在日常操作中，我们经常会对一些数据进行批量更新，
我在使用EF的时候，没有找到比较好的批量更新的解决方案，
便参考了张占岭前辈的博客，整合了这么一个简略版的使用实体类生成数据库增删改SQL的操作类
在进行更新和删除的时候，会针对的主键进行更新或者删除，所以我们需要给实体类用于主键的字段进行一个特性的标识
下面贴上代码，有不足或者错误之处希望大家多多指正
/// <summary> /// 根据实体来生成批量新增、修改、删除的Sql语句 /// 在Update和Delete /// </summary> /// <typeparam name="TEntity">实体</typeparam> public class EntityToSQL<TEntity> where TEntity : class { #region 根据集合获取SQL语句 /// <summary> /// 执行SQL，根据SQL操作的类型 /// </summary> /// <typeparam name="TEntity"></typeparam> /// <param name="list"></param> /// <param name="sqlType"></param> /// <returns></returns> /// </summary> /// <param name="list"></param> /// <param name="sqlType"></param> /// <returns></returns> public static string GetSql(IEnumerable<TEntity> list, SqlType sqlType) { return GetSql(list, sqlType, null); } /// <summary> /// 执行SQL，根据SQL操作的类型 /// </summary> /// <typeparam name="TEntity"></typeparam> /// <param name="list"></param> /// <param name="sqlType"></param> /// <returns></returns> public static string GetSql(IEnumerable<TEntity> list, SqlType sqlType, params string[] fieldParams) { var sqlstr = new StringBuilder(); switch (sqlType) { case SqlType.Insert: list.ToList().ForEach(i => { Tuple<string, object[]> sql = CreateInsertSql(i); sqlstr.AppendFormat(sql.Item1, sql.Item2); }); break; case SqlType.Update: list.ToList().ForEach(i => { Tuple<string, object[]> sql = CreateUpdateSql(i, fieldParams); sqlstr.AppendFormat(sql.Item1, sql.Item2); }); break; case SqlType.Delete: list.ToList().ForEach(i => { Tuple<string, object[]> sql = CreateDeleteSql(i); sqlstr.AppendFormat(sql.Item1, sql.Item2); }); break; default: throw new ArgumentException("请输入正确的参数"); } return sqlstr.ToString(); } #endregion #region 构建Update语句串 /// <summary> /// 构建Update语句串 /// 注意：如果本方法过滤了int,decimal类型更新为０的列，如果希望更新它们需要指定FieldParams参数 /// </summary> /// <param name="entity">实体列表</param> /// <param name="fieldParams">要更新的字段</param> /// <returns></returns> private static Tuple<string, object[]> CreateUpdateSql(TEntity entity, params string[] fieldParams) { if (entity == null) throw new ArgumentException("数据库实体不能为空"); List<string> pkList = GetPrimaryKeyName(); var entityType = entity.GetType(); var tableFields = new List<PropertyInfo>(); if (fieldParams != null && fieldParams.Count() > 0) { tableFields = entityType.GetProperties().Where(i => fieldParams.Contains(i.Name, StringComparer.OrdinalIgnoreCase)).ToList(); } else { tableFields = entityType.GetProperties().Where(i => !pkList.Contains(i.Name) && i.GetValue(entity, null) != null && !i.PropertyType.IsEnum && !(i.PropertyType == typeof(ValueType) && Convert.ToInt64(i.GetValue(entity, null)) == 0) && !(i.PropertyType == typeof(DateTime) && Convert.ToDateTime(i.GetValue(entity, null)) == DateTime.MinValue) && i.PropertyType != typeof(EntityState) && i.GetCustomAttributes(false).Where(j => j.GetType() == typeof(NavigationAttribute)) != null//过滤导航属性 && (i.PropertyType.IsValueType || i.PropertyType == typeof(string)) ).ToList(); } //过滤主键，航行属性，状态属性等 if (pkList == null || pkList.Count() == 0) throw new ArgumentException("表实体没有主键"); var arguments = new List<object>(); var builder = new StringBuilder(); foreach (var change in tableFields) { if (pkList.Contains(change.Name)) continue; if (arguments.Count != 0) builder.Append(", "); builder.Append(change.Name + " = {" + arguments.Count + "}"); if (change.PropertyType == typeof(string) || change.PropertyType == typeof(DateTime) || change.PropertyType == typeof(DateTime?) || change.PropertyType == typeof(bool?) || change.PropertyType == typeof(bool)) arguments.Add("'" + change.GetValue(entity, null).ToString().Replace("'", "char(39)") + "'"); else arguments.Add(change.GetValue(entity, null)); } if (builder.Length == 0) throw new Exception("没有任何属性进行更新"); builder.Insert(0, " UPDATE " + string.Format("[{0}]", entityType.Name) + " SET "); builder.Append(" WHERE "); bool firstPrimaryKey = true; foreach (var primaryField in pkList) { if (firstPrimaryKey) firstPrimaryKey = false; else builder.Append(" AND "); object val = entityType.GetProperty(primaryField).GetValue(entity, null); Type pkType = entityType.GetProperty(primaryField).GetType(); builder.Append(GetEqualStatment(primaryField, arguments.Count, pkType)); arguments.Add(val); } return new Tuple<string, object[]>(builder.ToString(), arguments.ToArray()); } #endregion #region 构建Insert语句串 /// <summary> /// 构建Insert语句串 /// 主键为自增时，如果主键值为0，我们将主键插入到SQL串中 /// </summary> /// <typeparam