• 【手撸一个ORM】第十步、数据操作工具类 MyDb


    说明

    其实就是数据库操作的一些封装,很久不用SqlCommand操作数据库了,看了点园子里的文章就直接上手写了,功能上没问题,但写法上是否完美高效无法保证,建议有需要的朋友自己重写,当然如果能把最佳实践方式告知一下,不胜感激!!


    因为文件比较大,所以将此类分成了四部分。

    MyDb主体

    using MyOrm.Commons;
    using MyOrm.DbParameters;
    using MyOrm.Expressions;
    using MyOrm.Queryable;
    using MyOrm.Reflections;
    using System;
    using System.Collections.Generic;
    using System.Data.SqlClient;
    using System.Linq.Expressions;
    
    namespace MyOrm
    {
        public partial class MyDb
        {
            private readonly string _connectionString;
    
            private readonly string _prefix;
    
            public MyDb(string connectionString, string prefix = "@")
            {
                _connectionString = connectionString;
                _prefix = prefix;
            }
    
            public MyDb()
            {
                if (string.IsNullOrWhiteSpace(MyDbConfiguration.GetConnectionString()))
                {
                    throw new Exception("MyOrm尚未初始化");
                }
    
                _connectionString = MyDbConfiguration.GetConnectionString();
                _prefix = MyDbConfiguration.GetPrefix();
            }
    
            /// <summary>
            /// 使用默认配置,返回新MyDb实例
            /// </summary>
            /// <returns></returns>
            public static MyDb New()
            {
                return new MyDb();
            }
    
            /// <summary>
            /// 返回新MyDb实例
            /// </summary>
            /// <param name="connectionString"></param>
            /// <param name="prefix"></param>
            /// <returns></returns>
            public static MyDb New(string connectionString, string prefix = "@")
            {
                return new MyDb(connectionString, prefix);
            }
    
            #region 查询
            /// <summary>
            /// 返回MyQueryable实例
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <returns>实体,若记录为空,返回default(T)</returns>
            public MyQueryable<T> Query<T>() where T : class, IEntity, new()
            {
                return new MyQueryable<T>(_connectionString);
            }
    
            /// <summary>
            /// 根据ID加载一个实体
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="id">实体ID</param>
            /// <returns>实体,若记录为空,返回default(T)</returns>
            public T Load<T>(int id) where T : class, IEntity, new()
            {
                return new MyQueryable<T>(_connectionString).Where(t => t.Id == id).FirstOrDefault();
            }
    
            /// <summary>
            /// 根据条件加载一个实体
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="where">查询条件</param>
            /// <param name="orderBy">排序字段</param>
            /// <param name="dbSort">正序或倒序</param>
            /// <returns>实体,若记录为空,返回default(T)</returns>
            public T Load<T>(Expression<Func<T, bool>> where = null,
                             Expression<Func<T, object>> orderBy = null,
                             MyDbOrderBy dbSort = MyDbOrderBy.Asc) where T : class, new()
            {
                var query = new MyQueryable<T>(_connectionString);
                if (where != null)
                {
                    query.Where(where);
                }
    
                if (orderBy != null)
                {
                    query.OrderBy(orderBy, dbSort);
                }
    
                return query.FirstOrDefault();
            }
    
            /// <summary>
            /// 根据条件加载所有实体
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="where">查询条件</param>
            /// <param name="orderBy">排序字段</param>
            /// <param name="dbSort">正序或倒序</param>
            /// <returns>实体列表</returns>
            public List<T> Fetch<T>(Expression<Func<T, bool>> where = null, Expression<Func<T, object>> orderBy = null,
                                    MyDbOrderBy dbSort = MyDbOrderBy.Asc) where T : class, new()
            {
                var query = new MyQueryable<T>(_connectionString);
                if (where != null)
                {
                    query.Where(where);
                }
    
                if (orderBy != null)
                {
                    query.OrderBy(orderBy, dbSort);
                }
    
