Create a database

This topic describes the requirements and examples for creating a database.

About databases

In MySQL mode of OceanBase Database, a database is a collection of database objects. After you connect to a MySQL tenant of OceanBase Database, you can create a database in the MySQL tenant to store and manage its data.

Preparations

Before you create a database, make sure that:

• You have logged on to a MySQL tenant of OceanBase Database. For more information about how to connect to OceanBase Database, see Connect to OceanBase Database.

  Note

  You can query the oceanbase.DBA_OB_TENANTS view in the sys tenant to confirm the mode of the tenant to which you have logged on.

• You have the CREATE privilege. For more information about how to view your privileges, see View user privileges. If you do not have the required privileges, contact the administrator. For more information, see Modify user privileges.

Create a database

Use the CREATE DATABASE statement to create a database. Then, complete the creation of the database based on the suggestions and examples in this topic.

Suggestions on database creation

• Do not directly use the default database in the system. We recommend that you use an SQL statement to create your own database.

• In OceanBase Database, the name of each database must be globally unique.

• Do not use reserved keywords as the database name. For more information about the reserved keywords in OceanBase Database in MySQL mode, see Reserved keywords.

• To adapt to long-term business development, the character set of the database must be able to store most characters. We recommend that you use the UTF8 character set when you create a database. For more information about the character sets supported by OceanBase Database, see Database-level character sets.

Examples

Create a database and specify its character set

Create a database named test2 and specify the character set to UTF8.

obclient [test]> CREATE DATABASE test2 DEFAULT CHARACTER SET UTF8;
Query OK, 1 row affected

obclient [test]> SHOW CREATE DATABASE test2;
+----------+-------------------------------------------------------------------------+
| Database | Create Database                                                         |
+----------+-------------------------------------------------------------------------+
| test2    | CREATE DATABASE `test2` DEFAULT CHARACTER SET = utf8mb4 REPLICA_NUM = 1 |
+----------+-------------------------------------------------------------------------+
1 row in set

Create a database that supports read and write operations

Create a database named test3 that supports read and write operations.

obclient [test]> CREATE DATABASE test3 READ WRITE;
Query OK, 1 row affected

obclient [mwx]> SHOW CREATE DATABASE test3;
+----------+-------------------------------------------------------------------------+
| Database | Create Database                                                         |
+----------+-------------------------------------------------------------------------+
| test3    | CREATE DATABASE `test3` DEFAULT CHARACTER SET = utf8mb4 REPLICA_NUM = 1 |
+----------+-------------------------------------------------------------------------+
1 row in set

Create a read-only database

Create a read-only database named test4.

obclient [test]> CREATE DATABASE test4 READ ONLY;
Query OK, 1 row affected

obclient [test]> SHOW CREATE DATABASE test4;
+----------+-----------------------------------------------------------------------------------+
| Database | Create Database                                                                   |
+----------+-----------------------------------------------------------------------------------+
| test4    | CREATE DATABASE `test4` DEFAULT CHARACTER SET = utf8mb4 REPLICA_NUM = 1 READ ONLY |
+----------+-----------------------------------------------------------------------------------+
1 row in set

More information

• Create a table