Dapper学习(三)之其他用法

这里说的其他用法，是指 Async,Buffered,Transaction,Stored Procedure。

1. 首先 dapper支持异步

ExecuteAsync, QueryAsync, QueryFirstAsync, QueryFirstOrDefaultAsync, QuerySingleAsync, QuerySingleOrDefaultAsync, QueryMultipleAsync

ExecuteAsync 用法示例：

string sql = "INSERT INTO Customers (CustomerName) Values (@CustomerName);";  using (var connection = new SqlConnection(FiddleHelper.GetConnectionStringSqlServerW3Schools())) {     var affectedRows = connection.ExecuteAsync(sql, new {CustomerName = "Mark"}).Result;      Console.WriteLine(affectedRows);      var customer = connection.Query<Customer>("Select * FROM CUSTOMERS WHERE CustomerName = 'Mark'").ToList();      FiddleHelper.WriteTable(customer); }

2. Buffered

默认是：True

A buffered query return the entire reader at once.

A non-bufferd query is equivalent as streaming. you only load objects on demand. That can be useful for a very large query to reduce memory usage.

string sql = "SELECT * FROM OrderDetails;";  using (var connection = new SqlConnection(FiddleHelper.GetConnectionStringSqlServerW3Schools())) {     var orderDetails = connection.Query<OrderDetail>(sql, buffered: false).ToList();      FiddleHelper.WriteTable(orderDetails.Take(10)); }

3. Transaction

dapper支持 transaction 和 TransactionScope

Transaction

使用示例如下：

string sql = "INSERT INTO Customers (CustomerName) Values (@CustomerName);";  using (var connection = new SqlConnection(FiddleHelper.GetConnectionStringSqlServerW3Schools())) {     connection.Open();          using (var transaction = connection.BeginTransaction())     {         var affectedRows = connection.Execute(sql, new {CustomerName = "Mark"}, transaction: transaction);                  transaction.Commit();                  Console.WriteLine(affectedRows);     } }

TransactionScope

在连接之前，使用 transaction scope

// using System.Transactions;  using (var transaction = new TransactionScope()) {     var sql = "Invoice_Insert";      using (var connection = My.ConnectionFactory())     {         connection.Open();          var affectedRows = connection.Execute(sql,             new {Kind = InvoiceKind.WebInvoice, Code = "Single_Insert_1"},             commandType: CommandType.StoredProcedure);     }      transaction.Complete(); }

4. Stored Procedure

在dapper中使用存储过程，只需要指定命令类型

var sql = "Invoice_Insert";  using (var connection = My.ConnectionFactory()) {     connection.Open();      var affectedRows = connection.Execute(sql,         new {Kind = InvoiceKind.WebInvoice, Code = "Single_Insert_1"},         commandType: CommandType.StoredProcedure);      My.Result.Show(affectedRows); }

dapperѧϰ

来源：博客园

作者：Vincent-yuan

链接：https://www.cnblogs.com/Vincent-yuan/p/11521148.html

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