                return query.ToList();
            }
    
            /// <summary>
            /// 加载分页列表
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="pageIndex">当前页码</param>
            /// <param name="pageSize">每页条数</param>
            /// <param name="recordCount">记录总数</param>
            /// <param name="where">查询条件</param>
            /// <param name="orderBy">排序字段</param>
            /// <param name="dbSort">正序或倒序</param>
            /// <returns>实体列表,输出记录总数</returns>
            public List<T> PageList<T>(int pageIndex,
                int pageSize,
                out int recordCount,
                Expression<Func<T, bool>> where = null,
                Expression<Func<T, object>> orderBy = null,
                MyDbOrderBy dbSort = MyDbOrderBy.Asc) where T : class, new()
            {
                var query = new MyQueryable<T>(_connectionString);
                if (where != null)
                {
                    query.Where(where);
                }
    
                if (orderBy != null)
                {
                    query.OrderBy(orderBy, dbSort);
                }
    
                return query.ToPageList(pageIndex, pageSize, out recordCount);
            }
            #endregion
    
            #region 获取数量
    
            public int GetCount<T>(Expression<Func<T, bool>> expression = null) where T : class, IEntity, new()
            {
                var entityInfo = MyEntityContainer.Get(typeof(T));
    
                if (expression == null)
                {
                    var sql = $"SELECT COUNT(0) FROM [{entityInfo.TableName}]";
                    using (var conn = new SqlConnection(_connectionString))
                    {
                        conn.Open();
                        var command = new SqlCommand(sql, conn);
                        return (int)command.ExecuteScalar();
                    }
                }
                else
                {
                    var resolver = new EditConditionResolver<T>(entityInfo);
                    var result = resolver.Resolve(expression.Body);
                    var condition = result.Condition;
                    var parameters = result.Parameters;
    
                    condition = string.IsNullOrWhiteSpace(condition) ? "1=1" : condition;
    
                    var sql = $"SELECT COUNT(0) FROM [{entityInfo.TableName}] WHERE [{condition}]";
                    using (var conn = new SqlConnection(_connectionString))
                    {
                        conn.Open();
                        var command = new SqlCommand(sql, conn);
                        command.Parameters.AddRange(parameters.Parameters);
                        return (int)command.ExecuteScalar();
                    }
                }
            }
            #endregion
    
            #region 执行SQL语句
            //public List<T> Fetch<T>(string sql, MyDbParameters parameters = null)
            //{
    
            //}
            #endregion
        }
    }

    MyDbUpdate 更新的相关操作

    using MyOrm.Commons;
    using MyOrm.DbParameters;
    using MyOrm.Expressions;
    using MyOrm.Reflections;
    using MyOrm.SqlBuilder;
    using System;
    using System.Collections.Generic;
    using System.Data.SqlClient;
    using System.Linq;
    using System.Linq.Expressions;
    
    namespace MyOrm
    {
        public partial class MyDb
        {
            /// <summary>
            /// 更新一个实体
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="entity">要更新的实体</param>
            /// <returns>受影响的记录数</returns>
            public int Update<T>(T entity) where T : class, IEntity, new()
            {
                var entityInfo = MyEntityContainer.Get(typeof(T));
    
                var sqlBuilder = new SqlServerBuilder();
                var sql = sqlBuilder.Update(entityInfo, "");
    
                var parameters = new MyDbParameters();
                parameters.Add(entity);
    
                var command = new SqlCommand(sql);
                command.Parameters.AddRange(parameters.Parameters);
    
                using (var conn = new SqlConnection(_connectionString))
                {
                    conn.Open();
                    command.Connection = conn;
                    return command.ExecuteNonQuery();
                }
            }
    
