SQL »ù±¾²Ù×÷ ɾ³ý ÐÞ¸Ä Ë¢Ð Ð޸İæ
C# Êý¾Ý¿âÖ®ÂÃ……
¼ÌÐø½ø¹¥²ã³ö²»ÇîµÄproblems
ÔÚÉÏһƪÄÚÈݵĻù´¡ÉÏ£¬ÎÒÓÖ×÷ÒԸĽø£¬ÏÖÔÚµÄÇé¿öÊÇÕâÑùµÄ£º
//In Browseuser form
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Configuration;
using System.Data.SqlClient;
namespace Str
{
public partial class Browseuser : Form
{
public Browseuser()
{
InitializeComponent();
}
//define Êý¾Ý¼¯¶ÔÏódsÓÃÓÚ±£´æ²éѯ·µ»ØµÄ½á¹û¼¯
DataSet ds;
private void Browseuser_Load(object sender, EventArgs e)
{
string strConnection = ConfigurationSettings.AppSettings["connectionstring"];
SqlConnection objConnection = new SqlConnection(strConnection);
objConnection.Open();
string sql = "select userid as userid,name as name from judging";
SqlDataAdapter adp = new SqlDataAdapter(sql, objConnection);
ds = new DataSet();
ds.Clear();
adp.Fill(ds, "judging");
dataGridView1.DataSource=ds. Tables[0].DefaultView;
dataGridView1.Refresh();
this.judgingTableAdapter.Fill(this.masterDataSet.judging);
}
/**********************************************************************************************/
/*ÖÁ´ËÍê³ÉÁ˽«Êý¾Ý¿âjudgingÖеÄÄÚÈÝÈ«²¿ÏÔʾÔÚÐÂform——BrowseuserÉÏ*/
/**********************************************************************************************/
private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
{
}
private void button3_Click(object sender, EventArgs e)
{
this.Close();
}
//define a delegate instance in order to refresh
delegate void UseF();
/****************
Ïà¹ØÎĵµ£º
1¡¢join
A±íµÄÖ÷¼üÊÇ×÷ΪB±íµÄÍâ¼ü¡£ÔÚ²éѯµÄʱºò£¬¿ÉÒÔͨ¹ý²»Í¬µÄjoin½«AºÍB±íÁ´½ÓÆðÀ´£¬´Ó¶øµÃµ½²»Í¬µÄ²éѯ½á¹û¡£
* JOIN: Èç¹û±íÖÐÓÐÖÁÉÙÒ»¸öÆ¥Å䣬Ôò·µ»ØÐÐ
* INNER JOIN: Èç¹ûÁ½¸ö±íÖÐÓÐÆ¥ÅäµÄ£¬Ôò·µ»ØÐÐ
* LEFT JOIN: ¼´Ê¹ÓÒ±íÖÐûÓÐÆ¥Å䣬Ҳ´Ó×ó± ......
ÉÏ´Î×öÁ˸öÏîÄ¿£¬Éæ¼°µ½Êý¾Ý¿âµÄ»¹ÔºÍ»Ö¸´£¬µ½ÍøÉÏÕÒÁËһϣ¬ÊÇÀûÓÃSQLDMOʵÏֵģ¬Ö»ÒªÌí¼ÓSQLDMOÒýÓþͺÃÁË£¬È»ºóÀûÓÃϱߵÄÀàµÄ·½·¨¾Í¿ÉÒÔʵÏÖÁË¡£
¡¡¡¡ÎÒ°ÑÔ×÷ÕßµÄÀàÀ©³äÁËһϣ¬¿ÉÒÔ×Ô¶¯Ê¶±ðweb.configÀï µÄÊý¾Ý¿âÁ¬½Ó×Ö·û´®£¬¿ÉÒÔͨ¹ý±äÁ¿ÉèÖû¹Ô»Ö¸´µÄÐÅÏ¢¡£
¡¡¡¡ÐèҪעÒâµÄʱ»¹Ô£¬»¹ÔµÄʱºòÎÊÌâ×î´óÁË£¬Óбð ......
ÔÚ¹¤×÷ÖÐÓöµ½Ò»¸öÎÊÌâ,ÊÇÐèÒªsqlµÝ¹é²éѯµÄ.²»¶®,ÓÚÊǵ½csdnÉÏÈ¥ÎÊ,ÄÇÀïµÄЧÂÊÕæÊǷdz£¸ß,ÎÒÒÔǰҲûÔÚÉÏÃæÎʹýÎÊÌâ.
ÎÊÌâÃèÊö:
ÎÒÓÐÒ»¸ö±í½á¹¹ÈçÏÂ:
id upperid
1 2
3 2
4 1
5 3
¾ßÌå²ã´Î²»ÖªµÀ,ÎÒÏëÓõݹésqlÓ ......
Student(S#,Sname,Sage,Ssex) ѧÉú±í
Course(C#,Cname,T#) ¿Î³Ì±í
SC(S#,C#,score) ³É¼¨±í
Teacher(T#,Tname) ½Ìʦ±í
ÎÊÌ⣺
1¡¢²éѯ“001”¿Î³Ì±È“002”¿Î³Ì³É¼¨¸ßµÄËùÓÐѧÉúµÄѧºÅ£»
select a.S# from (select s#,score from SC where C#='001') a,(select s#,score
& ......
ʹÓÃSQLÓï¾ä
SQLÓïÑÔ°üÀ¨Êý¾Ý²éѯÓïÑÔ(SELECT)¡¢Êý¾Ý²Ù×ÝÓïÑÔ(INSERT¡¢UPDATE¡¢DELETE)¡¢ÊÂÎñ¿ØÖÆÓïÑÔ(COMMIT¡¢ROLLBACK¡¢SAVEPOINT)¡¢Êý¾Ý¶¨ÒåÓïÑÔ(CREATE TABLE¡¢ALTER TABLE¡¢DROP)¡¢Êý¾Ý¿ØÖÆÓïÑÔ(GRANT¡¢REVOKE)µÈÎå¸ö²¿·Ö¡£
µ±±àдPL/SQLÓ¦ÓóÌÐòʱ£¬Ö»ÄÜÖ±½ÓǶÈëSELECT ......