Entity Framework Core 数据库访问与仓储模式
创建实体模型与数据库
创建实体模型
public class Article
{
public int Id { get; set; }
public string Submitter { get; set; }
public string Title { get; set; }
public string Category { get; set; }
public string Content { get; set; }
public int Traffic { get; set; }
public int CommentNum { get; set; }
public DateTime UpdateTime { get; set; }
public DateTime CreateTime { get; set; }
public string Remark { get; set; }
public bool? IsDeleted { get; set; }
}
设计仓储基类接口
public interface IBaseRepository<TEntity> where TEntity : class
{
Task<TEntity> InsertAsync(TEntity entity,bool autoSave=false,CancellationToken cancellationToken=default);
Task InsertManyAsync(IEnumerable<TEntity> entities, bool autoSave = false, CancellationToken cancellationToken = default);
Task<TEntity> UpdateAsync(TEntity entity, bool autoSave = false, CancellationToken cancellationToken = default);
Task UpdateManyAsync(IEnumerable<TEntity> entities, bool autoSave = false, CancellationToken cancellationToken = default);
Task DeleteAsync(TEntity entity, bool autoSave = false, CancellationToken cancellationToken = default);
Task DeleteAsync(Expression<Func<TEntity, bool>> predicate, bool autoSave = false, CancellationToken cancellationToken = default);
Task DeleteManyAsync(IEnumerable<TEntity> entities, bool autoSave = false, CancellationToken cancellationToken = default);
Task<TEntity> FindAsync(Expression<Func<TEntity, bool>> predicate, bool autoSave = false, CancellationToken cancellationToken = default);
Task<TEntity> GetAsync(Expression<Func<TEntity, bool>> predicate, bool autoSave = false, CancellationToken cancellationToken = default);
Task<List<TEntity>> GetListAsync(CancellationToken cancellationToken = default);
Task<List<TEntity>> GetListAsync(Expression<Func<TEntity, bool>> predicate, bool autoSave = false, CancellationToken cancellationToken = default);
Task<List<TEntity>> GetPageListAsync(int skipCount, int maxResultCount, string sorting, CancellationToken cancellationToken = default);
Task<long> GetCountAsync(CancellationToken cancellationToken = default);
Task<long> GetCountAsync(Expression<Func<TEntity, bool>> predicate, CancellationToken cancellationToken);
}
对仓储基接口进行实现
public class BaseRepository<TEntity> : IBaseRepository<TEntity> where TEntity : class, new()
{
private SwiftCodeBBSContext _context;
public BaseRepository()
{
_context = new SwiftCodeBBSContext();
}
protected SwiftCodeBBSContext DbContext()
{
return _context;
}
public async Task DeleteAsync(TEntity entity, bool autoSave = false, CancellationToken cancellationToken = default)
{
_context.Set<TEntity>().Remove(entity);
if (autoSave)
{
await _context.SaveChangesAsync(cancellationToken);
}
}
public async Task DeleteAsync(Expression<Func<TEntity, bool>> predicate, bool autoSave = false, CancellationToken cancellationToken = default)
{
var dbSet = _context.Set<TEntity>();
var entities = await dbSet.Where(predicate).ToListAsync(cancellationToken);
await DeleteManyAsync(entities, autoSave, cancellationToken);
if (autoSave)
{
await _context.SaveChangesAsync(cancellationToken);
}
}
public async Task DeleteManyAsync(IEnumerable<TEntity> entities, bool autoSave = false, CancellationToken cancellationToken = default)
{
_context.RemoveRange(entities);
if (autoSave)
{
await _context.SaveChangesAsync(cancellationToken);
}
}
public Task<TEntity> FindAsync(Expression<Func<TEntity, bool>> predicate, bool autoSave = false, CancellationToken cancellationToken = default)
{
return _context.Set<TEntity>().Where(predicate).SingleOrDefaultAsync(cancellationToken);
}
public async Task<TEntity> GetAsync(Expression<Func<TEntity, bool>> predicate, bool autoSave = false, CancellationToken cancellationToken = default)
{
var entity = await FindAsync(predicate, autoSave, cancellationToken);
if (entity == null)
{
throw new Exception(nameof(TEntity) + ":数据不存在");
}
return entity;
}
public Task<long> GetCountAsync(CancellationToken cancellationToken = default)
{
return _context.Set<TEntity>().LongCountAsync(cancellationToken);
