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How to detect if a MySQL database structure changed (not content)?
Let us first see an example and create a table −
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)
Following is the query to know the database structure −
mysql> show create table DemoTable;
This will produce the following output −
+---------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | 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)
Now, let us change the database structure −
mysql> alter table DemoTable add column StudentCountryName varchar(20); Query OK, 0 rows affected (0.65 sec) Records : 0 Duplicates : 0 Warnings : 0
We will now check the database structure once again −
mysql> show create table DemoTable;
This will produce the following output. We can now match the changes in the structure −
+---------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | 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)
Updated on: 06-Jul-2020
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