ABAPMETHOD_BY_DB_PROC - METHOD BY DB PROC

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METHOD, BY DATABASE PROCEDURE, FUNCTION, GRAPH WORKSPACE

METHOD meth BY DATABASE PROCEDURE$|FUNCTION$|GRAPH WORKSPACE
            FOR db
            LANGUAGE db_lang
            $[OPTIONS db_options$]
            $[USING   entities$]
            $[USING   SCHEMA schema1 OBJECTS db_entities$]
            $[USING   SCHEMA schema2 OBJECTS db_entities$]
            ... .
  ...
ENDMETHOD.

Additions

1. ... FOR db

2. ... LANGUAGE db_lang

3. ... OPTIONS db_options

4. ... USING entities

5. ... USING SCHEMA schema OBJECTS db_entities

Effect

Implements an AMDP procedure or an AMDP function in an AMDP class. The addition BY DATABASE PROCEDURE or BY DATABASE FUNCTION can be specified in the implementation part of a global class that contains an appropriate tag interface IF_AMDP_MARKER_... for AMDP classes.

• The addition BY DATABASE PROCEDURE defines an AMDP procedure implementation for implementing a database procedure.

• The addition BY DATABASE FUNCTION defines an AMDP function implementation for implementing a database function.

• The addition BY DATABASE GRAPH WORKSPACE defines a graph workspace that can be consumed by a graph procedure using GraphScript.

The parameter interface of the method declared in the declaration part must meet the prerequisites for AMDP procedure implementations or AMDP function implementations. The parameter interface of an AMDP function implementation that implements a CDS table function is taken from the definition of the CDS table function specified after the addition FOR TABLE FUNCTION in the declaration of the method.

The addition FOR db defines the database system where the method is used. The addition LANGUAGE defines the database-specific language in which the method is implemented. OPTIONS is used to specify database-specific options. USING is used to declare database objects managed by ABAP that are used in the AMDP method.

Note

If the current AS ABAP does not have sufficient authorizations to manage database procedures or database functions in its database system, syntax errors can occur in AMDP methods. Missing authorizations can be identified using transaction SICK.

AMDP - Examples

Addition 1

... FOR db

Effect

Determines the database system for which the AMDP method is used. The AMDP class must contain the appropriate tag interface. The following table shows the syntax that can be specified for db, the database system it identifies, and the required tag interface.

db	Database System	Tag Interface
HDB	SAP HANA database	IF_AMDP_MARKER_HDB

The AMDP method can only be called in an AS ABAP whose standard database is managed by the specified database system. Otherwise a runtime error occurs.

Notes

• An AMDP class can contain multiple tag interfaces for different database systems and can therefore implement AMDP methods in different languages.

• Additional regular methods can be provided to make an AMDP class with AMDP procedure implementations public. These methods call the AMDP methods depending on the database system of the current standard AS ABAP database. In database systems that do not yet support AMDP, an alternative implementation in or Native SQL can be created in regular methods.
  
  

Addition 2

... LANGUAGE db_lang

Effect

Determines the database-specific language in which the AMDP is implemented. The following table shows the syntax for db_lang used to specify the language depending on the specified database system db, the meaning, and a link to further information.

db	db_lang	Language	More Information
HDB	SQLSCRIPT	SQLScript	SQLScript for the SAP HANA Database
HDB	SQL	DDL	Not yet documented
HDB	GRAPH	GraphScript	Graph Processing
HDB	LLANG	L	L for the SAP HANA database (for internal SAP use only and only for AMDP procedure implementations)

The ABAP syntax check examines the implementation of the method for the specified language as far as possible. This is possible only if the check takes place on an AS ABAP whose standard database is managed by the specified database system. The check is performed with respect to the currently installed version of the database. No checks take place on an AS ABAP with a different database system.

Addition 3

... OPTIONS db_options

Effect

Specifies database-specific options for the AMDP procedure or function. The following table shows the syntax for option depending on the specified database system db and the associated meaning.

db	option	Meaning
HDB	READ-ONLY	Only reads are allowed on the database tables in the database procedure or database function. Other AMDP methods can be called only if they are also flagged as READ-ONLY.
HDB	DETERMINISTIC	For AMDP scalar functions only. If a query calls an AMDP scalar function more than once with the same values for the input parameters and with the option DETERMINISTIC, the function is performed only once, and the result is buffered for the duration of the query. In AMDP scalar functions like this, no functions are allowed that could return different values in different calls. For more information, see SAP Hana SQLScript Reference.
HDB	SUPPRESS SYNTAX ERRORS	For internal SAP use only: If the AMDP procedure accesses database objects not managed by ABAP that do not yet exist at the time of the syntax check, only syntax warnings are raised and not syntax errors. If a required object is missing at runtime, a catchable exception is raised.

The option READ-ONLY can also be specified with the addition AMDP OPTIONS in the declaration of an AMDP method. It applies when specified either in the implementation or in the declaration of the method, or in both places.

These options are optional, with the following exception: READ-ONLY must be specified at least once in the implementation of an AMDP function or an L procedure.

The syntax check examines the specified options at runtime.

Note

The option SUPPRESS SYNTAX ERRORS does not affect database objects managed by ABAP that are specified after USING.

