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abstract private Optimize ( ) : |
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| Résultat | ||
/// <include file='doc\DataExpression.uex' path='docs/doc[@for="DataExpression.Bind"]/*' />
public virtual void Bind(DataTable table)
{
#if DEBUG
if (CompModSwitches.DataExpression.TraceVerbose)
{
Debug.WriteLine("Bind current expression in the table " + (table != null ? table.TableName : "null"));
}
#endif
this.table = table;
if (table == null)
{
return;
}
if (expr != null)
{
Debug.Assert(parsed, "Invalid calling order: Bind() before Parse()");
ArrayList list = new ArrayList();
expr.Bind(table, list);
expr = expr.Optimize();
this.table = table;
optimizedExpression = null;
Debug.Assert(list != null, "Invlid dependency list");
bound = true;
dependency = new DataColumn[list.Count];
list.CopyTo(dependency, 0);
#if DEBUG
if (dependency == null)
{
if (CompModSwitches.DataExpression.TraceVerbose)
{
Debug.WriteLine("no dependencies");
}
}
else
{
if (CompModSwitches.DataExpression.TraceVerbose)
{
Debug.WriteLine("have dependencies: " + dependency.Length.ToString());
}
for (int i = 0; i < dependency.Length; i++)
{
//UNDONE : Debug.WriteLineIf("DataExpression", dependency[i].ColumnName);
}
}
#endif
}
}
internal override ExpressionNode Optimize()
{
_right = _right.Optimize();
if (IsConstant())
{
object val = Eval();
return(new ConstNode(table, ValueType.Object, val, false));
}
else
{
return(this);
}
}
internal void Bind(DataTable table)
{
_table = table;
if (table == null)
{
return;
}
if (_expr != null)
{
Debug.Assert(_parsed, "Invalid calling order: Bind() before Parse()");
List <DataColumn> list = new List <DataColumn>();
_expr.Bind(table, list);
_expr = _expr.Optimize();
_table = table;
_bound = true;
_dependency = list.ToArray();
}
}
internal override ExpressionNode Optimize()
{
left = left.Optimize();
if (op == Operators.Is)
{
// only 'Is Null' or 'Is Not Null' are valid
if (right is UnaryNode)
{
UnaryNode un = (UnaryNode)right;
if (un.op != Operators.Not)
{
throw ExprException.InvalidIsSyntax();
}
op = Operators.IsNot;
right = un.right;
}
if (right is ZeroOpNode)
{
if (((ZeroOpNode)right).op != Operators.Null)
{
throw ExprException.InvalidIsSyntax();
}
}
else
{
throw ExprException.InvalidIsSyntax();
}
}
else
{
right = right.Optimize();
}
#if DEBUG
if (CompModSwitches.BinaryNode.TraceVerbose)
{
Debug.WriteLine("Optimizing " + this.ToString());
}
#endif
if (this.IsConstant())
{
object val = this.Eval();
#if DEBUG
if (CompModSwitches.BinaryNode.TraceVerbose)
{
Debug.WriteLine("the node value is " + val.ToString());
}
#endif
if (val == DBNull.Value)
{
return(new ZeroOpNode(Operators.Null));
}
if (val is bool)
{
if ((bool)val)
{
return(new ZeroOpNode(Operators.True));
}
else
{
return(new ZeroOpNode(Operators.False));
}
}
#if DEBUG
if (CompModSwitches.BinaryNode.TraceVerbose)
{
Debug.WriteLine(val.GetType().ToString());
}
#endif
return(new ConstNode(ValueType.Object, val, false));
}
else
{
return(this);
}
}