apache derby schemas

In Apache Derby, a schema is a named container for database objects such as tables, indexes, and procedures. Schemas can be used to organize database objects into logical groups, and to control access to those objects by different users or applications.

Here is the basic syntax for creating a schema in Apache Derby:

CREATE SCHEMA schema_name AUTHORIZATION user_name

In this syntax, schema_name is the name of the schema, and user_name is the name of the user who will own the schema. Once a schema is created, you can create tables, indexes, and other objects within that schema using the CREATE TABLE, CREATE INDEX, and other statements.

Here is an example of creating a schema in Apache Derby:

CREATE SCHEMA sales AUTHORIZATION salesperson;

In this example, a schema named sales is created with salesperson as the owner. Once the schema is created, tables and other objects can be created within the sales schema.

To use a table or other object in a schema, you can prefix the object name with the schema name and a dot (.) separator. For example, to select data from a table named orders in the sales schema, you can use the following SQL statement:

SELECT * FROM sales.orders;

In addition to organizing database objects, schemas can also be used to control access to those objects by different users or applications. For example, you can grant or revoke permissions on a schema or on individual objects within a schema using the GRANT and REVOKE statements.

Schemas can be a powerful tool for organizing and securing database objects in Apache Derby. However, it's important to carefully consider the design of your schema hierarchy and to properly secure your schemas to prevent unauthorized access to sensitive data.