Delete from multiple SQL tables with C# command

Question

I want to delete from multiple SQL tables with a C# command but I get always error:

Invalid syntax near ",".

Here is code so far:

string connectionString = @"Data Source=" + System.IO.File.ReadAllText("Server.ini") + ";" + "Initial Catalog=" + "lin2world" + ";" + "User ID=" + System.IO.File.ReadAllText("User.ini") + ";" + "Password=" + System.IO.File.ReadAllText("Password.ini");
string sql = "DELETE FROM user_data, user_item, user_ActiveSkill, user_blocklist, user_deleted, user_friend, user_henna, user_history, user_log, user_macro, user_macroinfo, user_newbie, user_nobless, user_punish, user_recipe, user_skill, user_sociality, user_subjob WHERE char_id='" + textBox1.Text + "' ";
SqlConnection connection = new SqlConnection(connectionString);
SqlDataAdapter dataadapter = new SqlDataAdapter(sql, connection);
DataSet ds = new DataSet();
connection.Open();
dataadapter.Fill(ds, "char_id");
connection.Close();
MessageBox.Show("Character Deleted!!");

Answer 1

You can only delete from one table in a delete statement.

Use multiple delete statements within a transaction to perform the deletes

In case your not familiar with transactions in C# here is an example

using (var Conn = new SqlConnection(_ConnectionString))
{
    SqlTransaction trans = null;
    try
    {
        Conn.Open();
        trans = Conn.BeginTransaction();

        using (SqlCommand Com = new SqlCommand(ComText, Conn, trans))
        {
            /* DB work */
        }
        trans.Commit();
    }
    catch (Exception Ex)
    {
        if (trans != null) trans.Rollback();
        return -1;
    }
}

Answer 2

If you want to do something similar to this, you can pass all tables as a list and still do what you want.

DECLARE db_cursor CURSOR FOR  
SELECT name 
FROM master.dbo.sysdatabases 
WHERE name IN ("user_data","user_item","user_ActiveSkill","user_blocklist","user_deleted","user_friend","user_henna","user_history","user_log","user_macro","user_macroinfo","user_newbie","user_nobless","user_punish","user_recipe","user_skill","user_sociality","user_subjob")  -- use these databases

OPEN db_cursor   
FETCH NEXT FROM db_cursor INTO @name   


WHILE @@FETCH_STATUS = 0   
BEGIN   

       DELETE FROM @name WHERE char_id='whatever'

       FETCH NEXT FROM db_cursor INTO @name   
END   

Edit: It seems like these are all related tables -- if you have a proper relationship with cascade: delete, you should only have to delete the main record and its children will all take care of themselves

Answer 3

You cannot delete from multiple tables in one statement within SQL Server. You will need multiple statements, one for each table:

DELETE FROM user_data WHERE PersonID = '2';
DELETE FROM user_item WHERE PersonID = '2';

etc etc

And fire each one off individually, (making sure not to violate any FKs) or create a stored procedure and fire that off (to minimise open and closing of db connections).

My experience of using triggers tells me not to use triggers, at times they will not fire when they should!