国产探花免费观看_亚洲丰满少妇自慰呻吟_97日韩有码在线_资源在线日韩欧美_一区二区精品毛片,辰东完美世界有声小说,欢乐颂第一季,yy玄幻小说排行榜完本

首頁 > 開發 > 綜合 > 正文

精妙SQL語句介紹

2024-07-21 02:33:23
字體:
來源:轉載
供稿:網友
  如何從一位菜鳥蛻變成為高手,靈活使用的SQL語句是必不可少的。本文收集了部分比較經典,常用的SQL語句供大家參考,希望對大家有所幫助。  說明:復制表(只復制結構,源表名:a 新表名:b)    SQL: select * into b from a where 1<>1   說明:拷貝表(拷貝數據,源表名:a 目標表名:b)    SQL: insert into b(a, b, c) select d,e,f from b;  說明:顯示文章、提交人和最后回復時間    SQL: select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b  說明:外連接查詢(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  說明:日程安排提前五分鐘提醒    SQL: select * from 日程安排 where datediff('minute',f開始時間,getdate())>5    說明:兩張關聯表,刪除主表中已經在副表中沒有的信息  SQL:     delete from info where not exists ( select * from infobz where info.infid=infobz.infid  說明:--  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') &brvbar;&brvbar; '/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  說明:--  SQL:     select * from studentinfo where not exists(select * from student where studentinfo.id=student.id) and 系名稱='"&strdepartmentname&"' and 專業名稱='"&strprofessionname&"' order by 性別,生源地,高考總成績  說明:  從數據庫中去一年的各單位電話費統計(電話費定額賀電化肥清單兩個表來源)  SQL:    SELECT a.userper, a.tel, a.standfee, TO_CHAR(a.telfeedate, 'yyyy') AS telyear,   SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '01', a.factration)) AS JAN,   SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '02', a.factration)) AS FRI,   SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '03', a.factration)) AS MAR,   SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '04', a.factration)) AS APR,   SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '05', a.factration)) AS MAY,   SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '06', a.factration)) AS JUE,   SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '07', a.factration)) AS JUL,   SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '08', a.factration)) AS AGU,   SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '09', a.factration)) AS SEP,   SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '10', a.factration)) AS OCT,   SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '11', a.factration)) AS NOV,   SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '12', a.factration)) AS DEC
  FROM (SELECT a.userper, a.tel, a.standfee, b.telfeedate, b.factration   FROM TELFEESTAND a, TELFEE b   WHERE a.tel = b.telfax) a  GROUP BY a.userper, a.tel, a.standfee, TO_CHAR(a.telfeedate, 'yyyy')  說明:四表聯查問題:    SQL: select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where .....  說明:得到表中最小的未使用的ID號  SQL:   SELECT (CASE WHEN EXISTS(SELECT * FROM Handle b WHERE b.HandleID = 1) THEN MIN(HandleID) + 1 ELSE 1 END) as HandleID   FROM Handle   WHERE NOT HandleID IN (SELECT a.HandleID - 1 FROM Handle a) 

發表評論 共有條評論
用戶名: 密碼:
驗證碼: 匿名發表
主站蜘蛛池模板: 洛宁县| 吉水县| 宜阳县| 安乡县| 新和县| 和平区| 西丰县| 莱州市| 正定县| 都江堰市| 平阴县| 凤山市| 焦作市| 射洪县| 内江市| 新田县| 商洛市| 嵊州市| 罗定市| 黎川县| 铜鼓县| 时尚| 越西县| 平山县| 余庆县| 福建省| 平武县| 邢台市| 绍兴市| 信丰县| 吴忠市| 鄂托克旗| 绥阳县| 平和县| 双鸭山市| 卫辉市| 叶城县| 姜堰市| 嘉义县| 雷州市| 滕州市|