            /// <summary>
            /// 更新多个实体
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="entityList">要更新的实体列表</param>
            /// <returns>受影响的记录数</returns>
            public int Update<T>(List<T> entityList) where T : class, IEntity, new()
            {
                var entityInfo = MyEntityContainer.Get(typeof(T));
    
                var sqlBuilder = new SqlServerBuilder();
                var sql = sqlBuilder.Update(entityInfo, "");
    
                var count = 0;
    
                using (var conn = new SqlConnection(_connectionString))
                {
                    conn.Open();
                    using (var trans = conn.BeginTransaction())
                    {
                        try
                        {
                            foreach (var entity in entityList)
                            {
                                using (var command = new SqlCommand(sql, conn, trans))
                                {
                                    var param = new MyDbParameters();
                                    param.Add(entity);
                                    command.Parameters.AddRange(param.Parameters);
                                    count += command.ExecuteNonQuery();
                                }
                            }
                            trans.Commit();
                        }
                        catch (Exception)
                        {
                            trans.Rollback();
                            count = 0;
                        }
                    }
                }
    
                return count;
            }
    
            /// <summary>
            /// 如果不存在,则更新
            /// 如:UpdateIfNotExists(user, u=>u.Name == user.Name && u.Id != user.Id)
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="entity"></param>
            /// <param name="where"></param>
            /// <returns>受影响的记录数</returns>
            public int UpdateIfNotExits<T>(T entity, Expression<Func<T, bool>> where)
            {
                var entityInfo = MyEntityContainer.Get(typeof(T));
    
                var resolver = new EditConditionResolver<T>(entityInfo);
                var result = resolver.Resolve(where.Body);
                var condition = result.Condition;
                var parameters = result.Parameters;
                parameters.Add(entity);
    
                condition = string.IsNullOrWhiteSpace(condition) ? "1=1" : condition;
    
                var sqlBuilder = new SqlServerBuilder();
                var sql = sqlBuilder.Update(entityInfo, "");
                sql += $" AND NOT EXISTS (SELECT 1 FROM [{entityInfo.TableName}] WHERE {condition})";
    
                var command = new SqlCommand(sql);
                command.Parameters.AddRange(parameters.Parameters);
    
                using (var conn = new SqlConnection(_connectionString))
                {
                    conn.Open();
                    command.Connection = conn;
                    return command.ExecuteNonQuery();
                }
            }
    
            #region 扩展
            /// <summary>
            /// 通过Id修改指定列
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="id">实体ID</param>
            /// <param name="kvs">属性和值的键值对。用法 DbKvs.New().Add("属性名", 值)</param>
            /// <returns>受影响的记录数</returns>
            public int Update<T>(int id, DbKvs kvs)
            {
                var entityInfo = MyEntityContainer.Get(typeof(T));
                var setProperties = kvs.Where(kv => kv.Key != "Id").Select(kv => kv.Key);
                var includeProperties = entityInfo.Properties.Where(p => setProperties.Contains(p.Name)).ToList();
                if (includeProperties.Count == 0)
                {
                    return 0;
                }
    
                var sql =
                    $"UPDATE [{entityInfo.TableName}] SET {string.Join(",", includeProperties.Select(p => $"{p.FieldName}=@{p.Name}"))} WHERE Id=@Id";
                var parameters = kvs.ToSqlParameters();
                parameters.Add(new SqlParameter("@Id", id));
                using (var conn = new SqlConnection(_connectionString))
                {
                    conn.Open();
                    var command = new SqlCommand(sql, conn);
                    command.Parameters.AddRange(parameters.ToArray());
                    return command.ExecuteNonQuery();
                }
            }
    
