Dapper1.5学习笔记1

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基本的Execute操作

注：ConnectViaOledb() 返回一个连接对象

获取一个连接的方法

protected static SqliteConnection GetSqliteConnection(bool open = true)        {            var connection = new SqliteConnection("Data Source=:memory:");            if (open) connection.Open();            return connection;        }

1，插入单条数据

 public void PseudoPositionalParameters_ExecSingle()        {            using (var connection = <span style="font-family: Arial, Helvetica, sans-serif;">GetSqliteConnection</span>( true )  )            {                var data = new { x = 6 };                connection.Execute("create table #named_single(val int not null)");                int count = connection.Execute("insert #named_single (val) values (?x?)", data);                int sum = (int)connection.ExecuteScalar("select sum(val) from #named_single");                count.IsEqualTo(1);                sum.IsEqualTo(6);            }        }

2，插入多条数据

 public void PseudoPositionalParameters_ExecMulti()        {            using (var connection = <span style="font-family: Arial, Helvetica, sans-serif;">GetSqliteConnection</span><span style="font-family: Arial, Helvetica, sans-serif;">( true )  </span><span style="font-family: Arial, Helvetica, sans-serif;">)</span>            {                var data = new[]                {                    new { x = 1, y = 1 },                    new { x = 3, y = 1 },                    new { x = 6, y = 1 },                };                connection.Execute("create table #named_multi(val int not null)");                int count = connection.Execute("insert #named_multi (val) values (?x?)", data);                int sum = (int)connection.ExecuteScalar("select sum(val) from #named_multi");                count.IsEqualTo(3);                sum.IsEqualTo(10);            }        }

3，查询

 public void Issue466_SqliteHatesOptimizations()        {            using (var connection = <span style="font-family: Arial, Helvetica, sans-serif;"> </span><span style="font-family: Arial, Helvetica, sans-serif;">GetSqliteConnection</span><span style="font-family: Arial, Helvetica, sans-serif;">( true )  </span><span style="font-family: Arial, Helvetica, sans-serif;">)</span>            {                SqlMapper.ResetTypeHandlers();                var row = connection.Query<HazNameId>("select 42 as Id").First();                row.Id.IsEqualTo(42);                row = connection.Query<HazNameId>("select 42 as Id").First();                row.Id.IsEqualTo(42);                SqlMapper.ResetTypeHandlers();                row = connection.QueryFirst<HazNameId>("select 42 as Id");                row.Id.IsEqualTo(42);                row = connection.QueryFirst<HazNameId>("select 42 as Id");                row.Id.IsEqualTo(42);            }        }

4，异步查询操作

  public async Task Issue466_SqliteHatesOptimizations_Async()        {            using (var connection = <span style="font-family: Arial, Helvetica, sans-serif;"> </span><span style="font-family: Arial, Helvetica, sans-serif;">GetSqliteConnection</span><span style="font-family: Arial, Helvetica, sans-serif;">( true )  </span><span style="font-family: Arial, Helvetica, sans-serif;">)</span>            {                SqlMapper.ResetTypeHandlers();                var row = (await connection.QueryAsync<HazNameId>("select 42 as Id")).First();                row.Id.IsEqualTo(42);                row = (await connection.QueryAsync<HazNameId>("select 42 as Id")).First();                row.Id.IsEqualTo(42);                SqlMapper.ResetTypeHandlers();                row = await connection.QueryFirstAsync<HazNameId>("select 42 as Id");                row.Id.IsEqualTo(42);                row = await connection.QueryFirstAsync<HazNameId>("select 42 as Id");                row.Id.IsEqualTo(42);            }        }

5，执行单个操作

 private void Isse467_SqliteParameterNaming(bool prefix)        {            using (var connection =<span style="font-family: Arial, Helvetica, sans-serif;"> </span><span style="font-family: Arial, Helvetica, sans-serif;">GetSqliteConnection</span><span style="font-family: Arial, Helvetica, sans-serif;">( true )  </span><span style="font-family: Arial, Helvetica, sans-serif;">)</span>            {                var cmd = connection.CreateCommand();                cmd.CommandText = "select @foo";#if NET40 || NET45                const DbType type = DbType.Int32;#else                const SqliteType type = SqliteType.Integer;#endif                cmd.Parameters.Add(prefix ? "@foo" : "foo", type).Value = 42;                var i = Convert.ToInt32(cmd.ExecuteScalar());                i.IsEqualTo(42);            }        }

6，单个查询操作query

        public void GetOnlyProperties()        {            using ( var connection = GetSqliteConnection( true )  )            {              var obj = connection.QuerySingle<HazGetOnly>("select 42 as [Id], 'def' as [Name];");              obj.Id.IsEqualTo(42);              obj.Name.IsEqualTo("def");            }        }        class HazGetOnly        {            public int Id { get; }            public string Name { get; } = "abc";        }

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