MySQLデータベースから制約のリストを取得しますか?
MySQLデータベースから制約のリストを取得するには、次の構文を使用します-
select *from information_schema.table_constraints where constraint_schema = 'yourDatabaseName';
ここでは、データベース「ビジネス」から制約を取得します。以下は、データベース「ビジネス」内のすべてのテーブルの制約を一覧表示するためのクエリです-
mysql> select * −> from information_schema.table_constraints −> where constraint_schema = 'business';
以下は、すべての制約を表示する出力です-
+--------------------+-------------------+--------------------------+--------------+------------------------------+-----------------+ | CONSTRAINT_CATALOG | CONSTRAINT_SCHEMA | CONSTRAINT_NAME | TABLE_SCHEMA | TABLE_NAME | CONSTRAINT_TYPE | +--------------------+-------------------+--------------------------+--------------+------------------------------+-----------------+ | def | business | PRIMARY | business | primarytable | PRIMARY KEY | | def | business | PRIMARY | business | primarytable1 | PRIMARY KEY | | def | business | PRIMARY | business | autoincrementtable | PRIMARY KEY | | def | business | PRIMARY | business | demoauto | PRIMARY KEY | | def | business | PRIMARY | business | autoincrement | PRIMARY KEY | | def | business | PRIMARY | business | primarytabledemo | PRIMARY KEY | | def | business | PRIMARY | business | sequencedemo | PRIMARY KEY | | def | business | PRIMARY | business | updtable | PRIMARY KEY | | def | business | PRIMARY | business | transcationdemo | PRIMARY KEY | | def | business | PRIMARY | business | triggedemo | PRIMARY KEY | | def | business | PRIMARY | business | usernameandpassworddemo | PRIMARY KEY | | def | business | UserId | business | usernameandpassworddemo | UNIQUE | | def | business | PRIMARY | business | tblp | PRIMARY KEY | | def | business | name | business | uniquedemo | UNIQUE | | def | business | name | business | uniqueconstdemo | UNIQUE | | def | business | PRIMARY | business | keydemo | PRIMARY KEY | | def | business | PRIMARY | business | nextiddemo | PRIMARY KEY | | def | business | PRIMARY | business | tablepri | PRIMARY KEY | | def | business | ConstFK | business | tabledemo2 | UNIQUE | | def | business | ConstFK | business | tabledemo3 | UNIQUE | | def | business | PRIMARY | business | college | PRIMARY KEY | | def | business | id | business | uniquedemo1 | UNIQUE | | def | business | id | business | uniqueautoid | UNIQUE | | def | business | PRIMARY | business | schemadatabasemethoddemo | PRIMARY KEY | | def | business | PRIMARY | business | employeeinformation | PRIMARY KEY | | def | business | name | business | addingunique | UNIQUE | | def | business | PRIMARY | business | parentdemo | PRIMARY KEY | | def | business | PRIMARY | business | lastinsertrecordiddemo | PRIMARY KEY | | def | business | PRIMARY | business | demoindex | PRIMARY KEY | | def | business | PRIMARY | business | compositeprimarykey | PRIMARY KEY | | def | business | PRIMARY | business | addingautoincrement | PRIMARY KEY | | def | business | Id | business | uniqueconstrainttable | UNIQUE | | def | business | PRIMARY | business | mergedemo1 | PRIMARY KEY | | def | business | PRIMARY | business | mergedemo2 | PRIMARY KEY | | def | business | PRIMARY | business | foreigntable1 | PRIMARY KEY | | def | business | PRIMARY | business | twoprimarykeytabledemo | PRIMARY KEY | | def | business | PRIMARY | business | showconstraintsdemo | PRIMARY KEY | | def | business | BookAuthor | business | showconstraintsdemo | UNIQUE | | def | business | PRIMARY | business | autoincrementtozero | PRIMARY KEY | | def | business | PRIMARY | business | altertabletoaddautoincrement | PRIMARY KEY | | def | business | PRIMARY | business | addingprimarykeydemo | PRIMARY KEY | | def | business | PRIMARY | business | resetprimarykey | PRIMARY KEY | | def | business | constFKPK | business | foreigntable | FOREIGN KEY | | def | business | FKConst | business | foreigntabledemo | FOREIGN KEY | | def | business | ConstFK | business | tblf | FOREIGN KEY | | def | business | StudCollegeConst | business | studentenrollment | FOREIGN KEY | | def | business | ConstChild | business | childdemo | FOREIGN KEY | | def | business | primarytable1demo_ibfk_1 | business | primarytable1demo | FOREIGN KEY | +--------------------+-------------------+--------------------------+--------------+------------------------------+-----------------+ 48 rows in set, 2 warnings (0.24 sec)>
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MySQL Workbenchを使用してサーバーからデータベースのERモデルを取得するにはどうすればよいですか?
サーバーからデータベースのERモデルを取得するには、最初にMySQLWorkbenchを起動する必要があります。スナップショットは次のとおりです- その後、「データベース」メニューを選択する必要があります- Database->Reverse Engineer その後、次のスクリーンショットのようにウィザードが開きます。パスワードを追加し、[OK]を2回押します。 [OK]ボタンを押した後、次のウィザードが表示されます。次のボタンを押す必要があります。次が表示されます- その後、上記のウィザードでマークしたように、「モデル」メニューを選択する必要があります
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Javaを使用してMySQLデータベースのテーブルから最後のレコードを取得しますか?
MySQLデータベースからデータを取得するには、JavaのexecuteQuery()メソッドを使用する必要があります。まず、MySQLデータベースにテーブルを作成します。ここでは、「サンプル」データベースに次のテーブルを作成します mysql> create table javaGetDataDemo - > ( - > Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, - > FirstName varchar(10), - > LastName varchar(10) - > ); Query OK, 0 rows