I-MySQL idala/yehlisa kanjani itafula lesikhashana? Iqhaza lamathebula esikhashana e-MySQL

MySQLUngadala/uwisa kanjani ithebula lesikhashana?MySQLIqhaza lamatafula esikhashana

Ithebula lesikhashana le-MySQL

Amathebula esikhashana e-MySQL awusizo kakhulu lapho sidinga ukugcina idatha yesikhashana.Amathebula esikhashana abonakala kuphela ekuxhumekeni kwamanje. Uma uxhumano luvaliwe, i-Mysql izosusa ngokuzenzakalelayo ithebula futhi ikhulule sonke isikhala.

Amathebula esikhashana engezwe kunguqulo 3.23 ye-MySQL. Uma inguqulo yakho ye-MySQL ingaphansi kwenguqulo 3.23, awukwazi ukusebenzisa amathebula esikhashana e-MySQL.Nokho, akuvamile ukusebenzisa inguqulo ephansi kangaka manje.MySQL databaseisevisi.

Ithebula lesikhashana le-MySQL libonakala kuphela ekuxhumekeni kwamanje. Uma usebenzisa iskripthi se-PHP ukuze udale ithebula lesikhashana le-MySQL, ithebula lesikhashana lizobhujiswa ngokuzenzakalelayo noma nini lapho umbhalo we-PHP wenziwe.

Uma usebenzisa olunye uhlelo lweklayenti le-MySQL ukuze uxhume kusizindalwazi sesizindalwazi se-MySQL ukuze udale ithebula lesikhashana, ithebula lesikhashana lizobhujiswa kuphela lapho uhlelo lweklayenti luvaliwe. Yebo, ungakwazi futhi ukulicekela phansi mathupha.

Isibonelo

Okulandelayo kubonisa isibonelo esilula sokusebenzisa ithebula lesikhashana le-MySQL, ikhodi elandelayo ye-SQL ingasetshenziswa kumsebenzi we-mysql_query() wombhalo we-PHP.

MySQL的> CREATE TEMPORARY TABLE SalesSummary （- > PRODUCT_NAME VARCHAR （50 ）NOT NULL
     - > ，TOTAL_SALES DECIMAL （12 ，2 ）NOT NULL DEFAULT 0.00 - > ，avg_unit_price DECIMAL （7 ，2 ）NOT NULL DEFAULT 0.00 - > ，total_units_sold INT UNSIGNED NOT NULL DEFAULT 0 ）; 查询OK ，0 行受影响（0.00 秒 
     
     
     

 ）

的MySQL > INSERT INTO SalesSummary - > （PRODUCT_NAME ，TOTAL_SALES ，avg_unit_price ，total_units_sold ）- > VALUES
     - > （'黄瓜' ，100.25 ，90 ，2 ）;
     
        

mysql > SELECT * FROM SalesSummary ; + -------------- + ------------- + ---------------- + --- --------------- + | product_name | total_sales | avg_unit_price | total_units_sold | + -------------- + ------------- + ---------------- + --- --------------- + | 黄瓜      | 100.25 | 90.00 | 2 | + -------------- + ------------- + ---------------- + --- --------------- + 1 行中集合（0.00 秒）



                                   

  

uma usebenzisaBONISA AMABHALALapho umyalo ubonisa uhlu lwamathebula edatha, ngeke ukwazi ukubona ithebula le-SalesSummary.

Uma uphuma kuseshini yamanje ye-MySQL, bese usebenzisaKHETHAumyalo wokufunda idatha yetafula yesikhashana eyakhiwe ekuqaleni, khona-ke uzothola ukuthi ithebula alikho ku-database, ngoba ithebula lesikhashana libhujisiwe lapho uphuma.

Yehlisa ithebula lesikhashana le-MySQL

Ngokuzenzakalelayo, amathebula esikhashana abhujiswa ngokuzenzakalelayo lapho unqamula kusizindalwazi.Yebo ungasebenzisa futhi kuseshini yamanje ye-MySQLDROP TABLEumyalo wokuwisa ngokwakho ithebula lesikhashana.

Okulandelayo isibonelo sokuwisa ithebula lesikhashana mathupha:

mysql> CREATE TEMPORARY TABLE SalesSummary (
    -> product_name VARCHAR(50) NOT NULL
    -> , total_sales DECIMAL(12,2) NOT NULL DEFAULT 0.00
    -> , avg_unit_price DECIMAL(7,2) NOT NULL DEFAULT 0.00
    -> , total_units_sold INT UNSIGNED NOT NULL DEFAULT 0
);
Query OK, 0 rows affected (0.00 sec)

mysql> INSERT INTO SalesSummary
    -> (product_name, total_sales, avg_unit_price, total_units_sold)
    -> VALUES
    -> ('cucumber', 100.25, 90, 2);

mysql> SELECT * FROM SalesSummary;
+--------------+-------------+----------------+------------------+
| product_name | total_sales | avg_unit_price | total_units_sold |
+--------------+-------------+----------------+------------------+
| cucumber     |      100.25 |          90.00 |                2 |
+--------------+-------------+----------------+------------------+
1 row in set (0.00 sec)
mysql>DROP TABLE SalesSummary ; 
mysql >   SELECT * FROM SalesSummary ; 
错误1146 ：表'chenweiliang.SalesSummary' 不存在