ABAP Keyword Documentation → ABAP - Reference → Processing Internal Data → Internal Tables → Processing Statements for Internal Tables → MODIFY itab
MODIFY itab - itab_lines
Other versions: 7.31 | 7.40 | 7.54
Syntax
... itab FROM wa [USING KEY keyname]
TRANSPORTING
comp1
comp2 ... WHERE log_exp|(cond_syntax).
Extras
1. ... USING KEY keyname
2. ... WHERE log_exp
3. ... WHERE (cond_syntax)
Effect
In this variant, the statement MODIFY
assigns the content of the components
comp1 comp2 ...
of the work area wa
specified
after TRANSPORTING
to all rows of the table itab
that meet the condition after WHERE
. wa
is a
functional operand position. The work area wa
must be
compatible with the row type of the internal table.
The addition TRANSPORTING
has the same effect as
changing individual rows. The addition WHERE
can only be specified together with the addition TRANSPORTING
.
Note
Outside of classes, an obsolete short form is possible where FROM wa
can be omitted if the internal table has a
header line itab
with the same name. The statement then uses the header line as the work area implicitly. Furthermore, USING KEY
cannot be specified without USING KEY
.
Example
Takes the content of the component planetype
for all rows in the internal
table sflight_tab
where this component contains the value p_plane1
and changes it to the value p_plane2
.
PARAMETERS: p_carrid TYPE sflight-carrid,
p_connid TYPE sflight-connid,
p_plane1 TYPE sflight-planetype,
p_plane2 TYPE sflight-planetype.
DATA sflight_tab TYPE SORTED TABLE OF sflight
WITH UNIQUE KEY carrid connid fldate.
DATA sflight_wa TYPE sflight.
SELECT *
FROM sflight
WHERE carrid = @p_carrid AND
connid = @p_connid
INTO TABLE @sflight_tab.
sflight_wa-planetype = p_plane2.
MODIFY sflight_tab FROM sflight_wa
TRANSPORTING planetype WHERE planetype = p_plane1.
Addition 1
... USING KEY keyname
Effect
The USING KEY
addition can be used to specify a table key in
keyname
used to carry out the processing. The specified table key influences the order in which the table rows are accessed, and the evaluation of the remaining conditions.
If the primary table key is specified, the processing behaves in the same way as when no key is explicitly specified. If a secondary table key is specified, the order in which the rows are accessed is as follows:
-
Sorted key specified
The rows are processed by ascending row number in the secondary table index -
Hash key specified
The rows are processed in the order in which they were inserted into the table.
Notes
-
Unlike the processing of a hashed table when a primary key is used, a preceding sort using the statement
SORT
has no influence on the processing order when a secondary hash key is specified. -
If a secondary table key is specified, any
WHERE
condition must be optimizable. Otherwise a syntax error occurs or an exception is raised.
Addition 2
... WHERE log_exp
Effect
Static WHERE
condition. All rows are processed for which the condition after
WHERE
is met. If a static WHERE
condition is specified,
the row type of the internal table must be statically identifiable. WHERE
can be specified for all table categories.
A logical expression
log_exp
can be specified after WHERE
, in which the first operand of each
relational expression is a
component of the internal table. Any
comparison expression and the
predicate expression
IS INITIAL
can be specified as relational expressions. Other
predicates cannot be specified. The components of the internal
table must be specified as individual operands and not as part of an expression. Parenthesized character-like data objects cannot be used to specify a component dynamically here. The remaining operands of a relational expression are
general expression positions at which any
suitable individual operands or
expressions can be specified, but no components of the internal table. The specified components can have any data type. The relevant
comparison rules apply to the evaluation.
- When standard tables
are accessed without a secondary key being specified, the access is not optimized. This means that all
rows of the internal table are tested for the logical expression of the
WHERE
addition.
- When using a sorted key or a
hash key (that is, when accessing a
sorted table, a
hashed table, or a
secondary table key),
an attempt is made to optimize the access as described under
Optimization of the
WHERE
Condition. If the following prerequisites are not met:
- the entire logical expression (or a part of the expression) can be transformed to a key access,
- the transformable part of the logical expression has the same result as the resulting key access,
WHERE
condition cannot specify any duplicate or overlapping keys.
Duplicate key components can, however, be specified in the part of the logical expression whose relational expressions do not make a contribution to the optimized access.
Notes
-
When using a
WHERE
condition, note that the comparison rules for incompatible data types apply when comparing incompatible data objects. Here, the data types involved determine which operand is converted. If the additionsWITH TABLE KEY
andWITH KEY
of the statementREAD
are used or if the appropriate keys are specified in table expressions, however, the content of the specified data objects is always converted to the data type of the columns before the comparison. This can produce varying results. -
If possible, all operands of the logical expression should be in
compatible pairs, so enabling
the
WHERE
condition to be optimized. -
If a comparison expression with a
selection table is specified after
IN
as a logical expression, note that the expression at the initial table is always true and then all rows are edited.
Addition 3
... WHERE (cond_syntax)
Effect
Dynamic WHERE
Condition cond_syntax
can be specified as a character-like data object or
standard table with
character-like row type that, when the statement is executed and with the following exceptions, contains
the syntax of a logical expression (in accordance with the rules of the static WHERE
condition) or is initial. The following are not supported in a dynamic WHERE
condition:
- String expressions and bit expressions
- String functions and bit functions
- Constructor expressions
-
Table expressions
The syntax in cond_syntax
is, as in the ABAP Editor, not case-sensitive.
When an internal table is specified, the syntax can be distributed across multiple rows. If cond_syntax
is initial when the statement is executed, the logical expression is true. Invalid logical expressions raises an exception from the class CX_SY_ITAB_DYN_LOOP.
Security Note
If used wrongly, dynamic programming techniques can present a serious security risk. Any dynamic content
that is passed to a program from the outside must be checked thoroughly or escaped before being used
in dynamic statements. This can be done using the system class CL_ABAP_DYN_PRG or the predefined function escape
. See
Security Risks of Input from Outside.
Note
The dynamic WHERE
conditions is not evaluated for a blank table for optimization
reasons. Therefore, if an internal table is blank, and a logical expression has errors, no exception is raised.