            /// <summary>
            /// 通过查询条件修改指定列
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="kvs">属性和值的键值对。用法 DbKvs.New().Add("属性名", 值)</param>
            /// <param name="expression">查询条件,注意:不支持导航属性,如 "student => student.School.Id > 0" 将无法解析</param>
            /// <returns>受影响的记录数</returns>
            public int Update<T>(Expression<Func<T, bool>> expression, DbKvs kvs)
            {
                var entityInfo = MyEntityContainer.Get(typeof(T));
                var setProperties = kvs.Where(kv => kv.Key != "Id").Select(kv => kv.Key);
                var includeProperties = entityInfo.Properties.Where(p => setProperties.Contains(p.Name)).ToList();
                if (includeProperties.Count == 0)
                {
                    return 0;
                }
    
                string sql;
                List<SqlParameter> parameters;
                if (expression == null)
                {
                    sql =
                        $"UPDATE [{entityInfo.TableName}] SET {string.Join(",", includeProperties.Select(p => $"{p.FieldName}=@{p.Name}"))} WHERE Id=@Id";
                    parameters = kvs.ToSqlParameters();
                }
                else
                {
                    var resolver = new EditConditionResolver<T>(entityInfo);
                    var result = resolver.Resolve(expression.Body);
                    var where = result.Condition;
                    var whereParameters = result.Parameters;
    
                    parameters = kvs.ToSqlParameters();
                    parameters.AddRange(whereParameters.Parameters);
    
                    where = string.IsNullOrWhiteSpace(where) ? "1=1" : where;
    
                    sql =
                        $"UPDATE [{entityInfo.TableName}] SET {string.Join(",", includeProperties.Select(p => $"{p.FieldName}=@{p.Name}"))} WHERE {where}";
                }
    
                using (var conn = new SqlConnection(_connectionString))
                {
                    conn.Open();
                    var command = new SqlCommand(sql, conn);
                    command.Parameters.AddRange(parameters.ToArray());
                    return command.ExecuteNonQuery();
                }
            }
    
            /// <summary>
            /// 修改实体的指定属性
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="entity">要修改的实体</param>
            /// <param name="includes">要修改的属性名称,注意:是实体的属性名而不是数据库字段名</param>
            /// <param name="ignoreAttribute">是否忽略实体的UpdateIgnore描述。默认为true,既includes中包含的所有属性都会被修改</param>
            /// <returns>受影响的记录数</returns>
            public int UpdateInclude<T>(T entity, IEnumerable<string> includes, bool ignoreAttribute = true) where T : IEntity
            {
                var entityInfo = MyEntityContainer.Get(typeof(T));
                var includeProperties = entityInfo.Properties.Where(p => includes.Contains(p.Name) && p.Name != "Id").ToList();
    
                if (!ignoreAttribute)
                {
                    includeProperties = includeProperties.Where(p => !p.UpdateIgnore).ToList();
                }
    
                if (includeProperties.Count == 0)
                {
                    return 0;
                }
    
                var sql =
                    $"UPDATE [{entityInfo.TableName}] SET {string.Join(",", includeProperties.Select(p => $"{p.FieldName}=@{p.Name}"))} WHERE Id=@Id";
                var parameters = new List<SqlParameter> { new SqlParameter("@Id", entity.Id) };
    
                foreach (var property in includeProperties)
                {
                    parameters.Add(new SqlParameter($"@{property.Name}", ResolveParameterValue(property.PropertyInfo.GetValue(entity))));
                }
    
                using (var conn = new SqlConnection(_connectionString))
                {
                    conn.Open();
                    var command = new SqlCommand(sql, conn);
                    command.Parameters.AddRange(parameters.ToArray());
                    return command.ExecuteNonQuery();
                }
            }
    
            /// <summary>
            /// 修改实体的指定属性
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="entity">要修改的实体</param>
            /// <param name="expression">要修改的属性,注意不支持导航属性及其子属性</param>
            /// <param name="ignoreAttribute">是否忽略实体的UpdateIgnore描述。默认为true,既includes中包含的所有属性都会被修改</param>
            /// <returns>受影响的记录数</returns>
            public int UpdateInclude<T>(T entity, Expression<Func<T, object>> expression, bool ignoreAttribute = true) where T : IEntity
            {
                var entityInfo = MyEntityContainer.Get(typeof(T));
                var visitor = new ObjectMemberVisitor();
                visitor.Visit(expression);
                var include = visitor.GetPropertyList();
                return UpdateInclude(entity, include, ignoreAttribute);
            }
    
