Inserting Lines into Tables
You can insert one or several lines into internal tables using the INSERTstatement.
To add a line to an internal table, use the statement:
INSERT line INTO TABLE itab.
line is either a work area that is compatible with the line type, or the expression INITIAL LINE. The work area must be compatible because the fields in the table key must be filled from fields of the correct type. INITIAL LINE inserts an initialized blank line suitable for the type.
If the internal table has a unique key, lines whose key already exists in the table will not be inserted and sy-subrc is set to 4. When the system successfully adds a line to the table, sy-subrc is set to 0.
Lines are added to internal tables as follows:
- Standard tables
The line is appended to the end of the internal table. The statement works in the same way as the specific statement APPEND for appending lines .
- Sorted tables
The line is inserted into the table according to the table key. If the key is non-unique, duplicates are inserted above the existing entry with the same key. The runtime for the operation increases logarithmically with the number of existing table entries.
- Hashed tables
The table is inserted into the internal hash administration according to the table key.
To add several lines to an internal table, use the statement:
INSERT LINES OF itab1 [FROM n1] [TO n2] INTO TABLE itab2.
itab1 and itab2 are tables with a compatible line type. The system inserts the lines of table itab1 one by one into table itab2 using the same rules as for single lines.
If itab1 is an index table, you can specify the first and last lines of itab1 that you want to append in n1 and n2.
Depending on the size of the tables and where they are inserted, this method of inserting lines of one table into another can be up to 20 times faster than inserting them line by line in a loop.
Inserting a Single Line
REPORT demo_int_tables_insert.
DATA: BEGIN OF line, land(3) TYPE c, name(10) TYPE c, age TYPE i, weight TYPE p DECIMALS 2, END OF line.
DATA itab LIKE SORTED TABLE OF line WITH NON-UNIQUE KEY land name age weight.
line-land = 'G'. line-name = 'Hans'.line-age = 20. line-weight = '80.00'.INSERT line INTO TABLE itab.
line-land = 'USA'. line-name = 'Nancy'.line-age = 35. line-weight = '45.00'.INSERT line INTO TABLE itab.
line-land = 'USA'. line-name = 'Howard'.line-age = 40. line-weight = '95.00'.INSERT line INTO TABLE itab.
line-land = 'GB'. line-name = 'Jenny'.line-age = 18. line-weight = '50.00'.INSERT line INTO TABLE itab.
line-land = 'F'. line-name = 'Michele'.line-age = 30. line-weight = '60.00'.INSERT line INTO TABLE itab.
line-land = 'G'. line-name = 'Karl'.line-age = 60. line-weight = '75.00'.INSERT line INTO TABLE itab.
LOOP AT itab INTO line. WRITE: / line-land, line-name, line-age, line-weight.ENDLOOP.
The list output is:
F Michele 30 60,00G Hans 20 80,00G Karl 60 75,00GB Jenny 18 50,00USA Howard 40 95,00USA Nancy 35 45,00
Single lines are inserted into a sorted internal table.
Inserting Several Lines
REPORT demo_int_tables_insert_lines.
DATA: BEGIN OF line, col1 TYPE i, col2 TYPE i, END OF line.
DATA: itab LIKE STANDARD TABLE OF line, jtab LIKE SORTED TABLE OF line WITH NON-UNIQUE KEY col1 col2.
DO 3 TIMES. line-col1 = sy-index. line-col2 = sy-index ** 2. APPEND line TO itab. line-col1 = sy-index. line-col2 = sy-index ** 3. APPEND line TO jtab.ENDDO.
INSERT LINES OF itab INTO TABLE jtab.
LOOP AT jtab INTO line. WRITE: / sy-tabix, line-col1, line-col2.ENDLOOP.
The list output is:
1 1 1 2 1 1 3 2 4 4 2 8 5 3 9 6 3 27
The example creates two internal tables with the same line type but different table types. Each is filled with three lines. Then, the entire table itab is sorted into the sorted table jtab.
The INSERT statement allows you not only to insert lines in any type of internal table, but also to change them using a line index. You can insert either a single line or a group of lines into index tables using the index.
