ESIM/EsimLao/Database/DbLogic.cs

using System.Data;
using Database.Database;
using Microsoft.EntityFrameworkCore;

namespace Database;

public class DbLogic
{
    public static async Task<int?> GenIdAsync(ModelContext dbContext, string sequence)
    {
        var conn = dbContext.Database.GetDbConnection();
        if (conn.State == ConnectionState.Closed)
        {
            await conn.OpenAsync();
        }
        var command = conn.CreateCommand();
        string query = "select " + sequence + ".nextval from dual";
        command.CommandText = query;
        var reader = await command.ExecuteReaderAsync();
        while (await reader.ReadAsync())
        {
            var title = reader.GetString(0);

            //await conn.CloseAsync();
            return int.Parse(title);
        }

        //await conn.CloseAsync();
        return 0;
    }
}