Editing Table Schema Data

Edit table schema to change the table definition and control the assigned privileges.

1. In Enterprise Explorer, expand the Tables folder and find the appropriate table.
2. Right-click the table, a table column, a primary key, or a constraint, and choose Edit.
3. Edit the table properties.
   Note: If you add or delete an index or a trigger, the operation is executed immediately on the data server. If you edit an index or trigger, or make additions or modifications or to other database objects, those changes are persisted to the data server when you save your changes in the editor.

   Tab	Description
   Columns	Set column properties for the table. Filter – use simple character matching and wildcards to display a subset of columns, then click Filter. For example, to display all columns that begin with a "c," enter c. To display all columns that begin with "au" and end in an "e," enter au*e. Table Name – specify the name of the table. Primary Key – make the corresponding column part of the primary key for this table. Column Name – specify the column name. Datatype – specify the column datatype. Nullable – enable null values for this column. Default – click ... to specify a default value for this column. Rule Binding – select a rule, if applicable, to restrict data in this column. This is an option for Adaptive Server Enterprise data servers only. Identity – mark this as an IDENTITY column, which is a column that contains system-generated values that uniquely identify each row in a table. This is an option for Adaptive Server Enterprise data servers only. Check Constraint – to define a check constraint for this column, click in the column, and click ... to open the Define Column Check Constraint wizard. This is an option for Adaptive Server Enterprise data servers only. IQ Unique – define the cardinality of the column. This is an option for Sybase IQ data servers only. Computed Column – for computed columns, enter an expression that defines the computation for the column. Comment – enter addtional comments about the column. This is an option for SQL Anywhere and Sybase IQ data servers only. Use Add and Delete to change the list of columns for this table.
   Constraints	Use Add and Delete to change the primary-key, unique, foreign-key, and check constraints for this table.
   Indexes	Use Add, Delete, and Edit to change the indexes defined for this table.
   Trigger (ASE and SQL Anywhere only)	Use Add, Delete, and Edit to change the triggers defined for this table.
   Permissions	Set permissions for the table. You can specify Granted, Granted with Grant Option, Inherited, and Revoked Inherited Permissions for one or all columns.
   Storage	Set storage properties for the table. Adaptive Server Enterprise: Segment – specify whether to create the index on a default or system segment. Max Row Per Page – specify the number of rows on data pages. Valid values are 0 – 256. The default is 0. Reserve Page Gap – specify the ratio of filled pages to empty pages to be left during I/O allocation operations. For each specified number of pages, an empty page is left for future expansion of the index. Valid values are 0 – 255. The default is 0. Identity Gap – specify the identity gap, which is the number IDs per block assigned in memory. For example, an identity gap of 10 indicates that ID numbers are allocated in memory in blocks of 10. If the server fails or is shut down with no wait, the maximum gap between the last ID number assigned to a row and the next ID number assigned to a row is 10 numbers of memory blocks assigned for each ID. Enter a value in the corresponding text field. The default is 0. Replacement Strategy – select Most Recently Used to replace items in cache with those that have been most recently used. Select Off to disable this option. Prefetch Strategy – select On to enable prefetching from cache. Select Off to disable this option. Locking Scheme: Specify the locking scheme for the table. Valid values are All Pages, All Rows, and Data Pages. Expected Row Size – if you have selected a locking scheme by data rows, specify the expected size of rows for this table. Sybase IQ: Free Size Reserved for Each Table – specify the default (200 bytes) or a percentage.
   DDL	View the DDL for the table. The content in this tab is read-only.

4. Select File > Save from the main WorkSpace menu.
5. Click Save in the Preview Changes window to execute the SQL code and save the changes to the database.

   The Preview Changes window appears unless the option is unselected through the Schema Object Editor Configuration preference page.