SPI_execute_with_args — execute a command with out-of-line parameters
int SPI_execute_with_args(const char *command, intnargs, Oid *argtypes, const 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 andcount have the same interpretation as inSPI_execute.
The main advantage of this routine compared toSPI_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 withSPI_prepare followed bySPI_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
intnargsnumber of input parameters ($1,$2, etc.)
Oid *argtypesan array of lengthnargs, containing theOIDs of the data types of the parameters
Datum *valuesan array of lengthnargs, containing the actual parameter values
const char *nullsan array of lengthnargs, describing which parameters are null
Ifnulls isNULL thenSPI_execute_with_args assumes that no parameters are null. Otherwise, each entry of thenulls 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 correspondingvalues entry doesn't matter.) Note thatnulls is not a text string, just an array: it does not need a'\0' terminator.
boolread_onlytrue for read-only execution
longcountmaximum number of rows to return, or0 for no limit
The return value is the same as forSPI_execute.
SPI_processed andSPI_tuptable are set as inSPI_execute if successful.