(C#) Flatten DataSet to DataTable

Starting with a valid DataSet:

DataSet s = new DataSet();
s.ReadXml(@"C:\orders.xml");

Add table name to all columns that aren't used for binding ...

foreach(DataTable table in s.Tables) {
foreach (DataColumn column in table.Columns)
{
if(!column.ColumnName.Contains("_Id")) column.ColumnName = table.TableName + "." + column.ColumnName;
}
}

Now join all using David M.'s great DataTable Join function (over at http://weblogs.sqlteam.com/davidm/archive/2004/01/20/748.aspx):

DataTable t = s.Tables[s.Relations[0].ChildTable.TableName];
foreach (DataRelation r in s.Relations)
{
t = Join(s.Tables[r.ParentTable.TableName], t, r.ParentColumns[0].ColumnName, r.ChildColumns[0].ColumnName);
}

List removeColumns = new List();
foreach (DataColumn c in t.Columns) if (c.ColumnName.Contains("_Id")) removeColumns.Add(c.ColumnName);
foreach (string cName in removeColumns) t.Columns.Remove(cName);

Pretty easy, huh ;)

Import MySQL databases with foreign keys

When importing large MySQL databases with lots of tables that have foreign key constrains (such as in our application framework RedOne), these constraints often interfere with each other. So ...

SET FOREIGN_KEY_CHECKS = 0;

... then dump, and afterwards ...

SET FOREIGN_KEY_CHECKS = 1;

... tadaa! :)