SPI_cursor_parse_open
SPI_cursor_parse_open — set up a cursor using a query string and parameters
Synopsis
Portal SPI_cursor_parse_open(const char *name
, const char *command
, const SPIParseOpenOptions *options
)
Description
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.
Arguments
const char *
name
name for portal, or
NULL
to let the system select a nameconst 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
Return Value
Pointer to portal containing the cursor. Note there is no error return convention; any error will be reported via elog
.