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法律研究如何檢測 MySQL 資料庫結構是否已更改（不是內容）？
讓我們首先看一個示例並建立一個表——
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)
以下是瞭解資料庫結構的查詢——
mysql> show create table DemoTable;
將會產生以下輸出——
+---------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | 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)
現在，讓我們更改資料庫結構——
mysql> alter table DemoTable add column StudentCountryName varchar(20); Query OK, 0 rows affected (0.65 sec) Records : 0 Duplicates : 0 Warnings : 0
現在，我們將再次檢查資料庫結構——
mysql> show create table DemoTable;
將會產生以下輸出。我們現在可以匹配結構中的更改——
+---------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | 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)
更新於：06-Jul-2020
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