sql - how to query a dataset in c# -

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this first post, please gentle :)

i'm working on automatic register university project. use rfid scanner scan student id tag , db created in access. use c# , datagridview show db tables.

i trying write sql query return current sessionid each scanned tagid, compering date/time saved in db current date/time. question is: how do it? have googled problem not find answer looking (probably due complicated structure of tables). maybe able help.

my tables structured followed:

student fields name -> data type ========================= (pk) tagid -> number studentid -> text (fk) courseid -> number studentname -> text  course ========================= (pk) courseid -> number coursename -> text  coursemodule ========================= (fk) courseid -> number (fk) moduleid -> text  module ========================= (pk) moduleid -> text coursename -> text  modulesession ========================= (fk) moduleid -> text (fk) sessionid -> text  session ========================= (pk) sessionid -> text sessionstartdate -> date sessiontimestart -> time sessiontimeend -> time  attendance ========================= (fk) tagid -> number (fk) sessionid -> text (fk) scanningtime -> date/time

i not sure want. here basic database querying c#.

use dataadapters populate datatables sql query.

            using (sqlconnection conn = connection)             {                 conn.open();                 using (sqlcommand cmd = conn.createcommand())                 {                     cmd.commandtext = @"select *                                         [your tables]                                         tagid = @tagid";                      cmd.parameters.add(new sqlparameter("@tagid", sqldbtype.uniqueidentifier) { value = variablename});                      using (sqldataadapter adapter = new sqldataadapter(cmd))                     {                         dataset dataset = new dataset();                         adapter.fill(dataset, "datatablename");                          return dataset.tables["datatablename"];                     }                 }             }

then can values datatable looping through or using lambda functions

or can bind datatable gridview using gridview properties

what want datatable not sure.


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