基于SqlSugar的开发框架循序渐进介绍（4）-- 在数据访问基类中对GUID主键进行自动赋值处理

    [Serializable]
    public abstract class Entity<TPrimaryKey> : IEntity<TPrimaryKey>
    {
        /// <summary>
        /// 实体类唯一主键
        /// </summary>
        [SqlSugar.SugarColumn(IsPrimaryKey = true, ColumnDescription = "主键")]
        public virtual TPrimaryKey Id { get; set; }

    [Serializable]
    public abstract class Entity : Entity<int>, IEntity
    {
        /// <summary>
        /// ID 主键，自增长类型
        /// </summary>
        [SqlSugar.SugarColumn(IsPrimaryKey = true, IsIdentity = true)]
        public override int Id { get; set; }
    }

    /// <summary>
    /// 客户信息
    /// 继承自Entity，拥有Id主键属性
    /// </summary>
    [SugarTable("T_Customer")]
    public class CustomerInfo : Entity<string>
    {
        /// <summary>
        /// 默认构造函数（需要初始化属性的在此处理）
        /// </summary>
        public CustomerInfo()
        {
            this.Id = System.Guid.NewGuid().ToString();
            this.CreateTime = System.DateTime.Now;

        }

    /// <summary>
    /// 客户信息
    /// 继承自Entity，拥有Id主键属性
    /// </summary>
    [SugarTable("T_Customer")]
    public class CustomerInfo : Entity<string>
    {
        /// <summary>
        /// 默认构造函数（需要初始化属性的在此处理）
        /// </summary>
        public CustomerInfo()
        {
            this.CreateTime = System.DateTime.Now;
        }

        /// <summary>
        /// 创建对象
        /// </summary>
        /// <param name="input">实体对象</param>
        /// <returns></returns>
        public virtual async Task<bool> InsertAsync(TEntity input)
        {
            return await EntityDb.InsertAsync(input); 
        }

        /// <summary>
        /// 创建对象
        /// </summary>
        /// <param name="input">实体对象</param>
        /// <returns></returns>
        public virtual async Task<bool> InsertAsync(TEntity input)
        {
            SetIdForGuids(input);//如果Id为空，设置有序的GUID值
            return await EntityDb.InsertAsync(input); 
        }

        /// <summary>
        /// 为新创建的实体对象，设置主键Id的值为有序的GUID值（GUID类型或者字符串类型试用）
        /// </summary>
        public virtual void SetIdForGuids(TEntity entity)
        {
            if (entity is IEntity<Guid> entityWithGuidId && entityWithGuidId.Id == Guid.Empty)
            {
                //默认的GUID类型
                var guidType = SequentialGuidType.SequentialAsString;

                switch(this.dbContext.DbType) //根据不同的数据库类型获取合适的生成序列方式
                {
                    case SqlSugar.DbType.SqlServer:
                        guidType = SequentialGuidType.SequentialAtEnd;
                        break;
                    case SqlSugar.DbType.MySql:
                    case SqlSugar.DbType.PostgreSQL:
                        guidType = SequentialGuidType.SequentialAsString;
                        break;
                    case SqlSugar.DbType.Oracle:
                        guidType = SequentialGuidType.SequentialAsBinary;
                        break;
                }

                var guid = GetSequentialGuid(guidType);
                entityWithGuidId.Id = guid;
            }
            else if (entity is IEntity<string> entityWithStringId && string.IsNullOrWhiteSpace(entityWithStringId.Id))
            {
                var guid = GetSequentialGuid(SequentialGuidType.SequentialAsString);
                entityWithStringId.Id = guid.ToString();
            }
        }

        /// <summary>
        /// 获取可以生成连续的GUID
        /// </summary>
        /// <returns></returns>
        protected Guid GetSequentialGuid(SequentialGuidType sequentialGuidType)
        {//使用指定序列创建的（生成连续的GUID）
            //参考链接了解细节：(https://github.com/abpframework/abp/blob/48c52625f4c4df007f04d5ac6368b07411aa7521/docs/zh-Hans/Guid-Generation.md)
            var options = new AbpSequentialGuidGeneratorOptions()
            {
                DefaultSequentialGuidType = sequentialGuidType
                //SequentialAtEnd(default) 用于SQL Server.
                //SequentialAsString 用于MySQL和PostgreSQL.
                //SequentialAsBinary 用于Oracle.
            };
            return new SequentialGuidGenerator(options).Create();
        }