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. n
read_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 * command
command 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_only
true
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.