Addition 4

... USING entities

Effect

Declares the DDL object in methods using the syntax ... BY DATABASE GRAPH WORKSPACE ....

In other cases, it declares the database objects managed by ABAP accessed in the AMDP procedure or function. The following must be specified after USING:

• All CDS views, CDS table functions, and CDS hierarchies using the name of the CDS entity

• All database tables and DDIC views from the ABAP Dictionary

• All procedures and functions managed by AMDP

These tables, views, and procedures are from the current ABAP database schema used in the procedure. If used in the procedure, the names of the database objects must be specified without specifying the database schema.

• For CDS views and CDS table functions, these are the names of the associated SQL views or AMDP functions.

• The database objects of database tables and DDIC views from the ABAP Dictionary have the same names as in the ABAP Dictionary.

• An AMDP procedure or function is specified using the syntax class=>meth. Here, class is the name of its AMDP class and meth is the name of the AMDP procedure implementation or function implementation.

The name of a CDS view linked with a CDS-managed DDIC view can be specified after USING. In the case of a CDS table function, the name of the associated AMDP function can also be specified. However, if a CDS entity is specified, all other database objects of CDS entities must be also be specified using this entity.

Each database object specified after USING must also be used in the procedure or function. Any database objects other than those above managed by ABAP cannot be specified after USING and the procedure or function cannot be used to access database objects not specified after USING, with the following exceptions:

• Database objects in the current database schema if they are in the namespace of the namespace prefix/1BCAMDP/. If used in the procedure or function, they must be specified directly and without specifying the database schema.

• Database objects in a different database schema using their fully qualified names, for which logical schemas can also be used.

With the exception of the namespace /1BCAMDP/, database objects from the current database schema can therefore only be accessed in a database procedure or database function managed by AMDP only if they are managed by ABAP and specified after USING.

Notes

• Explicit declarations of database objects used in the procedure or function are required for various static checks, such as where-used lists or package checks, and enable the visibility of an AMDP method to be passed to the database level.

• An object specified after USING must be visible here. An AMDP method from a different class can be specified only if it can be used by the current class and, accordingly, can only be called in the database procedure or database function. This applies the visibility concept of ABAP Objects to the database system, even if it does not have a similar concept.

• In the case of database tables in the ABAP Dictionary specified after USING, the AMDP framework ensures that the order of the fields defined in the dictionary is respected when the tables are accessed statically, which may be different from the order on the database.

• When an AMDP method class=>meth is specified after USING, the ABAP runtime framework identifies this as a use of the class class and its static constructor is executed before the first call of the AMDP method. If an AMDP procedure or function uses other AMDP procedures or functions, it can therefore be assumed that the corresponding static constructor was executed.

• AMDP methods in the same class must also be specified after USING, if they are used in the procedure or function.

• For CDS views and CDS table functions, it is recommended that the CDS entity is specified.

• A database-specific option SUPPRESS SYNTAX ERRORS specified after OPTIONS does not affect the database objects managed by ABAP that are specified after USING. The syntax error cannot be suppressed for these.

• The namespace /1BCAMDP/ is intended for temporary database tables, views, or database procedures or database functions of the current database schema that are to be accessed in AMDP procedures or functions.

• The addition USING cannot be specified in the implementation of L procedures.
  
  

Addition 5

... USING SCHEMA schema OBJECTS db_entities

Effect

Declares a logical database schema and the database objects it contains that are accessed by the AMDP procedure or function.

For schema, only logical database schemas that the current ABAP database schema can be mapped to can be specified. The addition USING SCHEMA must be specified for each logical database schema of this type that is used in the AMDP method in a macro $ABAP.schema. The effect of this addition depends on the physical database schema that is mapped to the logical database schema schema.

• If the current ABAP database schema is mapped to the logical database schema using the predefined name :abap_db_schema, all database tables and views from the ABAP Dictionary used in the procedure must be specified after OBJECTS. For these dictionary objects, the addition USING SCHEMA behaves in the same way as the addition USING. AMDP-managed procedures and functions cannot, however, be specified after OBJECTS.

• If a different database schema or no database schema is mapped to the logical database schema, any names can be specified after OBJECTS that comply with the naming conventions for database tables and views in the ABAP Dictionary.

The addition USING SCHEMA must be specified after the addition USING and only one USING SCHEMA addition is allowed for a logical database schema schema.

Notes

• The addition USING SCHEMA is intended for scenarios in which database objects are defined in any database schema in some systems and in the ABAP database schema in others. If database objects like this are specified accordingly after a suitable logical database schema, the AMDP procedure can be transported between these systems without the need for syntax modifications. It is sufficient to make the correct mapping in each system in transaction DB_SCHEMA_MAP.

• It is pointless to map the current ABAP database schema to a logical database schema specified after schema explicitly, that is, not using the predefined name :abap_db_schema, since this logical schema cannot be used in the macro $ABAP.schema.

• No logical HDI container can be specified for schema.

• If AMDP-managed procedures and functions are used in the AMDP method, they cannot be specified after USING SCHEMA and must always be specified after USING instead.

• If the flag that allows mappings of the ABAP database schema is changed for an existing logical database schema, the above rules for using the addition USING SCHEMA lead to syntax errors in AMDP classes that already use this logical database schema.

Access to Database Schemas

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