SPI_execute_with_args — execute a command with out-of-line parameters
int SPI_execute_with_args(const char *command, intnargs, Oid *argtypes, Datum *values, const char *nulls, boolread_only, longcount)
SPI_execute_with_args executes a command that might
include references to externally supplied parameters. The command text
refers to a parameter as $, and
the call specifies data types and values for each such symbol.
nread_only and count have
the same interpretation as in SPI_execute.
The main advantage of this routine compared to
SPI_execute is that data values can be inserted
into the command without tedious quoting/escaping, and thus with much
less risk of SQL-injection attacks.
Similar results can be achieved with SPI_prepare followed by
SPI_execute_plan; however, when using this function
the query plan is always customized to the specific parameter values
provided.
For one-time query execution, this function should be preferred.
If the same command is to be executed with many different parameters,
either method might be faster, depending on the cost of re-planning
versus the benefit of custom plans.
const char * commandcommand string
int nargs number of input parameters ($1, $2, etc.)
Oid * argtypes an array of length nargs, containing the
OIDs of the data types of the parameters
Datum * values an array of length nargs, containing the actual
parameter values
const char * nulls an array of length nargs, describing which
parameters are null
If nulls is NULL then
SPI_execute_with_args assumes that no parameters
are null. Otherwise, each entry of the nulls
array should be ' ' if the corresponding parameter
value is non-null, or 'n' if the corresponding parameter
value is null. (In the latter case, the actual value in the
corresponding values entry doesn't matter.) Note
that nulls is not a text string, just an array:
it does not need a '\0' terminator.
bool read_onlytrue for read-only execution
long count maximum number of rows to return,
or 0 for no limit
The return value is the same as for SPI_execute.
SPI_processed and
SPI_tuptable are set as in
SPI_execute if successful.