1publicstaticvoidMySQLConn()2{3try4{5varresult = DapperHelper.Query<project>(DB.NS_DS,"select * from ds.project");6Console.WriteLine($"COUNT : {result.Count.ToString()}");7}8catch(Exception ex)9{10Console.WriteLine(ex.Message);11}12}1314publicstaticList<T> Query<T>(stringconnectionStr...
Dapper QueryAsync To execute the query asynchronously, Dapper provides theQueryAsyncmethod, an asynchronous version of theQuerymethod. language-csharp | varsql="SELECT * FROM Product WHERE CategoryID = @categoryID"; varproducts=(awaitconnection.QueryAsync(sql,new{categoryID=1})).ToList(); ...
//Dapper写法:传入参数值var products = cn .Query<Product>($@" SELECT * FROM Product WHERE Name LIKE @productName AND ProductSubcategoryID = @subCategoryId ORDER BY ProductId",new { productName, subCategoryId }); //DapperQueryBuilder:直接在查询语句插入值var products = cn .QueryBuilder($@"...
INSERT INTO Student (Name,Age,Gender) SELECT N'刘一',18,N'female' UNION SELECT N'陈二',19,N'female' UNION SELECT N'张三',18,N'male' UNION SELECT N'李四',19,N'male' UNION SELECT N'王五',18,N'male' UNION SELECT N'赵六',19,N'male' UNION SELECT N'孙七',19,N'female' ...
Dapper使用Query方法执行SQL查询并返回结果集。 using (IDbConnection db = new SqlConnection(connectionString)) { string sql = "SELECT * FROM Students"; var students = db.Query<Student>(sql).ToList(); } 1. 2. 3. 4. 5. 2. 插入数据 Dapper使用Execute方法执行插入操作。 using (IDbConnection db...
string query = "SELECT c.CustomerId, c.CustomerName, o.OrderId, o.TotalAmount " + "FROM Customers c " + "JOIN Orders o ON c.CustomerId = o.CustomerId"; var result = dbConnection.Query<Customer, Order, Customer>( query, (customer, order) => ...
QueryFirstOrDefault<TestClass>("select * from t_um_event where c_id=:Id", new { id = "1BA2BF30-658A-4A79-A179-05A77C527150" }); //int cnt = cn.Execute("update t_um_event set c_reg_time=:reg_time where c_id=:id", new { id = "CEA00DA2-79D2-48CC-A9E1-D3CBB3842...
管理数据库链接：建议在配置文件中管理数据库连接字符串，以便于管理和维护。使用Dapper操作PostgreSQL：SQL查询数据列表：使用Dapper执行SQL查询来获取数据列表。Dapper提供了简洁的API，可以通过Query方法执行SQL查询，并将结果映射为指定的对象列表。csharpusing ){var sql = "SELECT * FROM your_table";...
{varsql ="select * from T_Category A inner join T_Category B on A.Id=B.pid Left join T_Category C on B.Id=C.pid where A.catelevel='一级'"; Category category=null; Category child=null;varuser = _dapperhelper.Query<Category, Category, Category, Category>(sql, (u, ul,ull) =>...
{return connection.Query<T>(sql).ToList(); } }///<summary>///查询指定数据.///</summary>///<typeparam name="T">实体类型.</typeparam>///<param name="sql">传入sql执行语句.</param>///<param name="t">传入泛型类.</param>///<returns>类.</returns>publicstatic T Query<T>(string...