Multiple conditions in If Else in C#

Question

Hello

 

I have four Dropdownlist and i want to show data in gridview.

when i select from ddlCategory[Dropdownlist] is not Null and other dropdown are null then i want to show only one category that time else return all the category.

But its showing all the category in if condition..plz help

 

 

 

con.Open();

if (ddlCategory.SelectedValue != "" && ddlSubCategory.SelectedItem.Text == "" && ddlBrand.SelectedItem.Text == "" && ddlItem.SelectedItem.Text == "")

{

SqlCommand cmd = new SqlCommand("select Distinct Category from tblMatCat where Category = @Category ", con);

cmd.Parameters.AddWithValue("@Category", ddlCategory.SelectedItem.Text);

SqlDataAdapter da = new SqlDataAdapter(cmd);

da.Fill(dt);

}

else

{

SqlCommand cmd = new SqlCommand("select Distinct Category from tblMatCat ", con);

SqlDataAdapter da = new SqlDataAdapter(cmd);

da.Fill(dt);

}