private static ISqlConstraint AppendWhere(ISqlConstraint old, ISqlConstraint newConstraint)
{
if (old != null)
{
newConstraint = new SqlBinaryConstraint
{
Left = old,
Opeartor = SqlBinaryConstraintType.And,
Right = newConstraint
};
}
return(newConstraint);
}
protected override SqlBinaryConstraint VisitSqlBinaryConstraint(SqlBinaryConstraint node)
{
var leftBinary = node.Left as SqlBinaryConstraint;
var rightBinary = node.Right as SqlBinaryConstraint;
var isLeftOr = leftBinary != null && leftBinary.Opeartor == SqlBinaryConstraintType.Or;
var isRightOr = rightBinary != null && rightBinary.Opeartor == SqlBinaryConstraintType.Or;
switch (node.Opeartor)
{
case SqlBinaryConstraintType.And:
if (isLeftOr)
{
_sql.Append("(");
}
this.Visit(node.Left);
if (isLeftOr)
{
_sql.Append(")");
}
_sql.AppendAnd();
if (isRightOr)
{
_sql.Append("(");
}
this.Visit(node.Right);
if (isRightOr)
{
_sql.Append(")");
}
break;
case SqlBinaryConstraintType.Or:
this.Visit(node.Left);
_sql.AppendOr();
this.Visit(node.Right);
break;
default:
throw new NotSupportedException();
}
return(node);
}