Kodi MySQL imapanga / kugwetsa bwanji tebulo kwakanthawi? Udindo wa matebulo osakhalitsa a MySQL

Kodi mungapange/kuchotsa tebulo lachikhalire mu MySQL ? Cholinga cha matebulo achikhalire a MySQL n'chiyani?

MySQL temporary table

Matebulo osakhalitsa a MySQL ndi othandiza kwambiri tikafunika kusunga kwakanthawi kochepa.Matebulo osakhalitsa amangowoneka pamalumikizidwe apano. Kulumikizana kukatsekedwa, Mysql imangochotsa tebulo ndikumasula malo onse.

Matebulo osakhalitsa adawonjezedwa mu MySQL version 3.23. Ngati MySQL yanu ili yocheperapo kuposa 3.23, simudzatha kugwiritsa ntchito matebulo osakhalitsa a MySQL. Komabe, mitundu yotsika ngati imeneyi ya mautumiki a database a MySQL sagwiritsidwa ntchito kawirikawiri masiku ano.

Tebulo losakhalitsa la MySQL limangowoneka ndi kulumikizana komwe kulipo.Ngati mugwiritsa ntchito PHP script kuti mupange tebulo losakhalitsa la MySQL, tebulo losakhalitsa liziwonongeka nthawi iliyonse yomwe script ya PHP yalembedwa.

Ngati mugwiritsa ntchito pulogalamu ina yamakasitomala a MySQL kuti mulumikizane ndi seva ya database ya MySQL kuti mupange tebulo lanthawi yochepa, tebulo losakhalitsa lidzawonongeka pokhapokha pulogalamu ya kasitomala ikatsekedwa.Zowona, mutha kuwononganso pamanja.

Chitsanzo

Zotsatirazi zikuwonetsa chitsanzo chophweka chogwiritsira ntchito tebulo lachidule la MySQL, SQL code yotsatira ingagwiritsidwe ntchito pa mysql_query () ntchito ya PHP script.

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）



                                   

  

Mukagwiritsa ntchito lamulo la SHOW TABLES kuti muwonetse mndandanda wa matebulo, simudzawona tebulo la SalesSummary.

Ngati mutatuluka mu gawo la MySQL lomwe lilipo kenako nkugwiritsa ntchito lamulo la SELECT kuti muwerenge deta kuchokera pa tebulo lakanthawi lomwe lidapangidwa kale, mupeza kuti tebulolo silikupezeka mu database chifukwa tebulo lakanthawi linawonongeka pamene mudatuluka.

Chotsani MySQL temporary table

Mwachisawawa, matebulo osakhalitsa amawonongeka okha mukachotsa deta yanu kuchokera ku database. Kapena, mutha kuchotsa matebulo osakhalitsa pamanja mkati mwa gawo la MySQL lomwe likugwiritsidwa ntchito pano pogwiritsa ntchito lamulo la DROP TABLE .

Chotsatirachi ndi chitsanzo cha kugwetsa tebulo losakhalitsa pamanja:

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