SPI_cursor_parse_open — set up a cursor using a query string and parameters
Portal SPI_cursor_parse_open(const char *name
, const char *command
, const SPIParseOpenOptions *options
)
SPI_cursor_parse_open
sets up a cursor
(internally, a portal) that will execute the specified query string.
This is comparable to SPI_prepare_cursor
followed
by SPI_cursor_open_with_paramlist
, except that
parameter references within the query string are handled entirely by
supplying a ParamListInfo
object.
For one-time query execution, this function should be preferred
over SPI_prepare_cursor
followed by
SPI_cursor_open_with_paramlist
.
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 options->params
object should normally
mark each parameter with the PARAM_FLAG_CONST
flag,
since a one-shot plan is always used for the query.
The passed-in parameter data will be copied into the cursor's portal, so it can be freed while the cursor still exists.
const char * name
name for portal, or NULL
to let the system
select a name
const char * command
command string
const SPIParseOpenOptions * options
struct containing optional arguments
Callers should always zero out the entire options
struct, then fill whichever fields they want to set. This ensures forward
compatibility of code, since any fields that are added to the struct in
future will be defined to behave backwards-compatibly if they are zero.
The currently available options
fields are:
ParamListInfo params
data structure containing query parameter types and values; NULL if none
int cursorOptions
integer bit mask of cursor options; zero produces default behavior
bool read_only
true
for read-only execution
Pointer to portal containing the cursor. Note there is no error
return convention; any error will be reported via elog
.