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NAME: dbnumrets
FUNCTION:
Determine the number of return parameter values generated by a
stored procedure.
SYNTAX:
int dbnumrets(dbproc)
DBPROCESS *dbproc;
COMMENTS:
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o dbnumrets() provides the number of return parameter values
returned by the most recent EXECUTE statement or remote pro-
cedure call on a stored procedure.
o Transact-SQL stored procedures can return values for specified
"return parameters." Changes made to the value of a return
parameter inside the stored procedure are then available to the
program that called the procedure. This is analogous to the
"pass by reference" facility available in some programming
languages.
For a parameter to function as a return parameter, it must be
declared as such within the stored procedure. The EXECUTE
statement or remote procedure call that calls the stored pro-
cedure must also indicate that the parameter should function as
a return parameter. In the case of a remote procedure call, it
is the dbrpcparam() routine that specifies whether a parameter
is a return parameter.
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o When executing a stored procedure, the server returns any
parameter values immediately after returning all other results.
Therefore, the application can call dbnumrets() only after pro-
cessing the stored procedure's results by calling dbresults(),
as well as dbnextrow() if appropriate. (Note that a stored
procedure can generate several sets of results-one for each
SELECT it contains. Before the application can call
dbnumrets() or any other routines that process return parame-
ters, it must call dbresults() and dbnextrow() as many times as
necessary to process all the results.)
o If the stored procedure is invoked with a remote procedure
call, the return parameter values are automatically available
to the application. If, on the other hand, the stored pro-
cedure is invoked with an EXECUTE statement, the return parame-
ter values are available only if the command batch containing
the EXECUTE statement uses local variables, not constants, for
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the return parameters.
o Other routines return additional information about return
parameter values:
o dbretdata() returns a pointer to a parameter value.
o dbretlen() returns the length of a parameter value.
o dbretname() returns the name of a parameter value.
o dbrettype() returns the datatype of a parameter value.
o For an example of this routine, see Example 8 in the DB-Library
Reference Supplement.
PARAMETERS:
dbproc - A pointer to the DBPROCESS structure that provides the
connection for a particular front-end/SQL Server process. It
contains all the information that DB-Library uses to manage
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communications and data between the front end and SQL Server.
RETURNS:
The number of return parameter values associated with the most
recently-executed stored procedure.
SEE ALSO:
dbnextrow, dbresults, dbretdata, dbretlen, dbretname, dbrettype,
dbrpcinit, dbrpcparam