}
public Task<long> GetCountAsync(Expression<Func<TEntity, bool>> predicate, CancellationToken cancellationToken)
{
return _context.Set<TEntity>().Where(predicate).LongCountAsync(cancellationToken);
}
public Task<List<TEntity>> GetListAsync(CancellationToken cancellationToken = default)
{
return _context.Set<TEntity>().ToListAsync(cancellationToken);
}
public Task<List<TEntity>> GetListAsync(Expression<Func<TEntity, bool>> predicate, bool autoSave = false, CancellationToken cancellationToken = default)
{
return _context.Set<TEntity>().Where(predicate).ToListAsync(cancellationToken);
}
public Task<List<TEntity>> GetPageListAsync(int skipCount, int maxResultCount, string sorting, CancellationToken cancellationToken = default)
{
return _context.Set<TEntity>().Skip(skipCount).Take(maxResultCount).ToListAsync(cancellationToken);
}
public async Task<TEntity> InsertAsync(TEntity entity, bool autoSave = false, CancellationToken cancellationToken = default)
{
var savedEntity = (await _context.Set<TEntity>().AddAsync(entity, cancellationToken)).Entity;
if (autoSave)
{
await _context.SaveChangesAsync(cancellationToken);
}
return savedEntity;
}
public async Task InsertManyAsync(IEnumerable<TEntity> entities, bool autoSave = false, CancellationToken cancellationToken = default)
{
var entityArray = entities.ToArray();
await _context.Set<TEntity>().AddRangeAsync(entityArray, cancellationToken);
if (autoSave)
{
await _context.SaveChangesAsync(cancellationToken);
}
}
public async Task<TEntity> UpdateAsync(TEntity entity, bool autoSave = false, CancellationToken cancellationToken = default)
{
_context.Attach(entity);
var updatedEntity = _context.Update(entity).Entity;
if (autoSave)
{
await _context.SaveChangesAsync(cancellationToken);
}
return updatedEntity;
}
public async Task UpdateManyAsync(IEnumerable<TEntity> entities, bool autoSave = false, CancellationToken cancellationToken = default)
{
_context.Set<TEntity>().UpdateRange(entities);
if (autoSave)
{
await _context.SaveChangesAsync(cancellationToken);
}
}
}
创建数据库
在API层通过Nuget引入Microsoft.EntityFrameworkCore.Design
在Repositories层通过Nuget引入Microsoft.EntityFrameworkCore，Microsoft.EntityFrameworkCore.SqlServer,Microsoft.EntityFrameworkCore.Tools
public class BBSContext : DbContext
{
public BBSContext()
{
}
public BBSContext(DbContextOptions<BBSContext> options) : base(options)
{
}
public DbSet<Article> Articles { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Article>().Property(p => p.Title).HasMaxLength(128);
modelBuilder.Entity<Article>().Property(p => p.Submitter).HasMaxLength(64);
modelBuilder.Entity<Article>().Property(p => p.Category).HasMaxLength(256);
modelBuilder.Entity<Article>().Property(p => p.Content).HasMaxLength(128);
modelBuilder.Entity<Article>().Property(p => p.Remark).HasMaxLength(1024);
}
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
optionsBuilder.UseSqlServer(@"Server=.;Database=CodeBBS; Uid=sa; password=sa;Trusted_Connection=True;Connection Timeout=600;MultipleActiveResultSets=True").LogTo(Console.WriteLine, Microsoft.Extensions.Logging.LogLevel.Information);
}
}
设计应用服务层基类与基接口
public interface IBaseService<TEntity> where TEntity : class
{
Task<TEntity> InsertAsync(TEntity entity, bool autoSave = false, CancellationToken cancellationToken = default);
Task InsertManyAsync(IEnumerable<TEntity> entities, bool autoSave = false, CancellationToken cancellationToken = default);
Task<TEntity> UpdateAsync(TEntity entity, bool autoSave = false, CancellationToken cancellationToken = default);
Task UpdateManyAsync(IEnumerable<TEntity> entities, bool autoSave = false, CancellationToken cancellationToken = default);
Task DeleteAsync(TEntity entity, bool autoSave = false, CancellationToken cancellationToken = default);
Task DeleteAsync(Expression<Func<TEntity, bool>> predicate, bool autoSave = false, CancellationToken cancellationToken = default);
Task DeleteManyAsync(IEnumerable<TEntity> entities, bool autoSave = false, CancellationToken cancellationToken = default);
