Editing Table Definitions

Use

Java Dictionary enables you to modify the definitions of tables that have been deployed to the database already. However, there are certain requirements and limitations that are introduced to prevent data loss and runtime problems when accessing the modified tables.

Prerequisites

You have:

Opened the Dictionary perspective in the SAP NetWeaver Developer Studio
Expanded the nodes of the Dictionary development component that contains your database tables definitions
Opened a table for editing

Procedure

In Java Dictionary, you can perform the following modifications on tables that already exist in the database schema. All changes are applied to the tables in the database after you rebuild and redeploy the relevant Dictionary development component (DC).

For more information, see Deploying Dictionary Development Components .

Deleting Tables

In the context menu of the table in the Dictionary Explorer , choose Delete .

Adding Columns to Tables

To add a new column at the end of the column list, choose Add Column in the context menu of the table editor.
To insert a new column before a selected one, choose Insert Column in the context menu of the selected column.

Complete the required fields, then choose Finish .

Changing Column Parameters

You can change the following column parameters: type of a column, length, DB default value, description.

In the table editor, select the column and choose Edit Column in the context menu.
Change the relevant parameters, then choose Finish .

Note

Changing the type of a column is a DBMS-specific option. If the new JDBC type of the column is incompatible with the original type, this may lead to a table conversion. A table conversion contains a data copy and therefore is a time-consuming operation. You should perform this change only if it is absolutely necessary.

Caution

Decreasing the length of a column or deleting a new column can lead to a table conversion. A table conversion contains a data copy and can therefore need a lot of time (especially during deployment in the customer system during upgrade, if the table already contains data there). You should make the change only if it is really necessary.

Renaming a column is equivalent to dropping a column and creating a similar column with a new name. This operation leads to a loss of data of the content of the old column. The content of the new column is empty.

Creating Table Indexes

For more information, see Creating Indexes .

Enabling Table Buffering

For more information, see Buffer Granularity .

More Information

Creating Tables