Text Join Vs Left Outer Join

[SibaP]

What is the difference between Left Outer Join Vs Text Join ?

I know Text Join is a language dependent but LOJ is not, apart from this, anything else ?

[michael_piesche]

In general: A Text Join clarifies and simplifies the join defintion (the resulting SQL join itself is technically a left outer join)

Further: There might be also checks on required cardinality for performance optimization as well as UI specific outputs, where the language is automatically set when performing the join but language is not returned in the resulting data set. It might also try to keep a developer from falsly choosing an INNER JOIN for joining text tables with value tables, if the join type Text Join was not an option, resulting in missing values when descriptions are not maintained.

So yes, you can do the same join with both join-types, but SAP has defined the Text Join for more specific tasks and requirements then the more general Left Outer Join.

See the SAP help for further information:

https://help.sap.com/viewer/3746eb56b77943b699df025ab2bc7552/Cloud/en-US/d5e6e175475f455f95c670bb148...

• Join Type: Text Join - This join type is used to obtain language-specific data from the text tables using a language column.

https://help.sap.com/viewer/3746eb56b77943b699df025ab2bc7552/Cloud/en-US/905d411f657b4ee693be695897a...

• A text join helps obtain language-specific data. It retrieves columns from a text table based on the session language of the user.
• When you execute a query, the engine evaluates the language setting of your connection. The texts are selected based on the language setting.

https://help.sap.com/viewer/3746eb56b77943b699df025ab2bc7552/Cloud/en-US/6100bb67b2e445329605a3b4650...

• Optimizing join columns is supported only for left outer joins with cardinality 1:1 or N:1, textjoins with cardinality 1:1 or N:1, right outer joins with cardinality 1:1 or 1:N, and referential joins.

https://help.sap.com/viewer/3746eb56b77943b699df025ab2bc7552/Cloud/en-US/72dab9b03d66485793a1afcb7f6...

• Join Properties: Language Column - The value of this property specifies the language column that the tool must use for executing text joins.

[SibaP]

Thanks Michael for your detailed explanation.I appreciate.

[michael_piesche]

siba.pkd21 , does this 'solve' your question or do you still have doubts? I assume you at least know when to use which? Let me know if there is more clarity necessary.

[venkateswaran_k]

Left Join

To get the information about orders to our customers table, regardless of whether a customer placed an order or not, we would use a left join. A left join returns all records from table A and any matching records from table B.

Important to note when use left join, make sure you put bigger table on left side (example customer)

Text Join

I do not know...

Inner Join

To get the information about orders to our customers table, only for the customer placed an order, we would use a inner join. A inner join returns only records from table A and matching records from table B