Editing Table Definitions 

Use

The 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 are in the Dictionary Perspective → Dictionary Explorer view of the SAP NetWeaver Developer Studio.

 

Activities

In the 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 the project and re-deploy the Java Dictionary archive.

●      Delete a table

To mark a table as deleted in the Java Dictionary, open the context menu of the table and choose Delete Table.

You cannot reuse the name of a deleted table if you work in the Java Development Infrastructure (JDI). For local development you are not allowed to reuse the name in the relevant Dictionary project only.

●      Add columns

To add a new column at the end of the column list, choose Add Column in the Table Editor.

To insert a new column before a selected one, choose Insert Column.

When adding columns to a table, the column order may change. Therefore, we recommend that you do not rely on field sequence when accessing a table.

●      Change the type of a column

This option is DBMS-specific. If the new JDBC type of the column is incompatible with the original type, this causes an error at deployment.

●      Increase the length, change the DB default value, and the description of a column

●      Create an index

For more information, see Creating Indexes.

●      Set table buffering

For more information, see Buffering Type.

 

You cannot perform the following activities:

●    Rename a table

●    Decrease the length of a field

●    Rename or delete a column – this leads to table conversion, which is not supported in the Java Dictionary yet