PostgreSQL Programmer's Guide
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# SPI_exec

## Name

SPI_exec — Creates an execution plan (parser+planner+optimizer) and executes a query.

    SPI_exec(query, tcount)

### 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.

> Note: 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.

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