topic Re: fields sequence in the select statement in Application Development and Automation Discussions

fields sequence in the select statement

Former Member — Tue, 18 Aug 2009 02:14:28 GMT

experts, help needed

itab has following fields,

vbeln posnr erdat erzet vkorg vtweg

kunnr posnr matnr bmeng status.

i have written like this

SELECT a_{vbeln a}erdat a_{erzet a}vkorg a~vtweg

a_{kunnr b}posnr b~matnr

FROM vbak AS a INNER JOIN vbap AS b

ON a_{vbeln = b}vbeln

INTO TABLE itab1

FOR ALL ENTRIES IN itab

WHERE a~vbeln = itab-vbeln.

endif.

but my internal table fields sequence are different. so i changed the posnr field in the select query to the second place.

SELECT a_{vbeln b}posnr a_{erdat a}erzet a_{vkorg a}vtweg

a_{kunnr b}matnr

FROM vbak AS a INNER JOIN vbap AS b

ON a_{vbeln = b}vbeln

INTO TABLE itab1

FOR ALL ENTRIES IN itab

WHERE a~vbeln = itab-vbeln.

endif.

so in above two select statements which one is right , according to coding standards,?

in this case do i need to use the into corresponding fields addition because i am not selecting bmeng , status fields into the itab?

Re: fields sequence in the select statement

SG141 — Tue, 18 Aug 2009 02:31:30 GMT

Hi,

Change the field sequence in the internal table as per the first select query. I don't think there will be any performance/ run time difference between first and second select statements. Also, avoid using corresponding fields addition as it a performance killer.

Re: fields sequence in the select statement

daixiong_jiang3 — Tue, 18 Aug 2009 02:36:38 GMT

The second one is right and can have a better performance.

Re: fields sequence in the select statement

Former Member — Tue, 18 Aug 2009 02:41:32 GMT

thank you for the answers.

my internal table has the fields in this sequence

itab :-

vbeln

posnr

erdat

erzet

vkorg

vtweg

kunnr

matnr

bmeng

status.

1)so which select query i need to use in the above for this sequence either first or second, if so why not other

2) do i need to use the into corresponding fields addition because i am not using the fields bmeng and status and also in the first query the posnr in not in sequence to itab

Re: fields sequence in the select statement

awin_prabhu — Tue, 18 Aug 2009 03:58:04 GMT

Hi,

1. Use second query because select statement will always fill internal table in a sequence order in which fields have been declared.

2. For second query u do not need to use 'INTO CORRESPONDING FIELDS OF' because the field names in select query is in same sequence with internal table fields. Since 'bmeng' and 'status' fields is at the end it will affect the sequence.

'INTO CORRESPONDING FIELDS OF' is only used when sequence of field names in select query and internal table declaration differs. Otherwise type and length mismatch of fields will occur.

Re: fields sequence in the select statement

Former Member — Tue, 18 Aug 2009 04:04:33 GMT

Hi,

Of the two select statements,


SELECT a~vbeln b~posnr a~erdat a~erzet a~vkorg a~vtweg
a~kunnr b~matnr 
FROM vbak AS a INNER JOIN vbap AS b
ON a~vbeln = b~vbeln
INTO TABLE itab1
FOR ALL ENTRIES IN itab
WHERE a~vbeln = itab-vbeln.

is the better one. I,e specifyiig the field sequence exactly as you have in the internal table. Even according to standards, this is better.

If you are chaning the sequence of select fields, then you have to use the INTO CORRESPONDING FILEDS OF TABLE addition, so that the system itself finds the relevant order of fields and fill them automatically.

This is a additional work which has to be performed by the compiler.

Thus its better to use INTO CORRESPONDING FILEDS OF TABLE only when you are using select * , or when you are not sure of the field sequence inthe table.

Regards,

Vik

Re: fields sequence in the select statement

Former Member — Tue, 18 Aug 2009 04:09:19 GMT

Hi,

This will be good select query in accordance with performance and standard.

if not itab[] is initial.

SELECT a_{vbeln b}posnr a_{erdat a}erzet

a_{vkorg a}vtweg a_{kunnr b}matnr

FROM vbak AS a INNER JOIN vbap AS b

ON a_{vbeln = b}vbeln

INTO TABLE itab1

FOR ALL ENTRIES IN itab

WHERE a~vbeln = itab-vbeln.

endif.

Regards,

Vijay

Re: fields sequence in the select statement

Former Member — Tue, 18 Aug 2009 05:21:24 GMT

Hello,

You should always follow ABAP standard while coding. Select query should have all the fields in sequence as per the order defined in the database table. This will definetly help indexes to improve performance.

Hope this helps!

Thanks,

Augustin.