ningde_elec_meter/DataBase.MySql.Tool/DBTool.cs

using Microsoft.EntityFrameworkCore;
using Monitor.Models;

namespace DataBase.MySql.Tool
{
    public sealed class DBTool
    {
        private static readonly Lazy<DBTool> MLazy = new Lazy<DBTool>(() => new DBTool());

        public static DBTool Instance => MLazy.Value;

        private AsyncLocal<MyDbContext> _dbContext = new AsyncLocal<MyDbContext>();

        private DBTool()
        {
        }

        public MyDbContext MyDbContext()
        {
            MyDbContext? myDbContext = _dbContext.Value;
            if (myDbContext == null)
            {
                DbContextOptionsBuilder<MyDbContext> optionsBuilder = new DbContextOptionsBuilder<MyDbContext>();
                optionsBuilder.UseMySQL<MyDbContext>(
                    "Data Source=localhost;Initial Catalog=chassis_track_swap;User ID=root;Password=123456;sslmode=none;");
                myDbContext = new MyDbContext(optionsBuilder.Options);
            }

            _dbContext.Value = myDbContext;
            return myDbContext;
        }
    }
}