Task<TEntity> FindAsync(Expression<Func<TEntity, bool>> predicate, bool autoSave = false, CancellationToken cancellationToken = default);
Task<TEntity> GetAsync(Expression<Func<TEntity, bool>> predicate, bool autoSave = false, CancellationToken cancellationToken = default);
Task<List<TEntity>> GetListAsync(CancellationToken cancellationToken = default);
Task<List<TEntity>> GetListAsync(Expression<Func<TEntity, bool>> predicate, bool autoSave = false, CancellationToken cancellationToken = default);
Task<List<TEntity>> GetPageListAsync(int skipCount, int maxResultCount, string sorting, CancellationToken cancellationToken = default);
Task<long> GetCountAsync(CancellationToken cancellationToken = default);
Task<long> GetCountAsync(Expression<Func<TEntity, bool>> predicate, CancellationToken cancellationToken);
}
public class BaseService<TEntity> : IBaseService<TEntity> where TEntity : class, new()
{
public IBaseRepository<TEntity> _baseRepository;
public BaseService(IBaseRepository<TEntity> baseRepository)
{
_baseRepository = baseRepository;
}
public async Task DeleteAsync(TEntity entity, bool autoSave = false, CancellationToken cancellationToken = default)
{
await _baseRepository.DeleteAsync(entity, autoSave, cancellationToken);
}
public async Task DeleteAsync(Expression<Func<TEntity, bool>> predicate, bool autoSave = false, CancellationToken cancellationToken = default)
{
await _baseRepository.DeleteAsync(predicate, autoSave, cancellationToken);
}
public async Task DeleteManyAsync(IEnumerable<TEntity> entities, bool autoSave = false, CancellationToken cancellationToken = default)
{
await _baseRepository.DeleteManyAsync(entities, autoSave, cancellationToken);
}
public Task<TEntity> FindAsync(Expression<Func<TEntity, bool>> predicate, bool autoSave = false, CancellationToken cancellationToken = default)
{
return _baseRepository.FindAsync(predicate, autoSave, cancellationToken);
}
public Task<TEntity> GetAsync(Expression<Func<TEntity, bool>> predicate, bool autoSave = false, CancellationToken cancellationToken = default)
{
return _baseRepository.GetAsync(predicate, autoSave, cancellationToken);
}
public Task<long> GetCountAsync(CancellationToken cancellationToken = default)
{
return _baseRepository.GetCountAsync(cancellationToken);
}
public Task<long> GetCountAsync(Expression<Func<TEntity, bool>> predicate, CancellationToken cancellationToken)
{
return _baseRepository.GetCountAsync(predicate, cancellationToken);
}
public Task<List<TEntity>> GetListAsync(CancellationToken cancellationToken = default)
{
return _baseRepository.GetListAsync(cancellationToken);
}
public Task<List<TEntity>> GetListAsync(Expression<Func<TEntity, bool>> predicate, bool autoSave = false, CancellationToken cancellationToken = default)
{
return _baseRepository.GetListAsync(predicate, autoSave, cancellationToken);
}
public Task<List<TEntity>> GetPageListAsync(int skipCount, int maxResultCount, string sorting, CancellationToken cancellationToken = default)
{
return _baseRepository.GetPageListAsync(skipCount, maxResultCount, sorting, cancellationToken);
}
public Task<TEntity> InsertAsync(TEntity entity, bool autoSave = false, CancellationToken cancellationToken = default)
{
return _baseRepository.InsertAsync(entity, autoSave, cancellationToken);
}
public Task InsertManyAsync(IEnumerable<TEntity> entities, bool autoSave = false, CancellationToken cancellationToken = default)
{
return _baseRepository.InsertManyAsync(entities, autoSave, cancellationToken);
}
public Task<TEntity> UpdateAsync(TEntity entity, bool autoSave = false, CancellationToken cancellationToken = default)
{
return _baseRepository.UpdateAsync(entity, autoSave, cancellationToken);
}
public async Task UpdateManyAsync(IEnumerable<TEntity> entities, bool autoSave = false, CancellationToken cancellationToken = default)
{
await _baseRepository.UpdateManyAsync(entities, autoSave, cancellationToken).ConfigureAwait(false);
}
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