C#

public class Class

Pete O'Hanlon wrote:

It gets fun if you try and consume it in a language like VB.NET though.

Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
"If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.

using Microsoft.AspNet.OData;
using Microsoft.AspNet.OData.Routing;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Oyg.Domain.DataTypes;
using System;
using System.Linq;
using System.Threading.Tasks;

namespace Oyg.Api.Controllers
{
    public partial class ClassesController : ODataController
    {
        /// <summary>
        /// Get all bookings. Get the class reservation queue.
        /// </summary>
        /// <returns></returns> 
        [HttpGet]
        [ODataRoute("Classes({classId})/Bookings")]
        public async Task<IActionResult> GetBookings([FromODataUri] Guid classId)
        {
            return Ok(await _context.Bookings
                .Where(y => y.Class.Id == classId)
                .ToListAsync());
        }

        /// <summary>
        /// Get a specific booking
        /// </summary>
        /// <returns></returns>
        [HttpGet]
        [ODataRoute("Classes({classId})/Bookings({bookingId})")]
        public async Task<IActionResult> GetBooking([FromODataUri] Guid classId, [FromODataUri] Guid bookingId)
        {
            var @class = await _context.Classes.FirstOrDefaultAsync(y => y.Id == classId);

            if (@class == null)
            {
                return NotFound();
            }

            var booking = _context.Bookings.Where(y => y.Class.Id == classId && y.Id == bookingId);

            if (!booking.Any())
            {
                return NotFound();
            }

            return Ok(SingleResult.Create(booking));
        }

        /// <summary>
        /// Add a booking reservation in a class
        /// </summary>
        /// <param name="class"></param>
        /// <returns></returns>
        [HttpPost]
        [ODataRoute("Classes({classKey})/Bookings")]
        public async Task<IActionResult> PostBooking([FromODataUri] Guid classKey, [FromBody] Booking booking)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            var @class = _context.Classes
                .FindAsync(classKey);

            if (@class == null)
            {
                return NotFound();
            }

            booking.Id = Guid.NewGuid();
            booking.Position = _context.Bookings.Where(y => y.Class.Id == classKey).Count();
            booking.ReservationTime = DateTime.UtcNow;

            _context.Bookings.Add(booking);
            await _context.SaveChangesAsync();
            return Created(booking);
        }

        ///// <summary>
        ///// DELETE: api/Classes/5
        ///// </summary>
        ///// <param name="id"></param>
        ///// <returns></returns>
        //[HttpDelete()]
        //[ODataRoute("Classes({classKey})/Bookings({key})")]
        //public async Task<IActionResult> DeleteBooking([FromODataUri] Guid classKey, [FromODataUri] Guid key)
        //{
        //    var @class = await _context.Classes.FindAsync(classKey);

        //    if (@class == null)
        //    {
        //        return NotFound();
        //    }

        //    var booking = await _context.Bookings.FindAsync(key);

        //    if (booking == null)
        //    {
        //        return NotFound();
        //    }

        //    booking.CancelTime = DateTime.UtcNow;
        //    await _context.SaveChangesAsync();

        //    return Ok(@class);
        //}

        [HttpPost]
        [ODataRoute("Classes({classKey})/Oyg.Actions.Register")]
        public async Task<IActionResult> Register([FromODataUri] Guid classKey, ODataActionParameters parameters)
        {
            var @class = await _context.Classes.FindAsync(classKey);

            if (@class == null)
            {
                return NotFound();
            }

            if (!parameters.TryGetValue("studentId", out object outputFromDictionary))
            {
                return NotFound();
            }

            if (!Guid.TryParse(outputFromDictionary.ToString(), out Guid studentId))
            {
                return NotFound();
            }

            // the student must exist
            var student = await _context.Students.FirstOrDefaultAsync(y => y.Id == studentId);

            if (student == null)
            {
                return NotFound();
            }

            var booking = new Booking()
            {
                Id = Guid.NewGuid(),
                Class = @class,
                Student = student,
                Position = _context.Bookings.Where(y => y.Class.Id == classKey).Count(),
                ReservationTime = DateTime.UtcNow
            };

            _context.Bookings.Add(booking);
            await _context.SaveChangesAsync();
            // return true
            return Ok(booking);
        }

        [HttpPost]
        [ODataRoute("Classes({classKey})/Oyg.Actions.CancelRegistration")]
        public async Task<IActionResult> CancelRegistration([FromODataUri] int classKey, ODataActionParameters parameters)
        {
            var @class = await _context.Classes.FindAsync(classKey);

            if (@class == null)
            {
                return NotFound();
            }

            if (!parameters.TryGetValue("studentId", out object outputFromDictionary))
            {
                return NotFound();
            }

            if (!Guid.TryParse(outputFromDictionary.ToString(), out Guid studentId))
            {
                return NotFound();
            }

            // the student must exist
            var student = _context.Students.FirstOrDefault(y => y.Id == studentId);

            if (student == null)
            {
                return NotFound();
            }

            var booking = await _context.Bookings.SingleOrDefaultAsync(y => y.Class.Id == @class.Id &&
                y.Student.Id == student.Id && y.CancelTime == null);

            if (booking == null)
            {
                return NotFound();
            }

            booking.CancelTime = DateTime.UtcNow;
            await _context.SaveChangesAsync();

            return NoContent();
        }
    }
}

Number of query values and destination fields are not the same.

com.CommandText = "INSERT INTO Kharid_Detail(" + dt.Columns[i].ColumnName.Trim() + ")VALUES(" + (i++) + ",'" +
dt.Rows[i].ItemArray.GetValue(i) + "')";

com.CommandText = "INSERT INTO Kharid_Detail(" + x + ")VALUES(" + y + ",'" + z + "')";

"<pre>System.Data.OleDb.OleDbException: 'You must enter a value in the 'Kharid_Detail.KalaKhadamatName' field.'

<pre>for (int j = 0; j < (TtmsdataGridView.ColumnCount); j++)

                    for (int i = 0; i < (TtmsdataGridView.Rows.Count); i++)
                    {
                        com.CommandText = "INSERT INTO Kharid_Detail(" + TtmsdataGridView.Columns[j].Name.Trim() + ")VALUES(" + TtmsdataGridView.Rows[i].Cells[j].Value + ")";

                        com.ExecuteNonQuery();
                    }

SELECT * FROM MyTable WHERE StreetAddress = 'Baker's Wood'

SELECT * FROM MyTable WHERE StreetAddress = 'x';DROP TABLE MyTable;--'

SELECT * FROM MyTable WHERE StreetAddress = 'x';

DROP TABLE MyTable;

--'