Get Example source ABAP code based on a different SAP table
VERSION 5 OUT • CL_OSQL_REPLACE ABAP_CLASS
CL_OSQL_REPLACE, Replacement Service The system class CL_OSQL_REPLACE implements a replacement service that can be used to redirect access to data sources in AB-SQL statements during the execution of unit tests in ABAP Unit. The system class CL_OSQL_REPLACE can only be used in test classes of ABAP Unit. ITOC
Defining Replacement Rules The static method ACTIVATE_REPLACEMENT of the system class CL_OSQL_REPLACE is used to define replacement rules.
A three-column internal table is passed to the parameter REPLACEMENT_TABLE:
The first column SOURCE contains the name of a data source defined in the ABAP Dictionary, namely a DDIC database table, a DDIC view, or a non-abstract CDS entity.
The second column TARGET contains the name of a database object in the current database to which an AB-SQL access to the data source named in the first column is redirected.
The third column SCHEMA contains the name of a database schema to be searched to find the database object from the second column. If the third column is empty, the ABAP database schema is used.
An ID can be passed to the parameter FLG_DML to define whether the redirection also applies to write AB-SQL statements:
If the value abap_false is passed to the parameter FLG_DML , the redirection only applies to queries, that is, to the main queries of reads and for the subqueries of all accesses.
If the value abap_true is passed to the parameter FLG_DML, the redirection also applies to the DDIC database tables to be changed by write accesses.
An ID can be passed to the parameter FLG_SURVIVE_SUBMIT to define whether the redirection also applies to called programs:
If the value of abap_false is passed to the parameter FLG_SURVIVE_SUBMIT, the redirection applies only to the current program.
If the value of abap_true is passed to the parameter FLG_SURVIVE_SUBMIT, the redirection also applies to programs called using SUBMIT, CALL TRANSACTION, and CALL DIALOG. The redirection can be made to any database objects, in particular to variants of the DDIC database tables or DDIC views defined in the ABAP Dictionary. The database objects that are redirected to must have the same structure as the redirected object, otherwise the result is database specific and exceptions can occur. A successful redirection applies to the entire execution of a unit test until the ABAP_ISESS is ended or there is another redirection. A redirection is ended explicitly if an empty internal table is passed to the method ACTIVATE_REPLACEMENT .
Latest notes:
From a technical perspective, a redirection replaces the names of the database objects in the platform-dependent SQL statements, which the database interface generates from the AB-SQL statements and passes to the database system.
Redirection of the data sources used by AB_SQL is used during unit tests so that test tables and test data can be processed instead of the actual tables and their data. In particular, this enables testing of system programs that access system tables.
In the case of redirections in called programs using the parameter FLG_SURVIVE_SUBMIT, program calls using SUBMIT without the addition AND RETURN are pointless. ABAP_HINT_END
Additional Methods As well as the method ACTIVATE_REPLACEMENT, CL_OSQL_REPLACE has the following methods:
The methods IS_REPLACEMENT_ACTIVE and IS_REPLACEMENT_ACTIVE_DML are used to check whether a redirection is active and whether it also applies to writes.
The methods SET_ACTIVE_FOR_DML and TOGGLE_ACTIVE_FOR_DML are used to set or change the setting for writes for an existing redirection.
Restrictions and Special Features
Data Sources of Reads The following applies to data sources of reads:
The data source of a read can only be redirected to an object defined in the ABAP Dictionary if the object appears in the database under the name that it is defined with in the ABAP Dictionary.
To redirect a read from a DDIC projection view to another data source, the underlying DDIC database table can be redirected.
It is not possible to redirect to the following:
Projection views
CDS entities
If the data source of a subquery in the WHERE condition of a write statement is redirected to the target of the write, the behavior is undefined and unexpected errors may occur.
The following should be noted for CDS entities :
If a read is redirected to a CDS view or a CDS table function for which one or more CDS roles are defined as part of CDS access control, the associated access conditions are evaluated independently of the target of the redirection. CDS roles that are defined for the target of a redirection are ignored.
The following should be noted for CDS table functions:
A CDS table function can only be redirected to a table function. However, this does not have to be an AMDP function.
If a direct or indirect read of a CDS table function is redirected to another data source, the static constructor of the AMDP class in which the associated AMDP table function is implemented is executed.
If a read of a data source is redirected to an AMDP table function that is known in the current AS ABAP, the AMDP framework creates the associated variant in the database if necessary, and the static constructor of the associated AMDP class is executed.
If the source or target of a redirection is a DDIC database table of the ABAP database schema defined in ABAP Dictionary, for which a replacement object is defined, the redirection is evaluated first and then the replacement object.
If a data source of a read is redirected to a DDIC database table for which a replacement object is defined, a redirect to the replacement object is made.
If a DDIC database table is redirected for which a replacement object is defined, the redirection is applied. The replacement object is ignored.
If a replacement object is defined for a DDIC database table and the replacement object is redirected, the redirection is ignored. The replacement object is accessed here.
A redirection always bypasses table buffering.
Targets of Writes The same restrictions apply to the target of a write as to the data sources of reads, if applicable. In addition, targets of writes cannot be redirected to the following objects defined in the ABAP Dictionary:
DDIC views
DDIC database tables with active table buffering
DDIC database tables with active logging Writes to a projection view cannot be redirected if the lines to be changed are determined by a work area or an internal table. Therefore, it is only possible to redirect accesses to the DDIC database table of a DDIC projection view if there are no writes to the view, except with the statements DELETE with a WHERE condition or UPDATE with the addition SET. Otherwise, a runtime error occurs.
Example ABAP Coding
See the program DEMO_CL_OSQL_REPLACE .
A production class prod reads data from the DDIC database table SCARR in the method select, and deletes a line from this table in the method delete.
The test class test_prod tests the methods of the production class.
In the method setup, access to SCARR is redirected for read and write AB-SQL statements with cl_osql_replace=>activate_replacement to a test table DEMO_TEST_SCARR, which was defined in the ABAP Dictionary as a copy of SCARR. The database schema of DEMO_TEST_SCARR is passed here explicitly for demonstration purposes, but this is not necessary for database objects from the ABAP database schema.
In the method setup, the test table DEMO_TEST_SCARR is supplied with two lines of test data from an internal table testdata .
In the method test, the method select is called and the return value is compared with the internal table testdata. Calling the method delete deletes a row of test data from the test table and checks that the deleted row no longer exists.
In the method teardown, the test data is deleted from the test table. Execution of the unit test should always be successful, regardless of the content of SCARR. ABAP_EXAMPLE_END
