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 > 數據庫 > 文庫 > 正文

SQL嵌套查詢總結

2020-10-29 21:54:59
字體:
來源:轉載
供稿:網友
IT也有一段時間了,剛開始的時候``````
的困難主要是在編程語言上,數組,邏輯,算法,...
這些都過來了之后,困難就上升到數據庫設計上了.
以及數據邏輯.
一個優秀的系統,會集成優秀的程序和優秀的數據庫設計.
要做到這點得有足夠的經驗.
這是我寫的一個結合UINON的嵌套查詢.
將五個方面的報表放到一個臨時表里,再從臨時表里,將所要的數據查詢出來. 
復制代碼 代碼如下:

$sql="SELECT type , sum( yjsl ) as yjsl , sum( yysl ) as yysl, sum( jyrs ) as jyrs, sum( jycs ) as jycs
FROM (
SELECT c.mc AS
TYPE , count( d.lsh ) AS yjsl, 0 AS yysl, 0 AS jyrs, 0 AS jycs
FROM sys_dzxxb AS b, sys_jcb AS c, sys_dzyjb AS d
WHERE b.bm = c.lsh
AND d.dzlsh = b.lsh
GROUP BY c.mc
UNION SELECT c.mc AS
TYPE , 0 AS yjsl, count( e.lsh ) AS yysl, 0 AS jyrs, 0 AS jycs
FROM sys_dzxxb AS b, sys_jcb AS c, sys_dzyy AS e
WHERE b.bm = c.lsh
AND e.dzlsh = b.lsh
GROUP BY c.mc
UNION SELECT c.mc AS
TYPE , 0 AS yjsl, 0 AS yysl, count( DISTINCT e.dzlsh ) AS jyrs, 0 AS jycs
FROM sys_dzxxb AS b, sys_jcb AS c, sys_ltxxb AS e
WHERE b.bm = c.lsh
AND e.dzlsh = b.lsh
GROUP BY c.mc
UNION SELECT c.mc AS
TYPE , 0 AS yjsl, 0 AS yysl, 0 AS jyrs, count( DISTINCT e.lsh ) AS jycs
FROM sys_dzxxb AS b, sys_jcb AS c, sys_ltxxb AS e
WHERE b.bm = c.lsh
AND e.dzlsh = b.lsh
GROUP BY c.mc
) AS temptable
GROUP BY TYPE ";

分享給大家.
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: 木兰县| 德化县| 绥德县| 教育| 深圳市| 天峨县| 东至县| 伊宁县| 宝山区| 外汇| 秦皇岛市| 腾冲县| 若尔盖县| 卢氏县| 临江市| 利津县| 奉节县| 泸定县| 安顺市| 宜丰县| 万载县| 九寨沟县| 杨浦区| 日照市| 华池县| 汉源县| 海晏县| 灌云县| 青川县| 合水县| 阿鲁科尔沁旗| 册亨县| 自贡市| 开封市| 广东省| 高清| 即墨市| 格尔木市| 新蔡县| 夏邑县| 榆林市|