Nombre
SPI_exec -- Creates an execution plan (parser+planner+optimizer) and executes a query.
Synopsis
Inputs
- char *query
String containing query plan
- int tcount
Maximum number of tuples to return
Outputs
- int
| SPI_OK_EXEC if properly disconnected |
| SPI_ERROR_UNCONNECTED if called from an un-connected procedure |
| SPI_ERROR_ARGUMENT if query is NULL or tcount < 0. |
| SPI_ERROR_UNCONNECTED if procedure is unconnected. |
| SPI_ERROR_COPY if COPY TO/FROM stdin. |
| SPI_ERROR_CURSOR if DECLARE/CLOSE CURSOR, FETCH. |
| SPI_ERROR_TRANSACTION if BEGIN/ABORT/END. |
| SPI_ERROR_OPUNKNOWN if type of query is unknown (this shouldn't occur). |
If execution of your query was successful then one of the following
(non-negative) values will be returned:
| SPI_OK_UTILITY if some utility (e.g. CREATE TABLE ...) was executed |
| SPI_OK_SELECT if SELECT (but not SELECT ... INTO!) was executed |
| SPI_OK_SELINTO if SELECT ... INTO was executed |
| SPI_OK_INSERT if INSERT (or INSERT ... SELECT) was executed |
| SPI_OK_DELETE if DELETE was executed |
| SPI_OK_UPDATE if UPDATE was executed |
Description
SPI_exec creates an execution plan (parser+planner+optimizer)
and executes the query for tcount tuples.
Usage
This should only be called from a connected procedure.
If tcount is zero then it executes the query for all tuples returned by the
query scan. Using tcount > 0 you may restrict the number of tuples for
which the query will be executed. For example,
SPI_exec ("insert into table select * from table", 5); |
will allow at most 5 tuples to be inserted into table.
If execution of your query was successful then a non-negative value will be returned.
 | You may pass many queries in one string or query string may be
re-written by RULEs. SPI_exec returns the result for the last query
executed. |
The actual number of tuples for which the (last) query was executed is
returned in the global variable SPI_processed (if not SPI_OK_UTILITY).
If SPI_OK_SELECT returned and SPI_processed > 0 then you may use global
pointer SPITupleTable *SPI_tuptable to access the selected tuples:
Also NOTE, that SPI_finish frees and makes all SPITupleTables
unusable! (See Memory management).
SPI_exec may return one of the following (negative) values:
| SPI_ERROR_ARGUMENT if query is NULL or tcount < 0. |
| SPI_ERROR_UNCONNECTED if procedure is unconnected. |
| SPI_ERROR_COPY if COPY TO/FROM stdin. |
| SPI_ERROR_CURSOR if DECLARE/CLOSE CURSOR, FETCH. |
| SPI_ERROR_TRANSACTION if BEGIN/ABORT/END. |
| SPI_ERROR_OPUNKNOWN if type of query is unknown (this shouldn't occur). |
Algorithm
SPI_exec performs the following:
- •
Disconnects your procedure from the SPI manager and frees all memory
allocations made by your procedure via palloc since the SPI_connect.
These allocations can't be used any more! See Memory management.