public void AlterTable( string schemaName, string tableName, G.List<AlterAction> alist, Exec e )
{
Table t = (Table) GetTable( schemaName, tableName, e );
var names = new G.List<string>( t.Cols.Names );
var types = new G.List<DataType>( t.Cols.Types );
var map = new G.List<int>();
for ( int i = 0; i < names.Count; i += 1 ) map.Add( i );
foreach ( AlterAction aa in alist )
{
int ix = names.IndexOf( aa.Name );
if ( aa.Operation != Action.Add && ix == -1 )
e.Error( "Column " + aa.Name + " not found" );
switch ( aa.Operation )
{
case Action.Add:
if ( ix != -1 ) e.Error( "Column " + aa.Name + " already exists" );
names.Add( aa.Name );
types.Add( aa.Type );
map.Add( 0 );
Sql( "INSERT INTO sys.Column( Table, Name, Type ) VALUES ( " + t.TableId + "," + Util.Quote(aa.Name) + "," + (int)aa.Type + ")" );
break;
case Action.Drop:
names.RemoveAt( ix );
types.RemoveAt( ix );
map.RemoveAt( ix );
Sql( "DELETE FROM sys.Column WHERE Table = " + t.TableId + " AND Name = " + Util.Quote(aa.Name) );
Sql( "EXEC sys.DroppedColumn(" + t.TableId + "," + ix + ")" );
break;
case Action.ColumnRename:
names.RemoveAt( ix );
names.Insert( ix, aa.NewName );
Sql( "UPDATE sys.Column SET Name = " + Util.Quote(aa.NewName) + " WHERE Table=" + t.TableId + " AND Name = " + Util.Quote(aa.Name) );
break;
case Action.Modify:
if ( DTI.Base( aa.Type ) != DTI.Base( types[ ix ] ) )
e.Error( "Modify cannot change base type" );
if ( DTI.Scale( aa.Type ) != DTI.Scale( types[ ix ] ) )
e.Error( "Modify cannot change scale" );
types.RemoveAt( ix );
types.Insert( ix, aa.Type );
Sql( "UPDATE sys.Column SET Type = " + (int)aa.Type + " WHERE Table=" + t.TableId + " AND Name = " + Util.Quote(aa.Name) );
Sql( "EXEC sys.ModifiedColumn(" + t.TableId + "," + ix + ")" );
break;
}
}
var newcols = ColInfo.New( names, types );
t.AlterData( newcols, map.ToArray() );
Sql( "EXEC sys.RecreateModifiedIndexes()" );
t.OpenIndexes();
ResetCache();
}
public TableExpression GetTableOrView( string schemaName, string name, Exec e )
{
Schema schema = GetSchema( schemaName, true, e );
TableExpression result = schema.GetCachedTable( name );
if ( result != null ) return result;
bool isView; string definition;
long tid = ReadTableId( schema, name, out isView, out definition );
if ( tid < 0 ) e.Error( schemaName + "." + name + " not found" );
if ( isView )
{
TableExpression te = e.LoadView( definition, schemaName + "." + name );
te.TableId = tid;
schema.TableDict[ name ] = te;
return te;
}
else
{
// Fetch the Column Information from the SysColumn table.
var names = new G.List<string>();
var types = new G.List<DataType>();
names.Add( "Id" ); types.Add( DataType.Bigint ); // Add the pre-defined "id" column.
// Use SysColumnIndex to avoid scanning the entire SysColumn table.
var start = new LongStart( tid );
var r = new RowCursor( SysColumn );
foreach( IndexFileRecord ixr in SysColumnIndex.From( start.Compare, false ) )
{
if ( ixr.Col[0].L == tid )
{
r.Get( ixr.Col[1].L );
names.Add( (string) r.V[2]._O );
types.Add( (DataType)r.V[3].L );
}
else break;
}
Table t = new Table( this, schema, name, ColInfo.New(names,types), tid );
t.OpenIndexes();
return t;
}
}
public ColInfo Get()
{
ColInfo result = ColInfo.New( Names, Types );
Names = null;
return result;
}
