topic Re: joins in Application Development and Automation Discussions

joins

Former Member — Fri, 15 Sep 2006 05:56:37 GMT

Hi frenz,

Can i use join on cluster table and transparent tables..if so what is the effect?

regards,

anil..

Re: joins

hymavathi_oruganti — Fri, 15 Sep 2006 05:58:28 GMT

u can never use joins on cluster tables.

joins can be used on transparent tables.

if any one table in join is cluster table, u will get error message.

Re: joins

Former Member — Fri, 15 Sep 2006 05:59:14 GMT

clusters also we cant write join

Re: joins

Former Member — Fri, 15 Sep 2006 06:00:32 GMT

can u give more clear information..

Re: joins

Former Member — Fri, 15 Sep 2006 06:08:48 GMT

Hi,

You can put joins only with transparent tables. This featur of joins is not available for cluster table. Because, only in tranparent tables, all business data and commercial data are stored.

Where as Cluster tables contain continuous text, for example, documentation. Several cluster tables can be combined to form a table cluster. Several logical lines of different tables are combined to form a physical record in this table type. This permits object-by-object storage or object-by-object access. In order to combine tables in clusters, at least parts of the keys must agree. Several cluster tables are stored in one corresponding table on the database.

So these tables are used for internal purposes i.e. with in the company, where as transparent data is used for external purposes.

P.S.mark all helpful answers for points.

JLN

Re: joins

abdul_hakim — Fri, 15 Sep 2006 06:23:43 GMT

you cannot use joins on cluster tables.

Cheers,

Abdul Hakim

Re: joins

Former Member — Fri, 15 Sep 2006 06:41:12 GMT

Hi Anil,

you cannot use joins on clustered tables ...

This is taken from F1 help of inner join.

Effect

Selects data from the transparent database tables or views specified in tabref1 and tabref2. tabref1 and tabref2 either have the same form as in variant 1 or are themseleves joine expressions. The key word INNER can be omitted. The database tables or views specified in tabref1 and tabref2 must be recognized in the ABAP-Dictionary.

In a relational data structure, it is quite normal for data that belongs together to be split up across several tables to help standardization (see relational database). To regroup this information in a database query, you can link tables using a join command. This formulates conditions for the columns of the tables involved. An inner join contains all combinations of lines from database table tabref1 with lines from database table tabref2 that meet the condition specified in the logical condition ON cond.

For outer join:

... FROM tabref1 LEFT [OUTER] JOIN tabref2 ON cond

Effect

Selects data from the transparent database tables or views specified in tabref1 and tabref2. tabref1 and tabref2 either have the same form as in variant 1 or are themseleves joine expressions. The key word OUTER can be omitted. The database tables or views specified in tabref1 and tabref2 must be recognized in the ABAP Dictionary and declared in the program with an appropriate TABLES statement.

In order to determine the result of a SELECT statement where the FROM clause contains a left outer join, the database system creates a temporary table containing the lines that meet the ON condition. The remaining fields from the left hand table (tabref1) are then added to this table, and their corresponding fields from the right hand table are filled with NULL values. The system then applies the WHERE condition to the table

Regards,

Santosh