private void CheckJoinCondition(SqlExpression expr)
{
switch (expr.NodeType)
{
case SqlNodeType.And: {
SqlBinary b = (SqlBinary)expr;
CheckJoinCondition(b.Left);
CheckJoinCondition(b.Right);
break;
}
case SqlNodeType.EQ:
case SqlNodeType.EQ2V: {
SqlBinary b = (SqlBinary)expr;
SqlColumnRef crLeft = b.Left as SqlColumnRef;
SqlColumnRef crRight = b.Right as SqlColumnRef;
if (crLeft != null && crRight != null)
{
SqlColumn cLeft = crLeft.GetRootColumn();
SqlColumn cRight = crRight.GetRootColumn();
this.map[cLeft] = cRight;
this.map[cRight] = cLeft;
}
break;
}
}
}
internal bool AreEquivalent(SqlExpression e1, SqlExpression e2)
{
if (SqlComparer.AreEqual(e1, e2))
{
return(true);
}
SqlColumnRef cr1 = e1 as SqlColumnRef;
SqlColumnRef cr2 = e2 as SqlColumnRef;
if (cr1 != null && cr2 != null)
{
SqlColumn c1 = cr1.GetRootColumn();
SqlColumn c2 = cr2.GetRootColumn();
SqlColumn r;
return(this.map.TryGetValue(c1, out r) && r == c2);
}
return(false);
}