Table Management

When you create a database, the only tables in it are the system tables, which hold the database schema.

You may need to create, alter, and delete tables from a database. You can execute examples in documentation using dbisql, but the SQL statements are independent of the administration tool you are using.

You can create command files containing the CREATE TABLE and ALTER TABLE statements that define the tables in your database and store them in a source code control system. The command files allow you to re-create the database when necessary. They also let you create tables in a standardized way, which you can copy and revise.

• Guidelines for Creating Tables
  Create tables using Sybase Central or Interactive SQL.
• Guidelines for Altering Tables
  This section describes how to change the structure of a table using the ALTER TABLE statement.
• Guidelines for Dropping Tables
  The following DROP TABLE statement deletes all the records in the skill table and then removes the definition of the skill table from the database
• Creating Primary Keys
  Each row in a table is uniquely identified by its primary key.
• Creating Foreign Keys
  Each foreign key relationship relates a candidate key (primary key and unique constraint) in one column to a column in another table, which becomes the foreign key.
• Table Information in System Views
  Information about tables in a database is in the system view SYS.SYSTAB.