To insert a line into an index table, use the statement:
INSERT line INTO itab [INDEX idx].
line is either a work area wa that is convertible to the line type, or the expression INITIAL LINE. If you use wa, the system adds a new line to the internal table itab and fills it with the contents of the work area. INITIAL LINE inserts an initialized blank line suitable for the type.
If you use the INDEX option, the new line is inserted before the line that has the index idx. After the insertion, the new entry has the index idx and the index of the following lines is incremented by 1. If the table contains idx -1 lines, the new line is added after the last line. If the table has less than idx - 1 lines, the new line cannot be inserted, and sy-subrc is set to 4. When the system successfully adds a line to the table, sy-subrc is set to 0.
Without the INDEX addition, you can only use the above statement within a LOOP. Then the new line is inserted before the current line; idx is implicitly set to sy-tabix.
Appending lines to standard tables and sorted tables with a non-unique key works regardless of whether lines with the same key already exist in the table. Duplicate entries may occur. A runtime error occurs if you attempt to add a duplicate entry to a sorted table with a unique key. Equally, a runtime error occurs if you violate the sort order of a sorted table by appending to it.
To add several lines to an internal table, use the statement:
INSERT LINES OF itab1 INTO itab2 [INDEX idx].
The system inserts the lines of the entire table itab1 one by one into itab2 using the same rules as for single lines. itab1 can be any type of table. The line type of itab1 must be convertible into the line type of itab2.
When you append an index table to another index table, you can specify the lines to be appended as follows:
INSERT LINES OF itab1 [FROM n 1 ] [TO n 2 ] INTO itab2 [INDEX idx].
n 1 and n 2 specify the indexes of the first and last lines of itab1.
Depending on the size of the tables and where they are inserted, this method of inserting lines of one table into another can be up to 20 times faster than inserting them line by line in a loop.
REPORT demo_int_tables_insert_ind_1.
DATA: BEGIN OF line, col1 TYPE i, col2 TYPE i, END OF line.
DATA itab LIKE TABLE OF line.
DO 2 TIMES. line-col1 = sy-index. line-col2 = sy-index ** 2. APPEND line TO itab.ENDDO.
line-col1 = 11. line-col2 = 22.INSERT line INTO itab INDEX 2.
INSERT INITIAL LINE INTO itab INDEX 1.
LOOP AT itab INTO line. WRITE: / sy-tabix, line-col1, line-col2.ENDLOOP.
The list output is:
1 0 0 2 1 1 3 11 22 4 2 4
The example creates an internal table itab and fills it with two lines. A new line containing values is inserted before the second line. Then, an initialized line is inserted before the first line.
REPORT demo_int_tables_insert_ind_2.
DATA: BEGIN OF line, col1 TYPE i, col2 TYPE i, END OF line.
DATA itab LIKE TABLE OF line.
DO 2 TIMES. line-col1 = sy-index. line-col2 = sy-index ** 2. APPEND line TO itab.ENDDO.
LOOP AT itab INTO line. line-col1 = 3 * sy-tabix. line-col2 = 5 * sy-tabix. INSERT line INTO itab.ENDLOOP.
LOOP AT itab INTO line. WRITE: / sy-tabix, line-col1, line-col2.ENDLOOP.
The list output is:
1 3 5 2 1 1 3 9 15 4 2 4
The example creates an internal table itab and fills it with two lines. Using a LOOP construction, the program inserts a new line before each existing line.
REPORT demo_int_tables_insert_ind_3.
DATA: BEGIN OF line, col1 TYPE i, col2 TYPE i, END OF line.
DATA: itab LIKE TABLE OF line, jtab LIKE itab.
DO 3 TIMES. line-col1 = sy-index. line-col2 = sy-index ** 2. APPEND line TO itab. line-col1 = sy-index. line-col2 = sy-index ** 3. APPEND line TO jtab.ENDDO.
INSERT LINES OF itab INTO jtab INDEX 1.
LOOP AT jtab INTO line. WRITE: / sy-tabix, line-col1, line-col2.ENDLOOP.
The list output is:
1 1 1 2 2 4 3 3 9 4 1 1 5 2 8 6 3 27
The example creates two internal tables of the same type. Each is filled with three lines. Then, the entire table itab is inserted before the first line of jtab.