net代码中运行ExecuteScalar或ExecuteNonquery ado命令时,我们需要返回状态true或false。问候 浏览0提问于2012-11-04得票数 0 回答已采纳 1回答 ADO.NET: ExecuteScalar()连接问题 UserId; { } sccmd.ExecuteScalar(); sqlcon.Close附加信息: ExecuteScalar需要一个开放和可用的连接。连接的当前状态已关闭。 浏...
数据集不存在即行数为零 直接使用 Int32 count = (Int32) cmd.ExecuteScalar() 会出现“未将对象引用设置到 对象的实例”的ERROR 解决方式–> object obj = comm.ExecuteScalar(); if (obj == null ) MessageBox.Show(“数据集的行数为零”);
使用ExecuteScalar方法从数据库中检索单个值(例如一个聚合值)。与使用ExecuteReader方法,然后使用SqlDataReader返回的数据执行生成单个值所需的操作相比,此操作需要的代码较少。 典型的ExecuteScalar查询可以采用类似于下面的 C# 示例的格式: cmd.CommandText = "SELECT COUNT(*) FROM dbo.region"; Int32 count = (In...
Exception Thrown - Metadata dll file couldn't be found in VS Project execute HTTP url through c# code execute stored procedure based on button click Execute the C# code written in String ExecuteNonQuery requires an open and available Connection. ExecuteNonQuery requires an open and available Connectio...
ExecuteNonQuery Method Namespace:System.Data.SqlClient Return DataType: System.Int32 (number of rows affected) Use :You can use theExecuteNonQueryto perform catalog operations by executing UPDATE, INSERT, or DELETE statements. For UPDATE, INSERT, and DELETE statements, the return value is the numbe...
Exception Thrown - Metadata dll file couldn't be found in VS Project execute HTTP url through c# code execute stored procedure based on button click Execute the C# code written in String ExecuteNonQuery requires an open and available Connection. ExecuteNonQuery requires an open and available Connectio...