Lesson 1

A table is the basic logical structure in a database. All data in your Oracle database is stored in a table and understanding how to manage tables is one of the basic skills for a database administrator. This module will teach you to:

1. Create a table
2. Work with the basic Oracle datatypes
3. Create a table using the Schema Manager
4. Generate a list of the tables in your Oracle database
5. Gather information about the columns in a table
6. Modify a table by adding or modifying columns
7. Delete a table

The table is the basic building block of your Oracle database, and so the information in this chapter is indispensable for working with your database. A Schema Manager instance helps you with the abstraction of the generation of SQL assets such as Tables, Sequences, Foreign Keys and Indexes. You should consider a schema to be the user account and collection of all objects therein as a schema for all intents and purposes.
For example,
SCOTT is a schema that includes the EMP, DEPT and BONUS tables with various grants.
SYS is a schema that includes tables, views, grants, and additional components.
SYSTEM is a schema. Technically, a schema is the set of metadata (data dictionary) used by the database, typically generated using DDL. A schema defines attributes of the database, such as

1. tables,
2. columns, and
3. properties.

A database schema is a description of the data in a database.

In Oracle 19c, the traditional Oracle Enterprise Manager (OEM) Database Control, which included the Schema Manager, has been deprecated and is no longer available as it was in earlier versions of Oracle. For managing database objects like tables in Oracle 19c, DBAs and developers typically use Oracle SQL Developer or Oracle Enterprise Manager Cloud Control. Oracle SQL Developer is a free, integrated development environment that simplifies the management of Oracle Database in both traditional and Cloud deployments. It offers complete end-to-end development of your PL/SQL applications, a worksheet for running queries and scripts, a DBA console for managing the database, reports that you can customize, a complete data modeling solution, and much more. Oracle Enterprise Manager Cloud Control, on the other hand, is a more comprehensive tool designed for enterprise-level management of Oracle environments, offering deep insight and control over Oracle databases, middleware, hardware, and Oracle applications. To create a table in Oracle 19c using Oracle SQL Developer, you would typically:

1. Connect to your database using Oracle SQL Developer.
2. Navigate to your schema under the "Connections" pane.
3. Right-click on the "Tables" node and select "New Table" from the context menu.
4. Use the table creation GUI to define the table name, columns, data types, constraints, etc.
5. Execute the generated SQL script to create the table.

For database administration and schema management tasks that were previously handled by tools like Schema Manager in older versions, Oracle SQL Developer is the go-to tool in Oracle 19c environments.