(C#) How to query multiple conditions in one page

dennick

I set up query conditions with four DropDownLists in one page, but how do I write the code? Is it too cumbersome to use IF? Please advise me

xing_532

If you want to judge, only IF and Switch...Case

my_veigh

if (this.Drpcondition.SelectedIndex> 0)
        {
            string cdition = this.Drpcondition.SelectedValue;
            string Condition="";

            switch (cdition)
            {
                case "Post user":
                    Condition = "select * from MQ_ALlPhoto where UserName like'%" + this.txtcondotion.Text.Trim() + "%'";
              
                    break;

                case "title":
                    Condition = "select * from MQ_ALlPhoto where Topic like'%" + this.txtcondotion.Text.Trim() + "%'";
                 
                    break;

         
            }
}

freeamway

Suck with or
select * from ... where ...like ... or like .... or like ..... or like ...

nvidia

Jump statements such as if or switch are basically indispensable.
Generally, all query conditions are read into a class, a dynamic string is added to a pseudo SQL statement, and the dynamic string is finally included in the SQL statement according to the judgment condition.

dennick

Thank you, everyone, now I use "select * from ... where ...like ... and like .... and like ....." to achieve.
But there is a new problem: how to implement fuzzy query if there is no choice?

sunray

The value of dropdownlist is an arraylist object, the key value. You can set the value of the first option as the default query condition.

zjjhjjordan

You can make them mandatory, otherwise they will not be executed