topic Re: select single and select in Application Development and Automation Discussions

select single and select

Former Member — Tue, 22 Aug 2006 18:33:55 GMT

hi everybody

what is the exact difference between select single vbeln and select vbeln

In what situations i should use these select single vbeln or select vbeln

regards

hridhayanjili.

Re: select single and select

abdul_hakim — Tue, 22 Aug 2006 18:40:14 GMT

select single is for fetching single record from the database based on the unique keys.

select <field name> is used for selecting a particular field from a table.here your select clause may fetch multiple records but select single will fetch only one record.

i would advice you to read the OPEN SQL document under

http://help.sap.com

Cheers,

Abdul Hakim

mark all useful answers..

Re: select single and select

Former Member — Tue, 22 Aug 2006 18:51:57 GMT

"select single vbeln" will extract one and only one sales order number from the DB (based on the conditions in the WHERE clause).

"select vbeln" requires the addition of ENDSELECT and creates a 'selection loop'. This loop will select ALL sales order numbers from the DB (based on the conditions in the WHERE clause).

If you KNOW that need one and only record, SELECT SINGLE is faster of the two... it makes only one trip to the DB. The SELECT... ENDSELECT must make multiple trips to the DB... even if only 1 record exists... this method must make 2 trips to the DB to complete it's execution.

Re: select single and select

Former Member — Tue, 22 Aug 2006 19:05:52 GMT

Hrid,

Have your questions been answered? If so, please reward points accordingly and close the thread.

If not, provide more details of your question(s).

Thanks in advance.

Re: select single and select

Former Member — Tue, 22 Aug 2006 19:08:38 GMT

Hai

Go through the following Document

According to SAP Performance course the SELECT UP TO 1 ROWS is faster than SELECT SINGLE because you are not

using all the primary key fields.

select single is a construct designed to read database records with primary key. In the absence of the primary key,

it might end up doing a sequential search, whereas the select up to 1 rows may assume that there is no primary key

supplied and will try to find most suitable index.

The best way to find out is through sql trace or runtime analysis.

Use "select up to 1 rows" only if you are sure that all the records returned will have the same value for the field(s)

you are interested in. If not, you will be reading only the first record which matches the criteria, but may be the

second or the third record has the value you are looking for.

The System test result showed that the variant Single * takes less time than Up to 1 rows as there is an additional

level for COUNT STOP KEY for SELECT ENDSELECT UP TO 1 ROWS.

The 'SELECT SINGLE' statement selects the first row in the database that it finds that fulfils the 'WHERE' clause

If this results in multiple records then only the first one will be returned and therefore may not be unique.

Mainly: to read data from

The 'SELECT .... UP TO 1 ROWS' statement is subtly different. The database selects all of the relevant records that

are defined by the WHERE clause, applies any aggregate, ordering or grouping functions to them and then returns

the first record of the result set.

Mainly: to check if entries exist.

You can refer to the below link..

http://www.sap-img.com/abap/difference-between-select-single-and-select-upto-one-rows.htm

Regards

Sreeni