学步园

       1. 说明：复制表(只复制结构，源表名：a，新表名：b) 
SQL: select * into b from a where 1<>1; 
        2. 说明：拷贝表(拷贝数据，源表名：a，目标表名：b) 
SQL: insert into b(a, b, c) select d, e, f from b; 
        3. 说明：显示文章、提交人和最后回复时间 
SQL: select a.title, a.username, b.adddate 
     from table a,(
          select max(adddate) adddate 
          from table where table.title=a.title) b 　
 
        4. 说明：外连接查询(表名1：a，表名2：b) 
SQL: select a.a, a.b, a.c, b.c, b.d, b.f 
     from a LEFT OUT JOIN b ON a.a = b.c; 　
 
        5. 说明：日程安排提前五分钟提醒 
SQL: select * 
     from 日程安排 
     where datediff(’’minute’’, f开始时间, getdate())>5 　　
 
　　 
        6. 说明：两张关联表，删除主表中已经在副表中没有的信息 
SQL: delete from info 
     where not exists(
           select * 
           from infobz 
           where info.infid=infobz.infid );
 
        7. 说明：—— 
SQL: SELECT A.NUM, A.NAME, B.UPD_DATE, B.PREV_UPD_DATE 
     FROM TABLE1,(SELECT X.NUM, X.UPD_DATE, Y.UPD_DATE PREV_UPD_DATE 
                  FROM (SELECT NUM, UPD_DATE, INBOUND_QTY, STOCK_ONHAND 
                        FROM TABLE2 
                        WHERE TO_CHAR(UPD_DATE,’’YYYY/MM’’) = 
                              TO_CHAR(SYSDATE, ’’YYYY/MM’’)) X, 
                       (SELECT NUM, UPD_DATE, STOCK_ONHAND 
                        FROM TABLE2 
                        WHERE TO_CHAR(UPD_DATE,’’YYYY/MM’’) = 
                              TO_CHAR(TO_DATE(TO_CHAR(SYSDATE, ’’YYYY/MM’’) 
                              || ’’/01’’,’’YYYY/MM/DD’’) - 1, ’’YYYY/MM’’) ) Y, 
                   WHERE X.NUM = Y.NUM （+）AND X.INBOUND_QTY 
                                 + NVL(Y.STOCK_ONHAND,0) <> X.STOCK_ONHAND ) B 
                   WHERE A.NUM = B.NUM;　
 
　　 
        8. 说明：—— 
SQL: select * 
     from studentinfo 
     where not exists(select * from student where studentinfo.id=student.id) 
           and 系名称=’’"&strdepartmentname&"’’
           and 专业名称=’’"&strprofessionname&"’’
     order by 性别, 生源地, 高考总成绩;