zoukankan      html  css  js  c++  java
  • SQL 学习(二)INNER JOIN

    通过SQL 联表查询:(一看就明白)

     private void Form1_Load(object sender, EventArgs e)
            {
                SqlConnection con = new SqlConnection(@"Data Source=myServer;Initial Catalog=Northwind;Integrated Security=True;");//数据连接字符串
                SqlDataAdapter dap = new SqlDataAdapter("SELECT Orders.OrderID, Customers.CompanyName, Orders.OrderDate FROM Orders INNER JOIN Customers ON Orders.CustomerID=Customers.CustomerID", con);       //INNER JOIN     
                DataSet ds = new DataSet();
                dap.Fill(ds, "table");
                dataGridView1.DataSource = ds.Tables[0].DefaultView;
            }

    联接ACCESS数据库进行多表查询:
            private void Form1_Load(object sender, EventArgs e)
            {
                        
               OleDbConnection conn = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=myDataBase.accdb;");
               OleDbDataAdapter dap = new OleDbDataAdapter("SELECT Course.course, Course.classroom, Faculty.faculty_name,Faculty.office,Faculty.email FROM Faculty INNER JOIN Course ON Faculty.faculty_id = Course.faculty_id",conn);
               DataSet ds = new DataSet();
               dap.Fill(ds);
               dataGridView1.DataSource = ds.Tables[0].DefaultView;
            }

  • 相关阅读:
    python中的深拷贝和浅拷贝
    Andrew NG 机器学习编程作业6 Octave
    Andrew NG 机器学习编程作业5 Octave
    梯度下降算法对比(批量下降/随机下降/mini-batch)
    无监督算法
    深度学习的方差与偏差
    Andrew NG 机器学习编程作业4 Octave
    数据约束
    数据库的查询
    MySQL的入门与使用,sqlyog对数据库,表和数据的管理
  • 原文地址:https://www.cnblogs.com/lbs8/p/3594043.html
Copyright © 2011-2022 走看看