granicus.if.org Git - postgresql/blob - src/include/commands/prepare.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * prepare.h
   4  *        PREPARE, EXECUTE and DEALLOCATE commands, and prepared-stmt storage
   5  *
   6  *
   7  * Copyright (c) 2002-2007, PostgreSQL Global Development Group
   8  *
   9  * $PostgreSQL: pgsql/src/include/commands/prepare.h,v 1.23 2007/01/05 22:19:53 momjian Exp $
  10  *
  11  *-------------------------------------------------------------------------
  12  */
  13 #ifndef PREPARE_H
  14 #define PREPARE_H
  15
  16 #include "executor/executor.h"
  17 #include "utils/timestamp.h"
  18
  19 /*
  20  * The data structure representing a prepared statement
  21  *
  22  * Note: all subsidiary storage lives in the context denoted by the context
  23  * field.  However, the string referenced by commandTag is not subsidiary
  24  * storage; it is assumed to be a compile-time-constant string.  As with
  25  * portals, commandTag shall be NULL if and only if the original query string
  26  * (before rewriting) was an empty string.
  27  */
  28 typedef struct
  29 {
  30         /* dynahash.c requires key to be first field */
  31         char            stmt_name[NAMEDATALEN];
  32         char       *query_string;       /* text of query, or NULL */
  33         const char *commandTag;         /* command tag (a constant!), or NULL */
  34         List       *query_list;         /* list of queries, rewritten */
  35         List       *plan_list;          /* list of plans */
  36         List       *argtype_list;       /* list of parameter type OIDs */
  37         TimestampTz prepare_time;       /* the time when the stmt was prepared */
  38         bool            from_sql;               /* stmt prepared via SQL, not FE/BE protocol? */
  39         MemoryContext context;          /* context containing this query */
  40 } PreparedStatement;
  41
  42
  43 /* Utility statements PREPARE, EXECUTE, DEALLOCATE, EXPLAIN EXECUTE */
  44 extern void PrepareQuery(PrepareStmt *stmt);
  45 extern void ExecuteQuery(ExecuteStmt *stmt, ParamListInfo params,
  46                          DestReceiver *dest, char *completionTag);
  47 extern void DeallocateQuery(DeallocateStmt *stmt);
  48 extern void ExplainExecuteQuery(ExplainStmt *stmt, ParamListInfo params,
  49                                         TupOutputState *tstate);
  50
  51 /* Low-level access to stored prepared statements */
  52 extern void StorePreparedStatement(const char *stmt_name,
  53                                            const char *query_string,
  54                                            const char *commandTag,
  55                                            List *query_list,
  56                                            List *plan_list,
  57                                            List *argtype_list,
  58                                            bool from_sql);
  59 extern PreparedStatement *FetchPreparedStatement(const char *stmt_name,
  60                                            bool throwError);
  61 extern void DropPreparedStatement(const char *stmt_name, bool showError);
  62 extern List *FetchPreparedStatementParams(const char *stmt_name);
  63 extern TupleDesc FetchPreparedStatementResultDesc(PreparedStatement *stmt);
  64 extern bool PreparedStatementReturnsTuples(PreparedStatement *stmt);
  65 extern List *FetchPreparedStatementTargetList(PreparedStatement *stmt);
  66
  67 #endif   /* PREPARE_H */