CODEWITHSUNDEEP
c#asp.netlinqgridview
SUPER_USER
SUPER_USER

Reputation: 273

grid data according to drop down value

I have drop down and grid view..i fill drop down from database like this

There is two table tblReg and tblRes both have RegionID

 protected void Page_Load(object sender, EventArgs e)
        {
            T1 tea = new T1();
            var list1 = tea.tblReg.ToList();
            var list = (from ta in list1
                        let data = ta.Region + " " + ta.StartDate ?? DateTime.Now.ToString() + " " + ta.EndDate ?? DateTime.Now.ToString()
                        select new { data, ta.RegionID }).ToList();

            if(!Page.IsPostBack)
            {
                regiondrop.DataSource = list;
                regiondrop.DataTextField = "data";
                regiondrop.DataValueField = "RegionID";
                regiondrop.DataBind();

            }
    }

now there is several values in drop down and i want when i select value from drop down then again to this value data will be display

On dropdown SelectedIndexChange i done this 

 protected void regiondrop_SelectedIndexChanged(object sender, EventArgs e)
    {
        T1 ts = new T1();

        var dq=(from dropdwn in ts.tblRes
               where dropdwn.RegionID==Convert.ToInt32(regiondrop.SelectedValue)
               orderby dropdwn.OwnerName
               select new {
                            FFID = dropdwn.FFID,
                            OwnerName = dropdwn.OwnerName,
                            RegNo = dropdwn.RegNo,
                            RegionID = dropdwn.RegionID,

               });
        GridView1.DataSource = dq;
        GridView1.DataBind();
    }

when i select value from dropdown it shows error

LINQ to Entities does not recognize the method 'Int32 ToInt32(System.String)' method, and this method cannot be translated into a store expression.

on 

GridView1.DataBind();

any solution

Upvotes: 1

Views: 68

Answers (1)

Raphaël Althaus
Raphaël Althaus

Reputation: 60503

Well, as your error mentions, you can't do

Convert.ToInt32(regiondrop.SelectedValue)

in a linq to entities query (it can't be translated in sql / a store expression)

So just change these lines

var dq=(from dropdwn in ts.tblRes
        where dropdwn.RegionID==Convert.ToInt32(regiondrop.SelectedValue)

to

var selectedValue = Convert.ToInt32(regiondrop.SelectedValue);

var dq=(from dropdwn in ts.tblRes
            where dropdwn.RegionID==selectedValue

You could also do (but the previous solution is more readable)

var dq=(from dropdwn in ts.tblRes
            where SqlFunctions.StringConvert((double)dropdwn.RegionID)==regiondrop.SelectedValue

There's a method in SqlFunctions to convert a numeric to a string, but... not a string to a numeric value.

Upvotes: 1

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