Getting table schema from a query

Posted by Appu on Stack Overflow See other posts from Stack Overflow or by Appu
Published on 2010-06-17T05:36:19Z Indexed on 2010/06/17 5:43 UTC
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As per MSDN, SqlDataReader.GetSchemaTable returns column metadata for the query executed. I am wondering is there a similar method that will give table metadata for the given query? I mean what tables are involved and what aliases it has got.

In my application, I get the query and I need to append the where clause programically. Using GetSchemaTable(), I can get the column metadata and the table it belongs to. But even though table has aliases, it still return the real table name. Is there a way to get the aliase name for that table?

Following code shows getting the column metadata.

const string connectionString = "your_connection_string";
string sql = "select c.id as s,c.firstname from contact as c";

using(SqlConnection connection = new SqlConnection(connectionString))
using(SqlCommand command = new SqlCommand(sql, connection))
{
    connection.Open();
    SqlDataReader reader = command.ExecuteReader(CommandBehavior.KeyInfo);
    DataTable schema = reader.GetSchemaTable();
    foreach (DataRow row in schema.Rows)
    {
        foreach (DataColumn column in schema.Columns)
        {
            Console.WriteLine(column.ColumnName + " = " + row[column]);
        }
        Console.WriteLine("----------------------------------------");
    }
    Console.Read();
}

This will give me details of columns correctly. But when I see BaseTableName for column Id, it is giving contact rather than the alias name c. Is there any way to get the table schema and aliases from a query like the above?

Any help would be great!

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