Dapper+Sqlite执行增删改查功能

Posted 2020-10-20 hua896

楼主前段时间无聊买了个阿里云的服务器配置是最低配的 如果装了mysql  内存貌似不够用，于是用了sqlite代替关系型数据库。

首先说下sqlite优缺点

优点

   1. sqlite不用安装，不用配置，不用启动，整个数据库相当于一个文件,直接存放在磁盘上，因此它有很好的迁移性。

   2. sqlite是轻量级数据库，它可以用作关系数据库，不用任何启动任何系统进程。

   3. 它可以运行在Windows,Linux,Mac OSX等系统，同样，它也可以工作在许多嵌入式操作系统下。

缺点

  1.它的性能发挥只能在存放较小的数据量情况下。不能当做MYSQL甚至ORACLE来使用。

  2.在大数据量的情况下表现较差 但是中小站点一般情况下数据量不超过10万。

  3. sqlite 的写入速度很慢（使用Dapper插入1000条数据差不多1-2秒），同时也不适合多线程插入。

适用场景

   个人网站基本上是一个人管理，一般情况下只有一个人在访问后台，没有并发。

   可以在一些设备本身的存储设备或者外接的存储设备中创建用于保存数据的文件。

使用Dapper连接sqlite关系型数据库代码如下：

public class DbBase : IDisposable
    {
        private string paramPrefix = "@";
        private string providerName = "System.Data.SQLite";
        private IDbConnection dbConnecttion;
        private DbProviderFactory dbFactory;
        private DBType _dbType = DBType.SqlServer;
        public IDbConnection DbConnecttion
        {
            get
            {
                return dbConnecttion;
            }
        }
        public IDbTransaction DbTransaction
        {
            get
            {
                return dbConnecttion.BeginTransaction();
            }
        }
        public string ParamPrefix
        {
            get
            {
                return paramPrefix;
            }
        }
        public string ProviderName
        {
            get
            {
                return providerName;
            }
        }
        public DBType DbType
        {
            get
            {
                return _dbType;
            }
        }

        public DbBase(string connectionStringName)
        {
            var connStr = ConfigurationManager.ConnectionStrings[connectionStringName].ConnectionString;
            if (!string.IsNullOrEmpty(ConfigurationManager.ConnectionStrings[connectionStringName].ProviderName))
                providerName = ConfigurationManager.ConnectionStrings[connectionStringName].ProviderName;
            else
                throw new Exception("ConnectionStrings中没有配置提供程序ProviderName！");
            dbFactory = DbProviderFactories.GetFactory(providerName);
            dbConnecttion = dbFactory.CreateConnection();
            dbConnecttion.ConnectionString = connStr;
            dbConnecttion.Open();
            SetParamPrefix();
        }


        private void SetParamPrefix()
        {
            string dbtype = (dbFactory == null ? dbConnecttion.GetType() : dbFactory.GetType()).Name;

            // 使用类型名判断
            if (dbtype.StartsWith("MySql")) _dbType = DBType.MySql;
            else if (dbtype.StartsWith("SqlCe")) _dbType = DBType.SqlServerCE;
            else if (dbtype.StartsWith("Npgsql")) _dbType = DBType.PostgreSQL;
            else if (dbtype.StartsWith("Oracle")) _dbType = DBType.Oracle;
            else if (dbtype.StartsWith("SQLite")) _dbType = DBType.SQLite;
            else if (dbtype.StartsWith("System.Data.SqlClient.")) _dbType = DBType.SqlServer;
            // else try with provider name
            else if (providerName.IndexOf("MySql", StringComparison.InvariantCultureIgnoreCase) >= 0) _dbType = DBType.MySql;
            else if (providerName.IndexOf("SqlServerCe", StringComparison.InvariantCultureIgnoreCase) >= 0) _dbType = DBType.SqlServerCE;
            else if (providerName.IndexOf("Npgsql", StringComparison.InvariantCultureIgnoreCase) >= 0) _dbType = DBType.PostgreSQL;
            else if (providerName.IndexOf("Oracle", StringComparison.InvariantCultureIgnoreCase) >= 0) _dbType = DBType.Oracle;
            else if (providerName.IndexOf("SQLite", StringComparison.InvariantCultureIgnoreCase) >= 0) _dbType = DBType.SQLite;

            if (_dbType == DBType.MySql && dbConnecttion != null && dbConnecttion.ConnectionString != null && dbConnecttion.ConnectionString.IndexOf("Allow User Variables=true") >= 0)
                paramPrefix = "?";
            if (_dbType == DBType.Oracle)
                paramPrefix = ":";
        }

        public void Dispose()
        {
            if (dbConnecttion != null)
            {
                try
                {
                    dbConnecttion.Dispose();
                }
                catch { }
            }
        }
    }
    public enum DBType
    {
        SqlServer,
        SqlServerCE,
        MySql,
        PostgreSQL,
        Oracle,
        SQLite
    }