name="TEntity"></typeparam> /// <param name="entity"></param> /// <returns></returns> private static Tuple<string, object[]> CreateInsertSql(TEntity entity) { if (entity == null) throw new ArgumentException("数据库实体不能为空"); Type entityType = entity.GetType(); var table = entityType.GetProperties().Where(i => i.PropertyType != typeof(EntityKey) && i.PropertyType != typeof(EntityState) && i.Name != "IsValid" && i.GetValue(entity, null) != null && !i.PropertyType.IsEnum && i.GetCustomAttributes(false).Where(j => j.GetType() == typeof(NavigationAttribute)) != null && (i.PropertyType.IsValueType || i.PropertyType == typeof(string))).ToArray();//过滤主键，航行属性，状态属性等 var pkList = new List<string>(); if (GetPrimaryKey() != null)//有时主键可能没有设计，这对于添加操作是可以的 pkList = GetPrimaryKeyName(); var arguments = new List<object>(); var fieldbuilder = new StringBuilder(); var valuebuilder = new StringBuilder(); fieldbuilder.Append(" INSERT INTO " + string.Format("[{0}]", entityType.Name) + " ("); foreach (var member in table) { if (pkList.Contains(member.Name) && Convert.ToString(member.GetValue(entity, null)) == "0") continue; object value = member.GetValue(entity, null); if (value != null) { if (arguments.Count != 0) { fieldbuilder.Append(", "); valuebuilder.Append(", "); } fieldbuilder.Append(member.Name); if (member.PropertyType == typeof(string) || member.PropertyType == typeof(DateTime) || member.PropertyType == typeof(DateTime?) || member.PropertyType == typeof(Boolean?) || member.PropertyType == typeof(Boolean) ) valuebuilder.Append("'{" + arguments.Count + "}'"); else valuebuilder.Append("{" + arguments.Count + "}"); if (value is string) value = value.ToString().Replace("'", "char(39)"); arguments.Add(value); } } fieldbuilder.Append(") Values ("); fieldbuilder.Append(valuebuilder.ToString()); fieldbuilder.Append(");"); return new Tuple<string, object[]>(fieldbuilder.ToString(), arguments.ToArray()); } #endregion #region 构建Delete语句串 /// <summary> /// 构建Delete语句串 /// </summary> /// <typeparam name="TEntity"></typeparam> /// <param name="entity"></param> /// <returns></returns> private static Tuple<string, object[]> CreateDeleteSql(TEntity entity) { if (entity == null) throw new ArgumentException("数据库实体不能为空"); Type entityType = entity.GetType(); List<string> pkList = GetPrimaryKeyName(); if (pkList == null || pkList.Count == 0) throw new ArgumentException("表实体没有主键"); var arguments = new List<object>(); var builder = new StringBuilder(); builder.Append(" Delete from " + string.Format("[{0}]", entityType.Name)); builder.Append(" WHERE "); bool firstPrimaryKey = true; foreach (var primaryField in pkList) { if (firstPrimaryKey) firstPrimaryKey = false; else builder.Append(" AND "); Type pkType = entityType.GetProperty(primaryField).GetType(); object val = entityType.GetProperty(primaryField).GetValue(entity, null); builder.Append(GetEqualStatment(primaryField, arguments.Count, pkType)); arguments.Add(val); } return new Tuple<string, object[]>(builder.ToString(), arguments.ToArray()); } #endregion #region 准备参数 /// <summary> /// 获取Where条件 /// </summary> /// <param name="fieldName"></param> /// <param name="paramId"></param> /// <param name="pkType"></param> /// <returns></returns> private static string GetEqualStatment(string fieldName, int paramId, Type pkType) { if (pkType.IsValueType) return string.Format("{0} = {1}", fieldName, GetParamTag(paramId)); return string.Format("{0} = '{1}'", fieldName, GetParamTag(paramId)); } private static string GetParamTag(int paramId) { return "{" + paramId + "}"; } /// <summary> /// 获取标识为主键或者导航属性的属性 /// </summary> /// <returns></returns> private static List<PropertyInfo> GetPrimaryKey() { Type entityType = typeof(TEntity); var retu = entityType.GetProperties().Where(x => x.GetCustomAttributes().Where(j => j.GetType() == typeof(NavigationAttribute)).Count() > 0); if (retu != null && retu.Count() > 0) return retu.ToList(); return null; } /// <summary> /// 获取特性的名字 /// </summary> /// <returns></returns> private static List<string> GetPrimaryKeyName() { List<string> resu = new List<string>(); List<PropertyInfo> list = GetPrimaryKey(); if (list != null && list.Count > 0) resu = list.Select(x => x.Name).ToList(); return resu; } #endregion } /// <summary> /// 属性的导航属性（用于标识实体的主键） /// </summary> public class NavigationAttribute : Attribute { } /// <summary> /// SQL操作类型 /// </summary> public enum SqlType { Insert, Update, Delete, }
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