Comments
ABAP INTO CLAUSE Statement syntax, information and example SAP source code
SELECT - INTO
Short Reference
ABAP Syntax ... { INTO
{ {[CORRESPONDING FIELDS OF] wa}|(dobj1, dobj2, ...)} }
| { INTO|APPENDING
[CORRESPONDING FIELDS OF] TABLE itab [PACKAGE SIZE n] }
[ creating ] ... .
ABAP_ALTERNATIVES:
1 ... INTO [CORRESPONDING FIELDS OF] wa
2 ... INTO (dobj1, dobj2, ... )
3
What does it do? target specifies to which data objects the result set of a SELECT or FETCH statement is assigned. Either a single work area wa or a list of data objects dobj1, dobj2, ... can be specified after INTO , or an internal table itab can be specified after INTO or APPENDING .
If a LOB of the result set is associated with a LOB handle in the target
, it may be necessary to use creating
to specify whether a data stream or a
locator is being used.
Latest notes: When specifying the data objects, there are no dynamic variants that correspond to the other additions. Instead, dynamically created data objects can be used (see the example for CREATE DATA ).
Whether data should better be read into an internal table or a work area depends on the type of further processing: If data is required only once in a program, it should be imported into a work area, row by row, by a SELECT . Reading data into an internal table requires more memory space (without the disadvantage) because of a considerably higher reading speed. If, on the other hand, data is required many times in a program, it should be read into an internal table. The disadvantage of the increased memory requirement is more than compensated for here by the advantage of a once-only selection.
If data is to be imported into an internal table, it is better to import it once into an internal table than to put it, row by row, into a work area and then finally add it to an internal table using APPEND .
The variants with the addition INTO CORRESPONDING FIELDS require a greater runtime than the corresponding variants without
CORRESPONDING FIELDS , however the runtime is less dependent on the volume.
The variants with the addition INTO CORRESPONDING FIELDS run the risk of having target areas with more components than are actually filled. This should only be the case if the components that are not filled are then filled in the program. Otherwise appropriately sized work areas should be used to avoid a large amount of memory being filled by initial values (especially in internal tables).
The statement SELECT also has an obsolete short form , in which INTO or
APPENDING can be omitted.
Reference variables for LOB handle s or LOB handle structures cannot currently be specified after the statement
.
ABAP_ALTERNATIVE_1 ... INTO [CORRESPONDING FIELDS OF] wa
What does it do? For wa , a data object can be specified that must meet certain prerequisites without
CORRESPONDING FIELDS OF being specified. If the result set consists of a single row, this row is assigned to wa . If the result set has multiple rows, SELECT must be followed by an ENDSELECT
statement; the result set is assigned to the work area wa row-by-row and can be evaluated in the loop. After ENDSELECT , the work area wa contains the row that was assigned last. If used in the FETCH statement, a row is extracted at the current cursor position. If the result is empty, the work area remains unchanged.
The rows of the result set are assigned as follows, based on the columns specified after SELECT :
* specified without the addition CORRESPONDING FIELDS
If all columns are read using * and CORRESPONDING FIELDS
is not specified, SELECT behaves as follows:
When specifying a work area that does not contain any reference variables for LOB handle s , the row is assigned to the result set left-aligned and unconverted in accordance with the structure of the result set. Unaffected parts of wa retain their previous content. To be able to access the components of the result set according to type, the work area wa must be structured like the result set.
If a LOB handle structure
is specified, it must be constructed (in accordance with the prerequisites ) exactly like the structure of the database table. The contents of the columns of the result set that are not assigned to any LOB handle components are directly assigned to the corresponding components of the work area. A LOB handle
is created for each LOB handle component .
All other combinations
If the result set consists of a single column specified explicitly after SELECT or a single
aggregate expression , then wa can be an elementary data object or a structure. If the result set consists of multiple columns, it must be a structure and the following rules apply:
If the CORRESPONDING FIELDS addition is not specified, wa
must contain enough components and the contents of the columns are assigned to the components of wa from left to right in the order specified after SELECT .
If the CORRESPONDING FIELDS addition is specified, only those contents of columns for which there are identically named components in wa are assigned to them. This respects the alternative column names. Columns and aggregate expressions that appear multiple times can only be assigned using alternative column names, if
ned.
Assignment rules apply to the individual assignments. If a LOB of a reference variable for LOB handle is assigned, a LOB handle is created .
Latest notes: The addition CORRESPONDING FIELDS ignores names which were only defined using the addition AS name of the statement INCLUDE or when integrating the structures in ABAP Dictionary. However, components that were renamed using the RENAMING WITH SUFFIX addition of the INCLUDE statement or similarly in ABAP Dictionary are not ignored.
The addition CORRESPONDING FIELDS determines the assignment of the fields of the same name once for each SELECT statement at runtime.
Example ABAP Coding In this example, four columns of the result set are read into four correspondingly named components of a work area.
DATA wa TYPE spfli.
SELECT carrid connid cityfrom cityto
FROM spfli
INTO CORRESPONDING FIELDS OF wa.
cl_demo_output=>write_data( wa ).
ENDSELECT.
cl_demo_output=>display( ).
ABAP_ALTERNATIVE_2 ... INTO (dobj1, dobj2, ... )
What does it do? If the result set consists of multiple columns or aggregate expressions specified explicitly after SELECT , a list of elementary data objects dobj1, dobj2, ... (in parentheses and separated by commas) can be specified after INTO . The same number of elementary data objects dobj must be specified as there are columns in the result set. The contents of the columns in the result set are assigned to the data objects from left to right, according to the order specified after SELECT .
