一击从 sql server 获取所有组合值

Question

On my page i have multiple combos/dropdown in one screen and all the combos/dropdown are loading data from SQL. for example if there is 20 combo then 20 time database would be called to fetch data in one request. Is there any way to get all combos data in one SQL hit?

Answer 1

Atually it is possible to return two (or more) datatables from stored procedure (I'm talking about MS SQL)

Something like

create procedure SampleDataSetResult
as
begin
 select * from table1
 select * from table2
end

Then this can be consumed like

var command = new SqlCommand();
command.CommandType = CommandType.StoredProcedure;
command.CommandText = "SampleDataSetResult";
using (SqlDataAdapter da = new SqlDataAdapter(command))
{
    DataSet dataset = new DataSet();
    da.Fill(dataset);

    // here you can use dataset tables
}

However this approach works with raw data from database. Also it contains datatables that do not have names to be analyzed. The only one is to synchronize datatable index between SP and source code and process this datatable data according to its index. Like dataset.Tables[0] - is treated like combo data 1 etc. This can be tricky and all SP modifications have to be synchronized with source code. Also having 20 combos on one page sounds a little bit strange. I suppose that there will be combos data to be shown that depends from data selected in the previous combo.

I do not see any reason to save SQL queries count right now for you. If you have web page then you can try to use MVC approach and wrap database calls with view model method calls.