            /// <summary>
            /// 修改实体除指定属性外的其他属性
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="entity">要修改的实体</param>
            /// <param name="ignore">要忽略的属性,注意:是实体的属性名而不是数据表的列名</param>
            /// <param name="ignoreAttribute">是否忽略实体的UpdateIgnore描述。默认为true,既includes中包含的所有属性都会被修改</param>
            /// <returns>受影响的记录数</returns>
            public int UpdateIgnore<T>(T entity, IEnumerable<string> ignore, bool ignoreAttribute = true) where T : IEntity
            {
                var entityInfo = MyEntityContainer.Get(typeof(T));
                var includeProperties = entityInfo.Properties.Where(p => !ignore.Contains(p.Name) && p.Name != "Id").ToList();
    
                if (!ignoreAttribute)
                {
                    includeProperties = includeProperties.Where(p => !p.UpdateIgnore).ToList();
                }
    
                if (includeProperties.Count() == 0)
                {
                    return 0;
                }
    
                var sql =
                    $"UPDATE [{entityInfo.TableName}] SET {string.Join(",", includeProperties.Select(p => $"{p.FieldName}=@{p.Name}"))} WHERE Id=@Id";
                var parameters = new List<SqlParameter> { new SqlParameter("@Id", entity.Id) };
    
                foreach (var property in includeProperties)
                {
                    parameters.Add(new SqlParameter($"@{property.Name}", ResolveParameterValue(property.PropertyInfo.GetValue(entity))));
                }
    
                using (var conn = new SqlConnection(_connectionString))
                {
                    conn.Open();
                    var command = new SqlCommand(sql, conn);
                    command.Parameters.AddRange(parameters.ToArray());
                    return command.ExecuteNonQuery();
                }
            }
    
            /// <summary>
            /// 
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="entity">要修改的实体</param>
            /// <param name="expression">要修改的属性,注意不支持导航属性及其子属性</param>
            /// <param name="ignoreAttribute">是否忽略实体的UpdateIgnore描述。默认为true,既includes中包含的所有属性都会被修改</param>
            /// <returns>受影响的记录数</returns>
            public int UpdateIgnore<T>(T entity, Expression<Func<T, object>> expression, bool ignoreAttribute = true) where T : IEntity
            {
                var entityInfo = MyEntityContainer.Get(typeof(T));
                var visitor = new ObjectMemberVisitor();
                visitor.Visit(expression);
                var include = visitor.GetPropertyList();
                return UpdateIgnore(entity, include, ignoreAttribute);
            }
            #endregion
    
            private object ResolveParameterValue(object val)
            {
                if (val is null)
                {
                    val = DBNull.Value;
                }
    
                return val;
            }
        }
    }

    MyDbInsert 插入相关的操作

    using MyOrm.Commons;
    using MyOrm.DbParameters;
    using MyOrm.Expressions;
    using MyOrm.Reflections;
    using MyOrm.SqlBuilder;
    using System;
    using System.Collections.Generic;
    using System.Data.SqlClient;
    using System.Linq;
    using System.Linq.Expressions;
    
    namespace MyOrm
    {
        public partial class MyDb
        {
            /// <summary>
            /// 创建一个实体,新的记录Id将绑定到entity的Id属性
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="entity">要创建的实体</param>
            /// <returns>新生成记录的ID,若失败返回0</returns>
            public int Insert<T>(T entity) where T : class, IEntity, new()
            {
                var entityInfo = MyEntityContainer.Get(typeof(T));
    
                var sqlBuilder = new SqlServerBuilder();
                var sql = sqlBuilder.Insert(entityInfo);
    
                var parameters = new MyDbParameters();
                parameters.Add(entity);
    
                var command = new SqlCommand(sql);
                command.Parameters.AddRange(parameters.Parameters);
    
                using (var conn = new SqlConnection(_connectionString))
                {
                    conn.Open();
                    command.Connection = conn;
                    var result = command.ExecuteScalar().ToString();
                    entity.Id = Convert.ToInt32(string.IsNullOrWhiteSpace(result) ? "0" : result);
                    return entity.Id;
                }
            }
    
