EXEC SQL - Host Variables
Host variables are global or local variables (usually variables) declared in the ABAP program that are used in operand positions of embedded
Native SQL statements.
Named data objects
can be identified by an escape character (a colon
:) placed in front of the
names of the data objects. Instead of the data object itself, a field symbol to which the data object is assigned can be specified. Dereferenced data reference variables cannot be dereferenced.
Only flat elementary fields and flat structures with elementary components can be used as host variables, with one
exception. If a structure is listed in a Native SQL
INTO, it is converted by the Native SQL interface as if its components were listed as individual fields separated by commas.
SELECT statement, the SAP-specific addition
can be specified between
INTO and an individual host variable. This addition
has the effect that the host variable is treated like a structure, even if a non-typed formal parameter
or a non-typed field symbol is specified. Otherwise, when multiple values are being passed, depending on the platform, either the first value only is passed or an exception occurs.
When assignments are made between host variables and fields in database tables, the Native SQL interface passes a description of type, size, and storage location of the ABAP data objects used to the database system. The actual database accesses and conversions are usually executed directly by the corresponding operations of the database system. In some cases, however, the Native SQL interface executes extensive compatibility checks.
The indicator variables provided in the SAP standard, which can be specified after an operand to identify null values, can be specified in static Native SQL by a host variable that has to be of an external data type INT2.
Like the example for literals; the row to be read is
here also specified using host variables. The addition
STRUCTURE is specified
INTO. However, this is not necessary since
can be identified statically as a structure. The structure
wa is handled
INTO clause as if all subfields were listed separately:
INTO :wa-cityfrom, :wa-cityto.
PARAMETERS: p_carrid TYPE spfli-carrid, p_connid TYPE spfli-connid. DATA: BEGIN OF wa, cityfrom TYPE spfli-cityfrom, cityto TYPE spfli-cityto, END OF wa. EXEC SQL. SELECT cityfrom, cityto INTO STRUCTURE :wa FROM spfli WHERE mandt = :sy-mandt AND carrid = :p_carrid AND connid = :p_connid ENDEXEC.