Dalabka midowga iyadoo la adeegsanayo syntax/hadalka adeegsiga xogta MySQL

Xogta MySQL MINUUNKA AMARKA BY su'aasha naxwaha/isticmaalka weedha

MySQL Hawlwadeenka UNION

Casharadani waxa ay ku baraysaa hab-raacyada iyo tusaalooyinka hawlwadeenka MySQL UNION.

sharaxaad

Hawl wadeenka MySQL UNION waxa loo isticmaalaa in lagu daro natiijooyinka laba ama in ka badan oo ah SELECT weedho oo laga dhigo hal natiijo.Odhaahyo badan oo SELECT ayaa meesha ka saaraya xogta nuqul ka mid ah

naxwaha

MySQL UNION qaabka syntax hawlwadeenka:

SELECT expression1, expression2, ... expression_n
FROM tables
[WHERE conditions]
UNION [ALL | DISTINCT]
SELECT expression1, expression2, ... expression_n
FROM tables
[WHERE conditions];

Xusuus

• tibaax1, tibaax2, ... tibaax_n: Sadar si loo soo saaro.
• miisaska: Jadwalka xogta si loo soo saaro.
• Halkee shuruudaha: Ikhtiyaar ah, shuruudaha raadinta.
• KALA DUWAN: Ikhtiyaar ahaan, ka saar xogta nuqul ka mid ah natiijada.Hawl wadeenka UNION wuxuu si caadi ah u kala saaray xogta, markaa wax ka beddelka DISTINCT wax saamayn ah kuma laha natiijada.
• DHAMMAAN: Ikhtiyaar ah, soo celisa dhammaan natiijada natiijooyinka, oo ay ku jiraan nuqullo.

database demo

Tababarkan, waxaan ku isticmaali doonaa xogta muunada chenweiliang.

Waa kan xogta laga helay miiska "Websites":

mysql> SELECT * FROM Websites;
+----+--------------+---------------------------+-------+---------+
| id | name         | url                       | alexa | country |
+----+--------------+---------------------------+-------+---------+
| 1  | Google       | https://www.google.cm/    | 1     | USA     |
| 2  | 淘宝          | https://www.taobao.com/   | 13    | CN      |
| 3  | 陈沩亮博客      | http://www.chenweiliang.com/    | 4689  | CN      |
| 4  | 微博          | http://weibo.com/         | 20    | CN      |
| 5  | Facebook     | https://www.facebook.com/ | 3     | USA     |
| 7  | stackoverflow | http://stackoverflow.com/ |   0 | IND     |
+----+---------------+---------------------------+-------+---------+

Waa kan xogta "apps" APP:

mysql> SELECT * FROM apps;
+----+------------+-------------------------+---------+
| id | app_name   | url                     | country |
+----+------------+-------------------------+---------+
|  1 | QQ APP     | http://im.qq.com/       | CN      |
|  2 | 微博 APP | http://weibo.com/       | CN      |
|  3 | 淘宝 APP | https://www.taobao.com/ | CN      |
+----+------------+-------------------------+---------+
3 rows in set (0.00 sec)

Tusaale ahaan SQL UNION

Bayaanka SQL ee soo socda wuxuu ka soo xulaa dhammaan waddamada kala duwan (qiimayaal kala duwan oo keliya) jadwalka "Mareegaha" iyo "abka" :

SELECT country FROM Websites
UNION
SELECT country FROM apps
ORDER BY country;

SQL UNION ALL tusaale ahaan

Bayaanka SQL ee soo socda wuxuu adeegsadaa UNION ALL si uu u xusho dhammaan waddamada (oo ay ku jiraan qiimayaasha nuqulka ah) jadwalka "Websites" iyo "apps" :

SELECT country FROM Websites
UNION ALL
SELECT country FROM apps
ORDER BY country;

SQL UNION DHAMMAAN oo leh HALKEE

Bayaanka SQL ee soo socda wuxuu adeegsadaa UNION ALL si uu u doorto dhammaan xogta Shiinaha (CN) jadwalka "Websites" iyo "apps" (oo ay ku jiraan qiimayaasha nuqulka ah):

SELECT country, name FROM Websites
WHERE country='CN'
UNION ALL
SELECT country, app_name FROM apps
WHERE country='CN'
ORDER BY country;