            /// <summary>
            /// 如果不满足条件则创建一个实体,
            /// 如限制用户名不能重复 InsertIfNotExist(user, u => u.Name == user.Name)
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="entity">要创建的实体</param>
            /// <param name="where">条件</param>
            /// <returns>新生成记录的ID,若失败返回0</returns>
            public int InsertIfNotExists<T>(T entity, Expression<Func<T, bool>> where) where T : class, IEntity, new()
            {
                if (where == null)
                {
                    return Insert(entity);
                }
                else
                {
                    var entityInfo = MyEntityContainer.Get(typeof(T));
                    var resolver = new EditConditionResolver<T>(entityInfo);
                    var result = resolver.Resolve(where.Body);
                    var condition = result.Condition;
                    var parameters = result.Parameters;
                    parameters.Add(entity);
    
                    condition = string.IsNullOrWhiteSpace(condition) ? "1=1" : condition;
    
                    var sqlBuilder = new SqlServerBuilder();
                    var sql = sqlBuilder.InsertIfNotExists(entityInfo, condition);
                    var command = new SqlCommand(sql);
                    command.Parameters.AddRange(parameters.Parameters);
    
                    using (var conn = new SqlConnection(_connectionString))
                    {
                        conn.Open();
                        command.Connection = conn;
                        var idString = command.ExecuteScalar().ToString();
                        entity.Id = Convert.ToInt32(string.IsNullOrWhiteSpace(idString) ? "0" : idString);
                        return entity.Id;
                    }
                }
            }
    
            /// <summary>
            /// 批量创建实体,注意此方法效率不高
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="entityList">实体列表</param>
            /// <returns>受影响的记录数</returns>
            public int Insert<T>(List<T> entityList) where T : class, IEntity, new()
            {
                var entityInfo = MyEntityContainer.Get(typeof(T));
    
                var sqlBuilder = new SqlServerBuilder();
                var sql = sqlBuilder.Insert(entityInfo);
    
                var count = 0;
    
                using (var conn = new SqlConnection(_connectionString))
                {
                    conn.Open();
                    using (var trans = conn.BeginTransaction())
                    {
                        try
                        {
                            foreach (var entity in entityList)
                            {
                                using (var command = new SqlCommand(sql, conn, trans))
                                {
                                    var parameters = new MyDbParameters();
                                    parameters.Add(entity);
                                    command.Parameters.AddRange(parameters.Parameters);
                                    var result = command.ExecuteScalar().ToString();
                                    entity.Id = Convert.ToInt32(string.IsNullOrWhiteSpace(result) ? "0" : result);
                                    count++;
                                }
                            }
                            trans.Commit();
                        }
                        catch
                        {
                            trans.Rollback();
                            count = 0;
                        }
                    }
                }
    
                return count;
            }
        }
    }

    MyDbDelete 删除相关的操作

    using MyOrm.Commons;
    using MyOrm.Expressions;
    using MyOrm.Reflections;
    using System;
    using System.Collections.Generic;
    using System.Data.SqlClient;
    using System.Linq.Expressions;
    
    namespace MyOrm
    {
        public partial class MyDb
        {
            #region 删除
    