Assignment rules apply to the individual assignments. If a LOB of a reference variable for LOB handle is assigned, a LOB handle is created . If the result set is empty, the data objects remain unchanged.
If the result set consists of one row, the columns are assigned from that row. If the result set contains multiple rows, SELECT must be followed by an ENDSELECT statement; the columns of the result set are assigned to the data objects row-by-row and they can be evaluated in a loop. If used in the FETCH statement, the columns of the row are extracted at the current cursor position.
Example ABAP Coding In this example, four columns of the result set are read into four individually specified columns of a structure. Unlike in the previous example, the runtime environment does not compare names here.
DATA wa TYPE spfli.
SELECT carrid connid cityfrom cityto
FROM spfli
INTO (wa-carrid, wa-connid, wa-cityfrom, wa-cityto).
cl_demo_output=>write_data( wa ).
ENDSELECT.
cl_demo_output=>display( ).
ABAP_ALTERNATIVE_3
ABAP_ADDITION:
... PACKAGE SIZE n
What does it do? If the result set consists of multiple rows, an internal table itab of any table type can be specified after INTO or APPENDING . The row type of the internal table must meet the prerequisites .
The result set is inserted into the internal table itab row-by-row; a sorting process is executed in the case of a sorted table . If INTO is used, the internal table is initialized. Previous rows remain intact if
APPENDING is used.
Before any assignment of a row of the result set, an initial row of the internal table itab is created and the row of the result set is assigned to this row. When assigning a row of the result set to a row of the internal table with or without CORRESPONDING FIELDS , the same rules apply as when assigning to an individual work area wa (see above) with the exception that when inserting into internal tables,
LOB handle s can be created as
locators but not as read streams
.
If the PACKAGE SIZE addition is not used, all rows of the result set are inserted in the internal table itab and the
ENDSELECT statement must not be specified after SELECT .
If the result set is empty, the internal table is initialized when INTO is used, and remains unchanged when APPENDING is used.
Latest notes: When specifying an internal table with a unique primary or secondary table key , an exception is raised that cannot be handled if an attempt is made to create a duplicate entry.
If the internal table contains more columns than required when using the addition CORRESPONDING FIELDS , then generally too much memory is being used by initial fields and a warning is displayed by the syntax check. In cases where the columns are needed, for example when they are filled with derived values by the program, a pragma can be used to suppress the warning.
Since the maximum number of data streams
that can be assigned to an Open SQL statement is limited to 16, it does not make any sense to create read streams when importing internal tables.
ABAP_ADDITION ... PACKAGE SIZE n
What does it do? If the addition PACKAGE SIZE is specified, all rows of the result set for SELECT are processed in a loop, which must be closed with ENDSELECT . They are inserted in packages of n rows in the internal table itab . n expects a data object of type i that contains the number of rows. If the value of n is less than 0, an exception is raised that cannot be handled. If n is equal to 0, all rows of the result set are inserted in the internal table itab . If used in the FETCH statement, n rows are extracted from the current cursor position.
If INTO is used, the internal table is initialized before each insertion and, in the SELECT loop, it only contains the rows of the current package. If APPENDING is used, a further package is added to the existing rows of the internal table for each SELECT loop or for each extraction using FETCH .
After ENDSELECT , the content of itab is not defined if INTO is used. That is, the table can either contain the rows of the last package or it can be initial. If APPENDING is used, the content of itab retains the state of the last loop pass.
Latest notes: The addition PACKAGE SIZE can be used after
INTO to limit the amount of data read in one go. Otherwise a runtime error can occur when reading a data set that is too large into an i
nternal table so that its maximum size is exceeded. PACKAGE SIZE cannot prevent this runtime error after
APPENDING .
If the addition PACKAGE SIZE is specified with the addition FOR ALL ENTRIES , all selected rows are read initially into an internal system table and the packages are only created when they are passed from the system table to the actual target table. The addition FOR ALL ENTRIES thereby negates the effect of PACKAGE SIZE in preventing memory overflow.
The addition PACKAGE SIZE does not influence the size of the packages (configured in the profile parameters) used to transport data between the database server and the application server.
Example ABAP Coding In this example, all columns of a result set are read into an internal table, the row type of which is a nested structure with the same structure as the result set. Note that in practice, the column carrid exists twice in the result set with the same content and, after the assignment, this content is stored redundantly in the columns struc1-carrid and struc2-carrid of the internal table.
DATA: BEGIN OF wa,
struc1 TYPE scarr,
struc2 TYPE spfli,
END OF wa.
DATA itab LIKE SORTED TABLE OF wa
WITH UNIQUE KEY table_line.
DATA: BEGIN OF output_wa,
carrid LIKE wa-struc1-carrid,
carrname LIKE wa-struc1-carrname,
connid LIKE wa-struc2-connid,
END OF output_wa,
output LIKE TABLE OF output_wa WITH EMPTY KEY.
SELECT *
FROM scarr
INNER JOIN spfli ON scarr~carrid = spfli~carrid
INTO TABLE itab.
LOOP AT itab INTO wa.
output_wa-carrid = wa-struc1-carrid.
output_wa-carrname = wa-struc1-carrname.
output_wa-connid = wa-struc2-connid.
APPEND output_wa TO output.
ENDLOOP.
cl_demo_output=>display_data( output ).
Documentation extract taken from SAP system, � Copyright SAP AG. All rights reserved
