Introducing SQL Anywhere Studio
   Tutorial: Managing Databases with Sybase Central
    Lesson 2: Create and edit tables

Edit the Office table

This section describes how to edit an existing table. The steps show you how to add a primary key to the table created in the previous section by turning a column named office_id into a primary key.

Edit the Office table

1. Open the Tables folder and select the office table.

2. Give the first row the name of office_id, and assign a data type of small int.

   The checkmark in the PKey column indicates that the column named office_id is the primary key for the table.

   Primary key conditions  If a checkmark appears in the Nulls column, or if duplicate values are stored in the office_id column, the column cannot be changed to a primary key.

3. On the toolbar, click Save Table.

4. On the toolbar, click Add Column.

5. Edit the new column so that its name is office_name, its type is char, and its size is 20. Select Nulls so that office_name is allowed to be blank.

6. Click Save Table.

The column is now in the database, although it contains no data.

Notes 

• Most objects in Sybase Central have property sheets, including tables, users, and stored procedures.

• When you click on many of the folders, New item buttons appear in the toolbar. Clicking these buttons creates new objects for the database.

• Whenever you select an object in Sybase Central, commands related to that object appear in several places: in the File menu, in a popup menu that you can access by right-clicking the object, and as buttons on the toolbar.

• Once you open a container, its contents are cached to improve performance. You can access two refresh commands in the View menu to update the view of either the current container or the entire window.