I manage to have a work arround using a Session but now with every click of a button, the values added previously are doubled

public List values = new List();
protected void Page_Load(Object sender, EventArgs e)
{

    if (!IsPostBack)
    {
        Session["MyList"] = new List();
    }
}
protected void btnAddClick(object sender, EventArgs e)
{
    values = Session["MyList"] as List;

    if (!string.IsNullOrEmpty(txtActivitate.Text))
    {
        values.Add(txtActivitate.Text.ToString());
    }

    for (int i = 0; i < values.Count; i++)
    {
        Message.Text += values[i] + "
";
    }

    txtActivitate.Text = string.Empty; txtActivitate.Focus();

    Session["MyList"] = values;
}

What to do?

I did that already but no values are passed to second method. Full code below

public List values = new List();
protected void btnAddClick(object sender, EventArgs e)
{
    if (!string.IsNullOrEmpty(txtActivitate.Text))
    {
        values.Add(txtActivitate.Text.ToString());
    }

    for (int i = 0; i < values.Count; i++)
    {
        Message.Text += values[i] + "
";
    }
}

protected void btnSelectClick(object sender, EventArgs e)
{
    using (SqlConnection conn = new SqlConnection(connString))
    {
        string sqlQuery = "SELECT * FROM tblActivitate t1 JOIN tblEvaris t2 ON t1.AID = t2.AID JOIN tblMasura t3 on t2.EID = t3.EID WHERE t1.Activitate IN ({0}) ORDER BY Activitate";
        string[] paramNames = values.Select((s, i) => "@val" + i.ToString()).ToArray();

        string inClause = string.Join(",", paramNames);
        using (var cmd = new SqlCommand(string.Format(sqlQuery, inClause), conn))
        {
            for (int i = 0; i < paramNames.Length; i++)
            {
                cmd.Parameters.AddWithValue(paramNames[i], values[i]);
            }
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            conn.Open();
            DataSet ds = new DataSet();
            da.Fill(ds);
            DataList1.DataSource = ds.Tables[0];
            DataList1.DataBind();
            conn.Close();
        }
    }
    
}

Change string array to list of string. I have updated my answer.

Thank you Jignesh,

I implemented your solution and I have the following error

public  List values = new List;
protected void btnAddClick(object sender, EventArgs e)
{
    
    if(!string.IsNullOrEmpty(txtActivitate.Text))
    {
      values.Add(txtActivitate.Text.ToString())
    }

    for (int i = 0; i < values.Count; i++)
    {

        Message.Text += values[i] + "
";

    }
}

Please try above one it should work, you are creating new object of string array so existing values will read off.

The problem I have is that string values is not passed to select query. I modified a little the select method to

protected void btnSelectClick(object sender, EventArgs e)
{
    List values = new List { "Tehnician", "Inginer" };
    using (SqlConnection conn = new SqlConnection(connString))
    {
        string sqlQuery = "SELECT * FROM tblActivitate t1 JOIN tblEvaris t2 ON t1.AID = t2.AID JOIN tblMasura t3 on t2.EID = t3.EID WHERE t1.Activitate IN ({0}) ORDER BY Activitate";
        string[] paramNames = values.Select((s, i) => "@val" + i.ToString()).ToArray();

        string inClause = string.Join(",", paramNames);
        using (var cmd = new SqlCommand(string.Format(sqlQuery, inClause), conn))
        {
            for (int i = 0; i < paramNames.Length; i++)
            {
                cmd.Parameters.AddWithValue(paramNames[i], values[i]);
            }
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            conn.Open();
            DataSet ds = new DataSet();
            da.Fill(ds);
            DataList1.DataSource = ds.Tables[0];
            DataList1.DataBind();
            conn.Close();
        }
    }
}

and is working. But if I try to get parameters from 

readonly string[] values;
protected void btnAddClick(object sender, EventArgs e)
{
    List values = new List
    {
        txtActivitate.Text.ToString() + ","
    };

    for (int i = 0; i < values.Count; i++)
    {

        Message.Text += values[i] + "
";

    }
}

I got empty values. Why?