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  • C# 查询一个值方法ExecuteScalar()

    需要从SQL查询中返回一个值,如表中记录数。可以使用ExecuteScalar()方法,这个方法只返回一个值。如下边控制台应用程序代码所示:

    using System.Data;
    using System.Data.SqlClient;

    namespace ExecuteScalar
    {
        
    class Program
        {
            
    static void Main(string[] args)
            {
                SqlConnection thisConnection 
    = new SqlConnection(
         
    @"Data Source=scott;Initial Catalog=northwind;Persist Security Info=True;User ID=sa;Password=sa123");

                thisConnection.Open();

                SqlCommand thisCommand 
    = thisConnection.CreateCommand();
                thisCommand.CommandText 
    = "select count(*) from customers";

                
    //ExecuteScalar:执行只返回一个值的SQL命令。
                object countResult = thisCommand.ExecuteScalar();
                Console.WriteLine(
    "Count of Customers={0}",countResult);

                Console.ReadLine();

                thisConnection.Close();
            }
        }
    }

    结果为:

     Count of Customers=91

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  • 原文地址:https://www.cnblogs.com/jhabb/p/1880438.html
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