Flashnux

GNU/Linux man pages

Livre :
Expressions régulières,
Syntaxe et mise en oeuvre :

ISBN : 978-2-7460-9712-4
EAN : 9782746097124
(Editions ENI)

GNU/Linux

CentOS 5.4

spi_cursor_open(7)


SPI_cursor_open

SPI_cursor_open

NAME
SYNOPSIS
DESCRIPTION
ARGUMENTS
RETURN VALUE

NAME

SPI_cursor_open − set up a cursor using a plan created with SPI_prepare

SYNOPSIS

Portal SPI_cursor_open(const char * name, void * plan,
Datum * values, const char * nulls,
bool read_only)

DESCRIPTION

SPI_cursor_open sets up a cursor (internally, a portal) that will execute a plan 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 plan 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.

ARGUMENTS

const char * name

name for portal, or NULL to let the system select a name

void * plan

execution plan (returned by SPI_prepare)

Datum * values

An array of actual parameter values. Must have same length as the plan’s number of arguments.

const char * nulls

An array describing which parameters are null. Must have same length as the plan’s number of arguments. n indicates a null value (entry in values will be ignored); a space indicates a nonnull value (entry in values is valid).

If nulls is NULL then SPI_cursor_open assumes that no parameters are null.

bool read_only

true for read-only execution

RETURN VALUE

pointer to portal containing the cursor, or NULL on error



spi_cursor_open(7)