NET7下EFCORE的通用增删查改类 代码摘录自《深入浅出ASP.NET CORE》
/// <summary>
/// 所有仓储的约定，此接口仅作为约定，用于标识他们
/// </summary>
/// <typeparam name="TEntity">传入仓储的实体模型</typeparam>
/// <typeparam name="TPrimaryKey">传入仓储的主键类型</typeparam>
public interface IRepository<TEntity,TPrimaryKey> where TEntity : class
{
#region 查询
IQueryable<TEntity> GetAll();
List<TEntity> GetAllList();
Task<List<TEntity>> GetAllListAsync();
List<TEntity> GetAllList(Expression<Func<TEntity, bool>> predicate);
Task<List<TEntity>> GetAllListAsync(Expression<Func<TEntity, bool>> predicate);
TEntity FirstOrDefault(Expression<Func<TEntity, bool>> predicate);
Task<TEntity> FirstOrDefaultAsycn(Expression<Func<TEntity, bool>> predicate);
#endregion
#region 新增
TEntity Insert(TEntity entity);
Task<TEntity> InsertAsync(TEntity entity);
#endregion
#region 更新
TEntity Update(TEntity entity);
Task<TEntity> UpdateAsync(TEntity entity);
#endregion
#region 删除
void Delete(TEntity entity);
Task DeleteAsync(TEntity entity);
void Delete(Expression<Func<TEntity, bool>> predicate);
Task DeleteAsync(Expression<Func<TEntity, bool>> predicate);
#endregion
#region 总和计算
int Count();
Task<int> CountAsync();
int Count(Expression<Func<TEntity, bool>> predicate);
Task<int> CountAsync(Expression<Func<TEntity, bool>> predicate);
#endregion
}
/// <summary>
/// 默认仓储的通用功能实现，用于所有的领域模型
/// </summary>
/// <typeparam name="TEntity"></typeparam>
/// <typeparam name="TPrimaryKey"></typeparam>
public class RepositoryBase<TEntity, TPrimaryKey> : IRepository<TEntity, TPrimaryKey> where TEntity : class
{
protected readonly AppDbContext _appDbContext;
public RepositoryBase(AppDbContext appDbContext)
{
_appDbContext = appDbContext;
}
public virtual DbSet<TEntity> Table=>_appDbContext.Set<TEntity>();
public int Count()
{
return GetAll().Count();
}
public int Count(Expression<Func<TEntity, bool>> predicate)
{
return GetAll().Where(predicate).Count();
}
public async Task<int> CountAsync()
{
return await GetAll().CountAsync();
}
public async Task<int> CountAsync(Expression<Func<TEntity, bool>> predicate)
{
return await GetAll().Where(predicate).CountAsync();
}
public void Delete(TEntity entity)
{
AttachIfNot(entity);
Table.Remove(entity);
Save();
}
public async Task DeleteAsync(TEntity entity)
{
AttachIfNot(entity);
Table.Remove(entity);
await SaveAsync();
}
public void Delete(Expression<Func<TEntity, bool>> predicate)
{
foreach (var entity in GetAll().Where(predicate).ToList())
{
Delete(entity);
}
}
public async Task DeleteAsync(Expression<Func<TEntity, bool>> predicate)
{
foreach (var entity in GetAll().Where(predicate).ToList())
{
await DeleteAsync(entity);
}
}
public TEntity FirstOrDefault(Expression<Func<TEntity, bool>> predicate)
{
return GetAll().FirstOrDefault(predicate);
}
public async Task<TEntity> FirstOrDefaultAsycn(Expression<Func<TEntity, bool>> predicate)
{
return await GetAll().FirstOrDefaultAsync(predicate);
}
public IQueryable<TEntity> GetAll()
{
return Table.AsQueryable();
}
public List<TEntity> GetAllList()
{
return GetAll().ToList();
}
public List<TEntity> GetAllList(Expression<Func<TEntity, bool>> predicate)
{
return GetAll().Where(predicate).ToList();
}
public async Task<List<TEntity>> GetAllListAsync()
{
return await GetAll().ToListAsync();
}
public async Task<List<TEntity>> GetAllListAsync(Expression<Func<TEntity, bool>> predicate)
{
return await GetAll().Where(predicate).ToListAsync();
}
public TEntity Insert(TEntity entity)
{
var newEntity = Table.Add(entity).Entity;
Save();
return newEntity;
}
protected void Save()
{
_appDbContext.SaveChanges();
}
protected async Task SaveAsync() {
await _appDbContext.SaveChangesAsync();
}
/// <summary>
/// 检查实体是否处于跟踪状态，如果是，则返回，如果不是，则添加跟踪状态
/// </summary>
/// <param name="entity"></param>
protected virtual void AttachIfNot(TEntity entity) {
var entry = _appDbContext.ChangeTracker.Entries().FirstOrDefault(e => e.Entity == entity);
if (entry != null) { return; }
Table.Attach(entity);
}
public async Task<TEntity> InsertAsync(TEntity entity)
{
var entityEntry = await Table.AddAsync(entity);
await SaveAsync();
return entityEntry.Entity;
}
public TEntity Update(TEntity entity)
{
AttachIfNot(entity);
_appDbContext.Entry(entity).State = EntityState.Modified;
Save();
return entity;
}
public async Task<TEntity> UpdateAsync(TEntity entity)
{
AttachIfNot(entity);
_appDbContext.Entry(entity).State = EntityState.Modified;
await SaveAsync();
return entity;
}
}
//假设有一学生接口需要有额外的登录接口，可新建一个IStudent接口，继承后只用加Login接口就行
public interface IStudentRepository :IRepository<Student, int>
{
bool Login(string username, string password);
}
//实现类除了要实现上面的接口，还要继承基类RepositoryBase
public class StudentRepository : RepositoryBase<Student, int>, IStudentRepository
{
public StudentRepository(AppDbContext appDbContext) : base(appDbContext)
{
}
public bool Login(string username, string password)
{
bool b = false;
//GetAll是基类中的方法，返回 iquerable
b = GetAll().Where(a=>a.username=username && a.password=password).Count()>0
return b;
}
}
//使用记得注入
services.AddTransient(typeof(IRepository<,>), typeof(RepositoryBase<,>));
services.AddTransient<IStudentRepository, StudentRepository>();
//控制器里的代码
private readonly IRepository<Student, int> _studentRepository;
private readonly IStudentRepository _studentRepository2;
public WelcomeController( IRepository<Student, int> studentRepository, IStudentRepository studentRepository2 )
{
_studentRepository = studentRepository;
_studentRepository2 = studentRepository2;
}
public async Task<IActionResult> Index()
{
//_studentRepository2换成_studentRepository也成，只是没有Login方法
Models.Student student = await _studentRepository2.GetAll().FirstOrDefaultAsync();
int count = await _studentRepository2.CountAsync();
bool b = _studentRepository2.Login("niunan","123456");
string str = $"取出一个学生：{student.Name}，学生总数：{count}, 执行login方法结果：{false}";
return Content($"<meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\" /><div>原文：{src}</div><div>加密后：{jiami}</div><div>解密后：{jiemi}</div><div>{str}</div>","text/html");
}
标签：predicate,Task,return,TEntity,entity,改类,EFCORE,NET7,public From： https://www.cnblogs.com/niunan/p/17586173.html