প্রথমে একটি উদাহরণ দেখি এবং একটি টেবিল তৈরি করা যাক:
mysql> create table DemoTable ( StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentName varchar(40), StudentAge int, StudentMarks int ); Query OK, 0 rows affected (0.76 sec)
ডেটাবেস স্ট্রাকচার জানার কোয়েরি:
mysql> show create table DemoTable;
এটি নিম্নলিখিত আউটপুট তৈরি করবে:
+---------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table | +---------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | DemoTable | CREATE TABLE `DemoTable` (`StudentId` int(11) NOT NULL AUTO_INCREMENT, `StudentName` archar(40) COLLATE utf8_unicode_ci DEFAULT NULL, `StudentAge` int(11) DEFAULT NULL, `StudentMarks` int(11) DEFAULT NULL, PRIMARY KEY (`StudentId`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci | +---------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.06 sec)
এখন ডেটাবেস স্ট্রাকচার পরিবর্তন করা যাক:
mysql> alter table DemoTable add column StudentCountryName varchar(20); Query OK, 0 rows affected (0.65 sec) Records : 0 Duplicates : 0 Warnings : 0
আমরা এখন আবার ডেটাবেস স্ট্রাকচার চেক করব:
mysql> show create table DemoTable;
এটি নিম্নলিখিত আউটপুট তৈরি করবে। এখন আমরা স্ট্রাকচারের পরিবর্তন মিলিয়ে নিতে পারি:
+---------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table | +---------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | DemoTable | CREATE TABLE `DemoTable` ( `StudentId` int(11) NOT NULL AUTO_INCREMENT, `StudentName` varchar(40) COLLATE utf8_unicode_ci DEFAULT NULL, `StudentAge` int(11) DEFAULT NULL, `StudentMarks` int(11) DEFAULT NULL, `StudentCountryName` varchar(20) COLLATE utf8_unicode_ci DEFAULT NULL, PRIMARY KEY (`StudentId`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci | +---------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)
