Editing ABAP (section)

==CDS Views==
The ABAP Core Data Services (ABAP CDS) are the implementation of the general CDS concept for AS ABAP. ABAP CDS makes it possible to define semantic data models on the central database of the application server. On AS ABAP, these models can be defined independently of the database system. The entities of these models provide enhanced access functions when compared with existing database tables and views defined in ABAP Dictionary, making it possible to optimize Open SQL-based applications. This is particularly clear when an AS ABAP uses a SAP HANA database, since its in-memory characteristics can be implemented in an optimum manner.

The data models are defined using the data definition language (DDL) and data control language (DCL) provided in the ABAP CDS in the ABAP CDS syntax. The objects defined using these languages are integrated into ABAP Dictionary and managed here too.

CDS source code can only be programmed in the Eclipse-based ABAP Development Tools (ADT). The Data Definition Language (DDL) and the Data Control Language (DCL) use different editors.<ref>{{Cite web|url=https://help.sap.com/doc/abapdocu_740_index_htm/7.40/en-US/index.htm?file=ABENCDS.htm|title=ABAP Keyword Documentation|access-date=2019-07-11|archive-date=2019-07-11|archive-url=https://web.archive.org/web/20190711115146/https://help.sap.com/doc/abapdocu_740_index_htm/7.40/en-US/index.htm?file=ABENCDS.htm|url-status=live}}</ref>

===Features===
{| class="wikitable"
|-
! SAP NW ABAP !! SQL Joins !! SQL Set Operations !! SELECT Clauses
|-
| 7.40 SP05 || 
* INNER JOIN 
* LEFT OUTER JOIN 
* RIGHT OUTER JOIN 
|| 
* UNION
* UNION ALL
||
* WHERE
* GROUP BY
* HAVING
* AS
|-
| 7.40 SP08 || || ||
|-
| 7.50 || || ||
|-
| 7.51 || 
* CROSS JOIN 
|| 
||
|}

{| class="wikitable"
|-
! SAP NW ABAP !! Literals !! Arithmetic Operators !! Conditional Expressions
|-
| 7.40 SP05 ||
* In SELECT list, e.g. ''literal'' as FieldName
* As RHS value
|| 
* +
* –
* ∗
||
* Boolean operators
** NOT, AND, OR
* Comparison operators
** BETWEEN, =, <>, <, >, <=, >=, LIKE
** IS [NOT] NULL (Only in WHERE condition)
|-
| 7.40 SP08 || 
||
* / (Float-based division) 
||
|-
| 7.50 ||  ||  || 
|-
| 7.51  ||  ||  || 
* Function as RHS value
|}

{| class="wikitable"
|-
! SAP NW ABAP !! Aggregate functions !! Numeric functions !! String functions
|-
| 7.40 SP05 ||
* AVG( [DISTINCT] )
* MAX
* MIN
* SUM( [DISTINCT] )
* COUNT( [DISTINCT] )
* COUNT(*)
||
* CEIL
* MOD
||
* SUBSTRING
* LPAD
|-
| 7.40 SP08 ||  ||
* ABS 
* DIV (Integer-based division)
* DIVISION (Decimal-based division)
* FLOOR
* ROUND
|| 
* CONCAT
* REPLACE
|-
| 7.50 || || || 
* CONCAT_WITH_SPACE
* INSTR
* LEFT
* LENGTH
* LTRIM
* RIGHT
* RPAD
* RTRIM
|-
| 7.51 || 
* AVG( [AS] ) to specify return type
|| 
* FLTP_TO_DEC
|| 
* UPPER
* LOWER
|}

{| class="wikitable"
|-
! SAP NW ABAP !! Byte string functions !! Date and time functions  !! Other functions
|-
| 7.40 SP05 ||  ||  || 
* CAST to built-in DDIC types, e.g. abap.fltp
|-
| 7.40 SP08 ||  ||  || 
* COALESCE
* CURRENCY_CONVERSION
* UNIT_CONVERSION
* DECIMAL_SHIFT
|-
| 7.50 || 
* BINTOHEX
* HEXTOBIN
|| 
* DATS_DAYS_BETWEEN
* DATS_ADD_DAYS
* DATS_ADD_MONTHS
* DATS_IS_VALID
* TIMS_IS_VALID
* TSTMP_IS_VALID
* TSTMP_CURRENT_UTCTIMESTAMP
* TSTMP_SECONDS_BETWEEN
* TSTMP_ADD_SECONDS
|| 
* CAST
** to data elements, e.g. CHAR80
** can be nested
|-
| 7.51 ||  || 
* ABAP_SYSTEM_TIMEZONE
* ABAP_USER_TIMEZONE
* TSTMP_TO_DATS
* TSTMP_TO_TIMS
* TSTMP_TO_DST
* DATS_TIMS_TO_TSTMP
|| 
* CAST
** PRESERVING TYPE
** SSTRING to other types
** CLNT, LANG, TIMS, UNIT to data elements of type CHAR and SSTRING
** CHAR, SSTRING, NUMC to ACCP and vice versa
** Aggregate function as operand
|}

{| class="wikitable"
|-
! SAP NW ABAP !! Conditional (CASE) expressions !! Extensibility !! (Unmanaged) Associations
|-
| 7.40 SP05 ||
* "Simple" CASE (behaves like switch statement)
* Nested CASE statements
|| 
* $EXTENSION.* (support for database table extensions)
||
* Path expressions in
** SELECT list
** FROM clause
** WHERE clause
** HAVING clause
* Filter conditions in path expressions, e.g. {{Code|1=Products._Texts[ lagu = 'EN' ] as english_name|2=abap}}
|-
| 7.40 SP08 
|| 
* "Searched" CASE (behaves like if ... else if) 
||
* EXTEND VIEW 
||
|-
| 7.50 
||
* CASE expressions can be used as operands in CAST functions 
||
* EXTEND VIEW with input parameters, path expressions, conversions, date and time functions 
||
|-
| 7.51 
||
* Function as RHS value 
||
* EXTEND VIEW with aggregate functions, GROUP BY clauses and UNIONs 
||
* Association definitions in views with UNIONs
* Default filters for associations (WITH DEFAULT FILTER)
* Cardinality "to many" (*:) can be specified in path filters
|}

{| class="wikitable"
|-
! SAP NW ABAP !! Session variables !! Input parameters !! Other
|-
| 7.40 SP05 ||  ||  || 
* KEY elements
|-
| 7.40 SP08 ||  || 
* input parameters on most DBs
||
|-
| 7.50 || 
* $session.user (sy-uname)
* $session.client (sy-mandt)
* $session.system_language (sy-langu)
 || 
* Input parameters on AnyDB
|| 
* Table function (SAP HANA only)
|-
| 7.51 ||
* $session.system_date (sy-datum) 
||
|| 
* Metadata extensions
|}
<ref>{{Cite web|url=https://blogs.sap.com/2015/02/02/core-data-services-cds-abap-feature-matrix/|title=Core Data Services (CDS) ABAP Feature Matrix &#124; SAP Blogs|date=2 February 2015|access-date=11 July 2019|archive-date=11 July 2019|archive-url=https://web.archive.org/web/20190711142232/https://blogs.sap.com/2015/02/02/core-data-services-cds-abap-feature-matrix/|url-status=live}}</ref>