Question

I am trying to select all (*) the data columns on one table accompanied by INNER JOINing another table to get the menu item name. Please have a look at my query

string query = "SELECT ol.*, m.menu_name " +
                "FROM orderlist ol " +
                "INNER JOIN menudb m " +
                "ON m.menu_ID = ol.menu_ID " +
                "WHERE ol.order_ID = @orderID";

I can’t seem to get the m.menu_name when I retrieve it using dr["menu_name"].ToString()

Any ideas why?

orderlist Table Columns

orderlist_ID order_ID menu_ID order_quantity

menudb Table Columns

menu_ID menu_name menu_price menu_description menu_category menu_status

Answer 1

There are many problems in your query.

First, you have a syntax error due to lack of spaces between keywords.

"ON m.menu_ID = ol.menu_ID" +     // << HERE
"WHERE ol.order_ID = '@orderID'";

you should have add an extra space after ol.menu_ID

"ON m.menu_ID = ol.menu_ID " +
"WHERE ol.order_ID = '@orderID'";

Second, if you parameterized the query, you should not wrap the parameter with a single quote. This causes to be a string and not a parameter anymore.

"WHERE ol.order_ID = @orderID"; // remove single quote