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The "Allow easy display of usernames in a group (pg_hba.conf uses groups

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now)" item on the open items, and subsequent plpgsql function I sent in,
made me realize it was too hard to get the upper and lower bound of an
array. The attached creates two functions that I think will be very
useful when combined with the ability of plpgsql to return sets.

array_lower(array, dim_num)
- and -
array_upper(array, dim_num)

They return the value (as an int) of the upper and lower bound of the
requested dim in the provided array.

Joe Conway
This commit is contained in:
Bruce Momjian
2002-11-08 17:27:03 +00:00
parent 7eb2b4b270
commit fef731d1c4
4 changed files with 70 additions and 5 deletions
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61
src/backend/utils/adt/arrayfuncs.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.81 2002/09/18 21:35:22 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.82 2002/11/08 17:27:02 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -866,6 +866,65 @@ array_dims(PG_FUNCTION_ARGS)
PG_RETURN_TEXT_P(result);
}
/*-----------------------------------------------------------------------------
* array_lower :
* returns the lower dimension, of the DIM requested, for
* the array pointed to by "v", as an int4
*----------------------------------------------------------------------------
*/
Datum
array_lower(PG_FUNCTION_ARGS)
{
ArrayType *v = PG_GETARG_ARRAYTYPE_P(0);
int reqdim = PG_GETARG_INT32(1);
int *lb;
int result;
/* Sanity check: does it look like an array at all? */
if (ARR_NDIM(v) <= 0 || ARR_NDIM(v) > MAXDIM)
PG_RETURN_NULL();
/* Sanity check: was the requested dim valid */
if (reqdim <= 0 || reqdim > ARR_NDIM(v))
PG_RETURN_NULL();
lb = ARR_LBOUND(v);
result = lb[reqdim - 1];
PG_RETURN_INT32(result);
}
/*-----------------------------------------------------------------------------
* array_upper :
* returns the upper dimension, of the DIM requested, for
* the array pointed to by "v", as an int4
*----------------------------------------------------------------------------
*/
Datum
array_upper(PG_FUNCTION_ARGS)
{
ArrayType *v = PG_GETARG_ARRAYTYPE_P(0);
int reqdim = PG_GETARG_INT32(1);
int *dimv,
*lb;
int result;
/* Sanity check: does it look like an array at all? */
if (ARR_NDIM(v) <= 0 || ARR_NDIM(v) > MAXDIM)
PG_RETURN_NULL();
/* Sanity check: was the requested dim valid */
if (reqdim <= 0 || reqdim > ARR_NDIM(v))
PG_RETURN_NULL();
lb = ARR_LBOUND(v);
dimv = ARR_DIMS(v);
result = dimv[reqdim - 1] + lb[reqdim - 1] - 1;
PG_RETURN_INT32(result);
}
/*---------------------------------------------------------------------------
* array_ref :
* This routine takes an array pointer and an index array and returns