Selecting and Working with Data Internal Tables Again

1
Selecting and Working with Data(Internal Tables
Again)

• MINS298c
• Fall 1998
• Chapters 10-12

2
Overview

• Subroutines
• Internal Tables Again
• Select
• all, some, part
• Working with it once you got it
• Loop
• Read
• Forms
• Study Hints

3
Subroutines (Normal Scope)
Line
Program DATA A, B, C
According to normal rules of scope,
which Write statements are legal and which are
not?
1 2 3 4 5 6
Write A Write F
Form DATA X, Y, Z
Write A Write F
Form DATA D, E, F
Write A Write F
4
Subroutines

• Defined by FORM and ENDFORM
• Executed with PERFORM verb
• Can call by value or call by reference
• by reference is implied
• VALUE clause passes by value
• ABAP does number and type checking at runtime

5
Example
ASSUME x, y, and z are integer and
x 4 y 5 z 10 Write x, y,
z. Perform add_em changing value(x) y
changing z. Write x, y, z. Form add_em a1 a2
changing a3. a1 a1 1. a2 a2 2.
a3 a1 a2.
6
Internal Tables

• TABLES defines which external database table your
  program uses
• OCCURS statement creates an internal table
• The clause WITH HEADER LINE creates a work area
  (WA) structure defined like the table

7
Header lines

• tables flight
• data my_flight like flight occurs 0 times
• with header line.

my program
flight table
8
Header lines

• tables flight
• data my_flight like flight occurs 0 times
• with header line.

my program
flight
flight table
9
Header lines

• tables flight
• data my_flight like flight occurs 0 times
• with header line.

my program
flight
flight table
my_flight
my_flight
10
Getting Data

• SELECT INTO
• SELECT APPENDING
• INSERT INDEX n
• MOVE

11
SELECT INTO

• SELECT FROM FLIGHT
• INTO TABLE MY_FLIGHT.

my program
flight
flight table
my_flight
my_flight
12
SELECT INTO

• SELECT FROM FLIGHT
• INTO TABLE MY_FLIGHT.

my program
flight
flight table
my_flight
my_flight
13
SELECT INTO

• SELECT FROM FLIGHT
• INTO TABLE MY_FLIGHT.

my program
flight
flight table
my_flight
my_flight
14
SELECT INTO

• SELECT FROM FLIGHT
• INTO TABLE MY_FLIGHT.

my program
flight
flight table
my_flight
my_flight
15
SELECT INTO

• SELECT FROM FLIGHT
• INTO TABLE MY_FLIGHT.

my program
flight
flight table
my_flight
my_flight
16
SELECT INTO

• SELECT FROM FLIGHT
• INTO TABLE MY_FLIGHT.

my program
flight
flight table
my_flight
my_flight
17
SELECT INTO

• SELECT FROM FLIGHT
• INTO TABLE MY_FLIGHT.

my program
flight
flight table
my_flight
my_flight
18
SELECT INTO

• SELECT FROM FLIGHT
• INTO TABLE MY_FLIGHT.

my program
flight
flight table
my_flight
my_flight
19
Working Backwards

• Given the code below, what are the likely data,
  table or type statements required.
• Identify the tables, the WAs, and data types
• SELECT FROM CUSTOMERS.
• MOVE-CORRESPONDING CUSTOMERS TO
  CUSTOMER_CITIES.
• APPEND CUSTOMER_CITIES.
• ENDSELECT.

20
SELECT and the WHERE clause

• The WHERE clause limits the records selected to
  those matching the condition(s).
• In general, a condition is composed of
• table-name operator value
• Standard Operators
• eq, ne, lt, le, gt, ge
• New Operators
• between, like, in (list), selopt (Select-Option)

21
WHERE Examples

• WHERE table-name operator value
• WHERE order_date 19990101
• WHERE cust_name like E
• WHERE cust_name line B_ll
• WHERE cust_name like E AND
• order_date 19990101

22
SELECT statistics

• System will keep track of and report some basic
  statistics based upon your SELECT statement
• Statistics
• COUNT counts valid records
• MAX, MIN, AVG, SUM results on numeric fields
• Usage
• SELECT COUNT() FROM customers
• SELECT MAX(inv-owed) FROM invoices

23
Header vs Table

• SELECT FROM CUSTOMERS INTO TABLE ALL_CUSTOMERS.
• SELECT SINGLE FROM CUSTOMERS WHERE ID
  00000017.

All_Customers
Header
customers
Body
All_Customers
Header
customers
Body
24
Selecting Fields

• SELECT db-field1 db-field2
• INTO (itab-field1, itab-field2)
• FROM db-table.
• SELECT id name
• INTO (cid,cname)
• FROM customers

cid, cname
25
Selecting Fields

• ABAP uses the domains or data to permit
  selections by the user
• Identify the variables you wish filled in and
  ABAP builds the interface at runtime
• SELECT-OPTIONS command

26
How to Work with Internal Tables

• Sorting
• SORT itab
• SORT itab BY field1 field2 .
• Looping
• uses header line or INTO clause
• LOOP AT itab.
• can be nested
• can be selective
• Read

27
SORT itab BY field1 field2 .

• SORT my_table BY field1 field2 DESCENDING

field1 field2
ABC ABC ABC DEF XYZ XYZ XYZ
3 2 1 8 5 3 1
28
LOOP AT itab.

• LOOP AT My_table.
• WRITE / My_Table-field1
• ENDLOOP.

my_table
my_table
sy-tabix
29
LOOP AT itab.

• LOOP AT My_table.
• WRITE / My_Table-field1
• ENDLOOP.

my_table
my_table
sy-tabix
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LOOP AT itab.

• LOOP AT My_table.
• WRITE / My_Table-field1
• ENDLOOP.

my_table
Field1
my_table
sy-tabix
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LOOP AT itab INTO wa.

• LOOP AT My_table INTO holder.
• WRITE / My_Table-field1
• ENDLOOP.

holder
my_table
sy-tabix
32
LOOP AT itab INTO waWHERE condition.

• LOOP AT My_table INTO holder
• WHERE amount_owed gt 1000.
• WRITE / My_Table-field1
• ENDLOOP.

holder
my_table
sy-tabix
33
READ TABLE itab

• WITH KEY field condition
• finds first occurrence of key field which matches
  the condition
• can use BINARY SEARCH clause for binary search
• INDEX n
• direct read of the record at the location n

34
Study Hints

• Concepts based
• structures, fields, tables
• multi-language
• Verb basics
• Types
• Tables
• with and w/o header lines
• how to get data in
• how to get data out
• Simple loops

35
In Class Assignment

• Write a program to identify the following
  information about the TABLE sflight
• average prices of tickets
• the highest and lowest tickets available
• number of records in the table.