how to populate multiple combo boxes

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Hi I have 6 comboboxes and a button. I also have two tables in my sql database.
First of all i have displayed all the tables in cb1 using:

SQL

SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES ORDER BY TABLE_NAME ASC

The Columns of these two tables are exactly the same BUT they do have different records.
Now i wanna populate the remaining 5 comboboxes(cb2,cb3,cb4,cb5 & cb6) each with a column from the tables in the database
(PrdtName, PrdtCat, Origin, Price, Transtype, Continent)
Afterwards i wanna choose a tbl (dynamic)in cb1 and then selects the column names from the other comboboxes and then display its records on button click.
Here my code so far: 1. stored procedure (this also changes depending on the column name)

SQL

 SELECT DISTINCT [PrdtName] FROM ' + @TableName + ' WHERE [Continent] = ''AF''' +
' ORDER BY [PrdtName] ASC

2. my c# code. This code repeats 5 times depending on the combobox or the column name

C#

 private void FillcbPrdtName()
{

    string S = ConnectionString;
    SqlConnection cn = new SqlConnection(S);
    SqlCommand cmd = new SqlCommand();
    cmd.Connection = cn;
    cmd.CommandText = ("[dbo].[spPrdtName]");
    cmd.CommandType = CommandType.StoredProcedure;
    cmd.Parameters.AddWithValue("@Table_Name", cb2.SelectedValue.ToString());

    if (cbTbl.SelectedValue != null)
    {
        try
        {
            // Open connection

            cn.Open();
            //Read Data only from DB into the cb
            SqlDataReader name= cmd.ExecuteReader();
            while (name.Read())
            {
                cb2.Items.Add(name["PrdtName"]);
            }
            cb2.SelectedIndex = -1;

        }


        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
        finally
        {
            cn.Close();
        }
    }

There is no ERROR but the 5 comboboxes aren' getting any columns from the database.

Help!!!

Posted 12-Nov-14 2:22am

mikybrain1

Updated 12-Nov-14 22:28pm

v4

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Comments

Dusara Maulik 12-Nov-14 8:36am

In FillcbPrdtName() function, you are taking selection value of cbTopprojekt drop down and also adding items to the same drop down "cbTopprojekt"?

mikybrain1 12-Nov-14 8:43am

updated my question. was a mistake

[no name] 12-Nov-14 9:57am

Why would you tell the user what your tables names are or allow them to select the table names at all?

You should know what the table names are and what data is in them, and let the user select an entry based on your where clause. Why are you doing it this way?

mikybrain1 12-Nov-14 12:25pm

yeah i understand u but i need help now about this problem if u can help

[no name] 12-Nov-14 15:13pm

private void Button5_Click(object sender, EventArgs e)
{
SqlConnection sqlConn = default(SqlConnection);
//Creates a SQL Connection should one be called
string SqlConnectionString = "Your connection string here.";
string Query = null;
sqlConn = new SqlConnection();
sqlConn.ConnectionString = SqlConnectionString;
Query = "SELECT `id` FROM `your_db_name`.`your_table` WHERE `username` = @username AND `password` = @password;";

//Providing the username and password are found in the database,
//It will return an Id number if your table has an Id field.
//The QueryComCheck is combining the query and connection as a command.
SqlCommand QueryComCheck = new SqlCommand(Query, sqlConn);
//Define a variable to return the Id to:
int SelectID = 0;
//Define the username and password:
string UsersUsername = "Bob";
string UsersPass = "TestPass";
//The below shows how parameters can be used as placeholders when
//Executing a query statement.
QueryComCheck.Parameters.AddWithValue("@username", UsersUsername);
QueryComCheck.Parameters.AddWithValue("@password", UsersPass);
//The below statement will check your connection state, and
//open it accordingly if needed.
if (sqlConn.State == ConnectionState.Closed) {
sqlConn.Open();
}
//Here we make use of a reader to read and execute our Query command.
using (SqlDataReader reader = QueryComCheck.ExecuteReader) {
//Has Rows will return False if there is nothing to read.
if (reader.HasRows) {
//If there is something to read, the reader will continue reading.
//If there is nothing to read, the reader returns False by default.
while (reader.Read()) {
//Here you can check if the Id has been found based on our Where clause
//in our query string. If the username and password are a match and the
//Id exists, then you can receive the result here.
if (Convert.ToBoolean(reader.GetString("id")) == true) {
//Now set it to a variable or do what you want with that result.
SelectID = Convert.ToInt32(reader.GetString("id"));
//If you want additional checks for other values, add an ElseIf extension
//to this section of the If Statement.
}
}
}
}
//All done, if there are any mistakes, or errors, you will need to debug
//them yourself, as this was originally for MySQL, and I just changed everything to
//SQL. But in a nutshell, that's more or less how you would do it.
//If you 'have any questions, I can try to answer them for you. Hope it helps.

}

mikybrain1 13-Nov-14 2:47am

I don't have any id and am a lili' bit confused. Can't u please illustrate based on my question?

[no name] 13-Nov-14 9:35am

I will not do this for you. You need to show some effort and research query building and the code I have given you. (PrdtName, PrdtCat, Origin, Price, Transtype, Continent) <<< they belong in your WHERE clause. I used ID because I wanted to illustrate how to get the ID from the ID field. My example demonstrates how you can do this if you Research SQL Select Statements.

Look at your statement: SELECT DISTINCT [PrdtName] FROM ' + @TableName + ' WHERE
Now compare it to what I gave you. Further Education.

mikybrain1 14-Nov-14 2:57am

Thnx man for the encouragement. I appreciate that :)

[no name] 14-Nov-14 10:19am

You're welcome. If you get stuck along the way, just post back, and I will be happy to help you. :)

gggustafson 13-Nov-14 16:26pm

I think you are being hasty (if not discourteous) in trying to read into the requirements. You should not ask "Why are you doing it this way?" unless you have reason to believe that the OP doesn't know the requirements!

I have written software that allowed users to modify the contents of "code tables" - those that contain codes and their meanings (e.g., AZ Arizona) without the need for the user to execute SQL or be knowledgeable of a database structure. Displaying table names and column names was key to the solution.

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