 /// <summary>
        /// 插入数据
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="dbs"></param>
        /// <param name="t"></param>
        /// <param name="transaction"></param>
        /// <param name="commandTimeout"></param>
        /// <returns></returns>
        public static bool Insert<T>(this DbBase dbs, T t, IDbTransaction transaction = null, int? commandTimeout = null) where T : class
        {
            var db = dbs.DbConnecttion;
            var sql = SqlQuery<T>.Builder(dbs);
            var flag = db.Execute(sql.InsertSql, t, transaction, commandTimeout);
            return flag == 1;
        }

        /// <summary>
        /// 插入数据
        /// </summary>
        /// <typeparam name="T">模型类型</typeparam>
        /// <param name="dbs">理解数据</param>
        /// <param name="t">数据内容</param>
        /// <param name="transaction">事物</param>
        /// <param name="commandTimeout">连接时间</param>
        /// <returns></returns>
        public static int InsertTwo<T>(this DbBase dbs, T t, IDbTransaction transaction = null, int? commandTimeout = null) where T : class
        {
            var db = dbs.DbConnecttion;
            var sql = SqlQuery<T>.Builder(dbs);
            NewId identity = new NewId();

            string strSql = sql.InsertSql + ";SELECT LAST_INSERT_ID() as Id;";
            identity = db.Query<NewId>(strSql, t, transaction, true, commandTimeout, null).Single<NewId>();

            return identity.Id;
        }

        /// <summary>
        ///  批量插入数据
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="dbs"></param>
        /// <param name="lt"></param>
        /// <param name="transaction"></param>
        /// <param name="commandTimeout"></param>
        /// <returns></returns>
        public static bool InsertBatch<T>(this DbBase dbs, IList<T> lt, IDbTransaction transaction = null, int? commandTimeout = null) where T : class
        {
            var db = dbs.DbConnecttion;
            var sql = SqlQuery<T>.Builder(dbs);
            var flag = db.Execute(sql.InsertSql, lt, transaction, commandTimeout);
            return flag == lt.Count;
        }

        /// <summary>
        /// 按条件删除
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="dbs"></param>
        /// <param name="sql"></param>
        /// <returns></returns>
        public static bool Delete<T>(this DbBase dbs, SqlQuery sql = null) where T : class
        {
            var db = dbs.DbConnecttion;
            if (sql == null)
            {
                sql = SqlQuery<T>.Builder(dbs);
            }
            var f = db.Execute(sql.DeleteSql, sql.Param);
            return f > 0;
        }

        /// <summary>
        /// 修改
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="dbs"></param>
        /// <param name="t">如果sql为null，则根据t的主键进行修改</param>
        /// <param name="sql">按条件修改</param>
        /// <returns></returns>
        public static bool Update<T>(this DbBase dbs, T t, SqlQuery sql = null) where T : class
        {
            var db = dbs.DbConnecttion;
            if (sql == null)
            {
                sql = SqlQuery<T>.Builder(dbs);
            }
            sql = sql.AppendParam<T>(t);
            var f = db.Execute(sql.UpdateSql, sql.Param);
            return f > 0;
        }
        /// <summary>
        /// 修改
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="dbs"></param>
        /// <param name="t">如果sql为null，则根据t的主键进行修改</param>
        /// <param name="updateProperties">要修改的属性集合</param>
        /// <param name="sql">按条件修改</param>
        /// <returns></returns>
        public static bool Update<T>(this DbBase dbs, T t, IList<string> updateProperties, SqlQuery sql = null) where T : class
        {
            var db = dbs.DbConnecttion;
            if (sql == null)
            {
                sql = SqlQuery<T>.Builder(dbs);
            }
            sql = sql.AppendParam<T>(t)
                .SetExcProperties<T>(updateProperties);
            var f = db.Execute(sql.UpdateSql, sql.Param);
            return f > 0;
        }

        /// <summary>
        /// 修改
        /// </summary>
        /// <typeparam name="T">模型类型</typeparam>
        /// <param name="dbs">db</param>
        /// <param name="t">修改的数据</param>
        /// <param name="sql">修改的SQL语句</param>
        /// <returns></returns>
        public static bool Update<T>(this DbBase dbs, T t, string sql) where T : class
        {
            var db = dbs.DbConnecttion;
            var f = db.Execute(sql, t);
            return f > 0;
        }

 测试源代码如下

链接: https://pan.baidu.com/s/1dFlPHDJ 密码: ja8h