SPI_execute_with_args - Man Page

int SPI_execute_with_args(const char *command,
                          int nargs, Oid *argtypes,
                          Datum *values, const char *nulls,
                          bool read_only, long count)

SPI_execute_with_args executes a command that might include references to externally supplied parameters​. The command text refers to a parameter as $n, and the call specifies data types and values for each such symbol​. 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​.