Ini boleh dijelaskan dengan contoh di mana kita mencipta lajur terjana yang disimpan dalam jadual bernama "data_pekerja_disimpan". Kami tahu bahawa lajur terjana yang disimpan boleh dijana dengan menggunakan kata kunci "disimpan".
mysql> Create table employee_data_stored(ID INT AUTO_INCREMENT PRIMARY KEY, First_name VARCHAR(50) NOT NULL, Last_name VARCHAR(50) NOT NULL, FULL_NAME VARCHAR(90) GENERATED ALWAYS AS(CONCAT(First_name,' ',Last_name)) STORED); Query OK, 0 rows affected (0.52 sec) mysql> DESCRIBE employee_data_stored; +------------+-------------+------+-----+---------+------------------+ | Field | Type | Null | Key | Default | Extra | +------------+-------------+------+-----+---------+------------------+ | ID | int(11) | NO | PRI | NULL | auto_increment | | First_name | varchar(50) | NO | | NULL | | | Last_name | varchar(50) | NO | | NULL | | | FULL_NAME | varchar(90) | YES | | NULL | STORED GENERATED | +------------+-------------+------+-----+---------+------------------+ 4 rows in set (0.00 sec) mysql> INSERT INTO employee_data_stored(first_name, Last_name) values('Gaurav','Kumar'); Query OK, 1 row affected (0.04 sec) mysql> INSERT INTO employee_data_stored(first_name, Last_name) values('Raman','Singh'); Query OK, 1 row affected (0.09 sec) mysql> Select * from employee_data_stored; +----+------------+-----------+--------------+ | ID | First_name | Last_name | FULL_NAME | +----+------------+-----------+--------------+ | 1 | Gaurav | Kumar | Gaurav Kumar | | 2 | Raman | Singh | Raman Singh | +----+------------+-----------+--------------+ 2 rows in set (0.00 sec)
Atas ialah kandungan terperinci Bagaimanakah MySQL disimpan GENERATED COLUMNS berfungsi dengan fungsi terbina dalam?. Untuk maklumat lanjut, sila ikut artikel berkaitan lain di laman web China PHP!