            /// <summary>
            /// 根据ID删除记录,如果支持软删除并且非强制删除,则更新IsDel字段为true,否则,删除记录
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="id">要删除的实体ID</param>
            /// <param name="isForce">是否强制删除,默认为false</param>
            /// <returns>受影响的记录数</returns>
            public int Delete<T>(int id, bool isForce = false) where T : class, IEntity, new()
            {
                var entityInfo = MyEntityContainer.Get(typeof(T));
                if (isForce || !entityInfo.IsSoftDelete)
                {
                    var sql = $"DELETE [{entityInfo.TableName}] WHERE [{entityInfo.KeyColumn}]={_prefix}Id";
                    using (var conn = new SqlConnection(_connectionString))
                    {
                        conn.Open();
                        var command = new SqlCommand(sql, conn);
                        command.Parameters.AddWithValue($"{_prefix}Id", id);
                        return command.ExecuteNonQuery();
                    }
                }
                else
                {
                    var sql = $"UPDATE [{entityInfo.TableName}] SET IsDel=1 WHERE [{entityInfo.KeyColumn}]={_prefix}Id";
                    using (var conn = new SqlConnection(_connectionString))
                    {
                        conn.Open();
                        var command = new SqlCommand(sql, conn);
                        command.Parameters.AddWithValue($"{_prefix}Id", id);
                        return command.ExecuteNonQuery();
                    }
                }
            }
    
            /// <summary>
            /// 根据ID批量删除记录,如果支持软删除并且非强制删除,则更新IsDel字段为true,否则,删除记录
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="idList">要删除的ID列表</param>
            /// <param name="isForce">是否强制删除,默认为false</param>
            /// <returns>受影响的记录数</returns>
            public int Delete<T>(IEnumerable<int> idList, bool isForce = false) where T : class, IEntity, new()
            {
                var entityInfo = MyEntityContainer.Get(typeof(T));
                if (isForce || !entityInfo.IsSoftDelete)
                {
                    var sql =
                        $"EXEC('DELETE [{entityInfo.TableName}] WHERE [{entityInfo.KeyColumn}] in ('+{_prefix}Ids+')')";
                    using (var conn = new SqlConnection(_connectionString))
                    {
                        conn.Open();
                        var command = new SqlCommand(sql, conn);
                        command.Parameters.AddWithValue($"{_prefix}Ids", string.Join(",", idList));
                        return command.ExecuteNonQuery();
                    }
                }
                else
                {
                    var sql = $"EXEC('UPDATE [{entityInfo.TableName}] SET IsDel=1 WHERE [{entityInfo.KeyColumn}] in ('+{_prefix}Ids+')')";
                    using (var conn = new SqlConnection(_connectionString))
                    {
                        conn.Open();
                        var command = new SqlCommand(sql, conn);
                        command.Parameters.AddWithValue($"{_prefix}Id", idList);
                        return command.ExecuteNonQuery();
                    }
                }
            }
    
            /// <summary>
            /// 根据条件删除记录,如果支持软删除并且非强制删除,则更新IsDel字段为true,否则,删除记录
            /// </summary>
            /// <typeparam name="T"></typeparam>
            /// <param name="expression">条件,注意不支持导航属性及其子属性</param>
            /// <param name="isForce">是否强制删除</param>
            /// <returns>受影响的记录数</returns>
            public int Delete<T>(Expression<Func<T, bool>> expression, bool isForce) where T : IEntity
            {
                var entityInfo = MyEntityContainer.Get(typeof(T));
    
                var resolver = new EditConditionResolver<T>(entityInfo);
                var result = resolver.Resolve(expression.Body);
                var condition = result.Condition;
                var parameters = result.Parameters;
    
                condition = string.IsNullOrWhiteSpace(condition) ? "1=1" : condition;
                string sql;
                if (isForce || !entityInfo.IsSoftDelete)
                {
                    sql =
                        $"DELETE [{entityInfo.TableName}] WHERE {condition}";
                }
                else
                {
                    sql =
                        $"UPDATE [{entityInfo.TableName}] SET IsDel=1 WHERE {condition}";
                }
    
                using (var conn = new SqlConnection(_connectionString))
                {
                    conn.Open();
                    var command = new SqlCommand(sql, conn);
                    command.Parameters.AddRange(parameters.Parameters);
                    return command.ExecuteNonQuery();
                }
            }
            #endregion
        }
    }
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  • 原文地址:https://www.cnblogs.com/diwu0510/p/10663464.html
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