topic Re: Data Dictionary - Primery Key in Application Development and Automation Discussions

Data Dictionary - Primery Key

Former Member — Fri, 14 Mar 2008 06:54:30 GMT

What will be the Maximum numbers of Primary key, which we can assign in z table.

Re: Data Dictionary - Primery Key

Former Member — Fri, 14 Mar 2008 07:03:55 GMT

For some applications, it is useful to uniquely identify the rows in a table by one or more columns so that you can process them in a specified sequence, for example. You can do this by assigning a “primary key.” The column names that are to create the table key are represented by the keywords PRIMARY KEY. The input values of the key columns defined in this way must not be a NULL value.

You can use the primary key to insert rows in a table in the same way as you insert rows in a base table when no primary key is defined. However, the system outputs an error message if you attempt to insert an existing value into the primary key column a second time, since the uniqueness of the column is ensured by defining the primary key.

*A primary key can consist of multiple columns. However, it is unusual for a key to be constructed from more than five columns, since this makes it difficult for users to enter unique values. The arrangement of the columns behind the keywords PRIMARY KEY defines the key sequence.*

Re: Data Dictionary - Primery Key

Former Member — Fri, 14 Mar 2008 07:18:41 GMT

Hi Anshuman,

Check with the following link

http://www.sapdb.org/7.4/sap_db_features.htm

reward if helpful.

Regds,

Mandeep

Re: Data Dictionary - Primery Key

Former Member — Fri, 14 Mar 2008 09:20:18 GMT

Hi,

This is one of the good questions,

You can create up to 16 primary key for one table.

if you have any idea about BW then you can easily understand the scenario.In BW data is stored in cube.

For a single cube there are 16 dimensions tables are there.

These dimension tables works based on primary keys in FACT table.

The maximum limit is 16 in any transperant table.

Regards,

swami.