Bawo ni MySQL ṣe ṣẹda/ju tabili igba diẹ silẹ? Awọn ipa ti MySQL ibùgbé tabili

MySQLBawo ni lati ṣẹda / ju tabili iwọn otutu silẹ?MySQLAwọn ipa ti ibùgbé tabili

MySQL ibùgbé tabili

Tabili igba diẹ MySQL wulo pupọ nigba ti a nilo lati fi data igba diẹ pamọ.Awọn tabili igba diẹ han nikan ni asopọ lọwọlọwọ Nigbati asopọ ti wa ni pipade, Mysql yoo pa tabili rẹ laifọwọyi yoo tu gbogbo aaye silẹ.

Awọn tabili igba diẹ ni a ṣafikun ni ẹya MySQL 3.23. Ti ẹya MySQL rẹ ba kere ju ẹya 3.23, o ko le lo awọn tabili igba diẹ MySQL.Sibẹsibẹ, o jẹ toje lati lo iru ẹya kekere bayi.MySQL databaseiṣẹ.

Tabili igba diẹ MySQL han nikan si asopọ lọwọlọwọ Ti o ba lo iwe afọwọkọ PHP lati ṣẹda tabili igba diẹ MySQL, tabili igba diẹ yoo parun laifọwọyi nigbakugba ti iwe afọwọkọ PHP ti ṣiṣẹ.

Ti o ba lo eto alabara MySQL miiran lati sopọ si olupin data MySQL lati ṣẹda tabili igba diẹ, tabili igba diẹ yoo parun nigbati eto alabara ba wa ni pipade, dajudaju, o tun le pa a run pẹlu ọwọ.

Apeere

Atẹle yii fihan apẹẹrẹ ti o rọrun ti lilo tabili igba diẹ MySQL, koodu SQL atẹle le ṣee lo si iṣẹ mysql_query () ti iwe afọwọkọ 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）



                                   

  

nigba ti o ba loṢI TABINigbati aṣẹ ba ṣafihan atokọ ti awọn tabili data, iwọ kii yoo ni anfani lati wo tabili Summary Sales.

Ti o ba jade kuro ni igba MySQL lọwọlọwọ, lẹhinna loYanpipaṣẹ lati ka data tabili igba diẹ ti a ṣẹda ni akọkọ, lẹhinna iwọ yoo rii pe tabili ko si ninu ibi ipamọ data, nitori tabili igba diẹ ti bajẹ nigbati o ba jade.

Ju MySQL ibùgbé tabili

Nipa aiyipada, awọn tabili igba diẹ ti bajẹ laifọwọyi nigbati o ba ge asopọ lati ibi ipamọ data.Dajudaju o tun le lo ninu igba MySQL lọwọlọwọSINU TABIpipaṣẹ lati fi ọwọ silẹ tabili igba diẹ.

Atẹle jẹ apẹẹrẹ ti sisọ tabili igba diẹ silẹ pẹlu ọwọ:

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