如何在SQL和C＃中只插入一个ID的五个值

本文介绍了如何在SQL和C＃中只插入一个ID的五个值的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 我想为每个学生添加五个主题标记...我将如何限制Stduent_ID？如果Stduent_ID = 1并且插入五次然后六个条目我不应该添加...我将如何在C＃中执行此操作+ SQL ... 我的尝试： 声明@Counter int 设置@ Counter =（SELECT Count（Student_ID）为'StudentCount' 来自CourseSemOne 其中Student_ID = 3 Group by Student_ID ） if（@Counter> = 6） print'Sorry！你不能为一个stduent添加超过五个主题数据' 其他 打印'插入查询'解决方案 minor correction if （ @ Counter > = 5 ） string sql = SELECT Count（Student_ID）FROM CourseSemOne，其中Student_ID ='" + Student_ID +"'Group by Student_ID" ;; SqlConnection con = new SqlConnection（@Data Source = LOCALHOST \ SQLEXPRESS;初始目录= CS_DB;集成安全性=真）; con.Open（）; SqlCommand cmd = new SqlCommand（sql，con）; int count = Convert.ToInt32（cmd.ExecuteScalar（））; con.Close（）; if （计数< 5&& count> = 0） { obj.insertSemCourseOne（Student_ID，Course_Code，Course_Title，Total_Marks，Obtain_Marks，Grade，Value，Cr_Hours，Grade_Point，GPA，CGPA）; // DatabaseConnnectionClass.UserMessage（" Added"）; MessageBox.Show（" Added Subject"）; Dataloaddd（）; } 其他 { MessageBox.Show（&抱歉！对于这个学号=" + Student_ID +"您不能添加超过5个数据。）; } i want to add only five subject marks for each student...how i will restrict an Stduent_ID ?if Stduent_ID=1 and inserted five times then for six entry i should not add...how i will do it in C# + SQL...What I have tried:Declare @Counter int Set @Counter=(SELECT Count(Student_ID) as 'StudentCount'FROM CourseSemOne where Student_ID=3 Group by Student_ID )if(@Counter >= 6)print'Sorry! You cannot add more than five subject data for a single stduent'elseprint 'Insert Query' 解决方案 minor correctionif(@Counter >= 5)string sql = "SELECT Count(Student_ID) FROM CourseSemOne where Student_ID='"+Student_ID+"' Group by Student_ID "; SqlConnection con = new SqlConnection(@"Data Source=LOCALHOST\SQLEXPRESS;Initial Catalog=CS_DB;Integrated Security=True"); con.Open(); SqlCommand cmd = new SqlCommand(sql, con); int count = Convert.ToInt32(cmd.ExecuteScalar()); con.Close(); if (count <5 && count >=0) { obj.insertSemCourseOne(Student_ID, Course_Code, Course_Title, Total_Marks, Obtain_Marks, Grade, Value, Cr_Hours, Grade_Point, GPA, CGPA); // DatabaseConnnectionClass.UserMessage("Added"); MessageBox.Show("Added Subject"); Dataloaddd(); } else { MessageBox.Show("Sorry!For this Student ID = "+Student_ID+" You cannot add more than 5 data."); } 这篇关于如何在SQL和C＃中只插入一个ID的五个值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！