protected override Expression VisitIsNull(DbIsNullExpression isnull)
{
this.VisitValue(isnull.Expression);
this.Write(" IS NULL");
return(isnull);
}
protected DbIsNullExpression UpdateIsNull(DbIsNullExpression isnull, Expression expression)
{
if (expression != isnull.Expression)
{
return(new DbIsNullExpression(expression));
}
return(isnull);
}
protected Expression MakeIsNull(Expression expression, bool negate)
{
var isnull = new DbIsNullExpression(expression) as Expression;
if (negate == false)
{
return(isnull);
}
return(Expression.Not(isnull));
}
protected virtual bool CompareIsNull(DbIsNullExpression a, DbIsNullExpression b)
{
return(this.Compare(a.Expression, b.Expression));
}
protected virtual Expression VisitIsNull(DbIsNullExpression isnull)
{
return(this.UpdateIsNull(isnull, this.Visit(isnull.Expression)));
}