NAME¶

SPI_cursor_open - set up a cursor using a statement created with SPI_prepare

SYNOPSIS¶

Portal SPI_cursor_open(const char * name, SPIPlanPtr plan,


                       Datum * values, const char * nulls,


                       bool read_only)

DESCRIPTION¶

SPI_cursor_open sets up a cursor (internally, a portal) that will execute a statement prepared by SPI_prepare. The parameters have the same meanings as the corresponding parameters to SPI_execute_plan.

Using a cursor instead of executing the statement directly has two benefits. First, the result rows can be retrieved a few at a time, avoiding memory overrun for queries that return many rows. Second, a portal can outlive the current procedure (it can, in fact, live to the end of the current transaction). Returning the portal name to the procedure's caller provides a way of returning a row set as result.

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

SPIPlanPtr plan

Datum * values

const char * nulls

bool read_only

RETURN VALUE¶

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