@ -1,87 +1,47 @@
/*-------------------------------------------------------------------------
*
* params . h
* Declarations of stuff needed to handle parameterized plan s.
* Support for finding the values associated with Param node s.
*
*
* Portions Copyright ( c ) 1996 - 2006 , PostgreSQL Global Development Group
* Portions Copyright ( c ) 1994 , Regents of the University of California
*
* $ PostgreSQL : pgsql / src / include / nodes / params . h , v 1.30 2006 / 03 / 05 15 : 58 : 56 momjian Exp $
* $ PostgreSQL : pgsql / src / include / nodes / params . h , v 1.31 2006 / 04 / 22 01 : 26 : 01 tgl Exp $
*
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
*/
# ifndef PARAMS_H
# define PARAMS_H
# include "access/attnum.h"
/* ----------------
* The following are the possible values for the ' paramkind '
* field of a Param node .
*
* PARAM_NAMED : The parameter has a name , i . e . something
* like ` $ . salary ' or ` $ . foobar ' .
* In this case field ` paramname ' must be a valid name .
*
* PARAM_NUM : The parameter has only a numeric identifier ,
* i . e . something like ` $ 1 ' , ` $ 2 ' etc .
* The number is contained in the ` paramid ' field .
*
* PARAM_EXEC : The parameter is an internal executor parameter .
* It has a number contained in the ` paramid ' field .
*
* PARAM_SUBLINK : The parameter represents an output column of a SubLink
* node ' s sub - select . The column number is contained in the
* ` paramid ' field . ( This type of Param is converted to
* PARAM_EXEC during planning . )
*
* PARAM_INVALID should never appear in a Param node ; it ' s used to mark
* the end of a ParamListInfo array .
*
* NOTE : As of PostgreSQL 7.3 , named parameters aren ' t actually used and
* so the code that handles PARAM_NAMED cases is dead code . We leave it
* in place since it might be resurrected someday .
* - - - - - - - - - - - - - - - -
*/
# define PARAM_NAMED 11
# define PARAM_NUM 12
# define PARAM_EXEC 15
# define PARAM_SUBLINK 16
# define PARAM_INVALID 100
/* ----------------
* ParamListInfo
*
* ParamListInfo entrie sare used to pass parameters into the executor
* ParamListInfo arrays are used to pass parameters into the executor
* for parameterized plans . Each entry in the array defines the value
* to be substituted for a PARAM_NAMED or PARAM_NUM parameter .
* to be substituted for a PARAM_EXTERN parameter . The " paramid "
* of a PARAM_EXTERN Param can range from 1 to numParams .
*
* kind : the kind of parameter ( PARAM_NAMED or PARAM_NUM )
* name : the parameter name ( valid if kind = = PARAM_NAMED )
* id : the parameter id ( valid if kind = = PARAM_NUM )
* ptype : the type of the parameter value
* isnull : true if the value is null ( if so ' value ' is undefined )
* value : the value that has to be substituted in the place
* of the parameter .
* Although parameter numbers are normally consecutive , we allow
* ptype = = InvalidOid to signal an unused array entry .
*
* ParamListInfo is to be used as an array of ParamListInfoData
* records . A dummy record with kind = = PARAM_INVALID marks the end
* of the array .
* Although the data structure is really an array , not a list , we keep
* the old typedef name to avoid unnecessary code changes .
* - - - - - - - - - - - - - - - -
*/
typedef struct ParamExternData
{
Datum value ; /* parameter value */
bool isnull ; /* is it NULL? */
Oid ptype ; /* parameter's datatype, or 0 */
} ParamExternData ;
typedef struct ParamListInfoData
{
int kind ;
char * name ;
AttrNumber id ;
Oid ptype ;
bool isnull ;
Datum value ;
int numParams ; /* number of ParamExternDatas following */
ParamExternData params [ 1 ] ; /* VARIABLE LENGTH ARRAY */
} ParamListInfoData ;
typedef ParamListInfoData * ParamListInfo ;
@ -114,8 +74,5 @@ typedef struct ParamExecData
/* Functions found in src/backend/nodes/params.c */
extern ParamListInfo copyParamList ( ParamListInfo from ) ;
extern ParamListInfo lookupParam ( ParamListInfo paramList , int thisParamKind ,
const char * thisParamName , AttrNumber thisParamId ,
bool noError ) ;
# endif /* PARAMS_H */
Tom Lane
20 years ago