SPI_cursor_open_with_args

SPI_cursor_open_with_args — set up a cursor using a query and parameters

Synopsis

Portal SPI_cursor_open_with_args(const char *name,
                                 const char *command,
                                 int nargs, Oid *argtypes,
                                 Datum *values, const char *nulls,
                                 bool read_only, int cursorOptions)

Description

SPI_cursor_open_with_args sets up a cursor (internally, a portal) that will execute the specified query. Most of the parameters have the same meanings as the corresponding parameters to SPI_prepare_cursor and SPI_cursor_open.

For one-time query execution, this function should be preferred over SPI_prepare_cursor followed by SPI_cursor_open. 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.

The passed-in parameter data will be copied into the cursor's portal, so it can be freed while the cursor still exists.

Arguments

const char * name : name for portal, or NULL to let the system select a name

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_cursor_open_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

int cursorOptions : integer bit mask of cursor options; zero produces default behavior

Return Value

Pointer to portal containing the cursor. Note there is no error return convention; any error will be reported via elog.