Doubt about Select statement.

Question

Hi folks!!
             I have a few doubts about the select statements, it may be a silly things but its useful for me.
what is   difference between below statment.
1)SELECT * FROM TABLE.
2)SELECT SINGLE * FROM TABLE
3)SELECT SINGLE FROM TABLE.
Hope i will get answer,thanks in advance.
Regards
Richie..

Answer 1

Hi,
try this and if possible use sap help.i mean place the cursor on select and press F1.
             Types of select statements:
1.     select * from ztxlfa1 into table it.
             This is simple select statement to fetch all the data of db table into internal table it.
   2.   select * from ztxlfa1 into table it where lifnr between 'V2' and 'V5'.
        Thisis using where condition between v2 and v5.
  4. select * from ztxlfa1 where land1 = 'DE'. "row goes into default table work Area
  5. select lifnr land1 from ztxlfa1
        into corresponding fields of it   "notice 'table' is omitted
         where land1 = 'DE'.
          append it.
           endselect.
     Now data will go into work area. and then u will add it to internal table by     
        append statement.
  6.   Table 13.2 contains a list of the various forms of select as it is used with internal tables and their relative efficiency. They are in descending order of most-to-least efficient.
Table 13.2  Various Forms of SELECT when Filling an Internal Table
Statement(s)                                   Writes To
select into table it                                    Body
select into corresponding fields of table it   Body
select into it                                    Header line
select into corresponding fields of it           Header line
7. SELECT VBRK~VBELN
       VBRK~VKORG
       VBRK~FKDAT
       VBRK~NETWR
       VBRK~WAERK
       TVKOT~VTEXT
       T001~BUKRS
       T001~BUTXT
    INTO CORRESPONDING FIELDS OF TABLE IT_FINAL
    FROM VBRK
    INNER JOIN TVKOT ON VBRKVKORG = TVKOTVKORG
    INNER JOIN T001 ON VBRKBUKRS = T001BUKRS
    WHERE VBELN IN DOCNUM AND VBRK~FKSTO = ''
   AND VBRK~FKDAT in date.
Select statement using inner joins for vbrk and t001 and tvkot table for this case based on the conditions
8. SELECT T001W~NAME1 INTO  TABLE IT1_T001W
FROM T001W INNER JOIN EKPO ON T001WWERKS = EKPOWERKS
WHERE EKPO~EBELN = PURORD.
here selecting a single field into table it1_t001winner join on ekpo.
9. SELECT BUKRS LIFNR EBELN FROM EKKO INTO CORRESPONDING FIELDS OF IT_EKKO WHERE     EBELN IN P_O_NO.
ENDSELECT.
SELECT BUTXT   FROM T001 INTO  IT_T001 FOR ALL ENTRIES IN IT_EKKO WHERE BUKRS = IT_EKKO-BUKRS.
ENDSELECT.
APPEND IT_T001.
here I am using for all entries statement with select statement. Both joins and for all entries used to fetch the data on condition but for all entries is the best one.
10. SELECT AVBELN BVTEXT AFKDAT CBUTXT ANETWR AWAERK INTO TABLE ITAB
             FROM  VBRK AS A
             INNER JOIN TVKOT AS B ON
             AVKORG EQ BVKORG
             INNER JOIN T001 AS C ON
             ABUKRS EQ CBUKRS
             WHERE  AVBELN IN BDOCU AND AFKSTO EQ ' ' AND B~SPRAS EQ
             SY-LANGU
             AND AFKDAT IN BDATE AND AVBELN EQ ANY ( SELECT VBELN FROM
            VBRP WHERE VBRP~MATNR EQ ITEMS ).
    Here we are using sub query in inner join specified in brackets.
Thanks,
chandu.