Add the sqlite_open_aux_file() API. (CVS 646)

FossilOrigin-Name: 332164d6455658ca633a1dc49811d9fb0fd4b01c

4 files changed, 103 insertions, 13 deletions

diff --git a/src/main.c b/src/main.c
index e6877b38f..ee79bfdb9 100644
--- a/src/main.c
+++ b/src/main.c
@@ -14,7 +14,7 @@
 ** other files are for internal use by SQLite and should not be
 ** accessed by users of the library.
 **
-** $Id: main.c,v 1.84 2002/06/25 01:09:11 drh Exp $
+** $Id: main.c,v 1.85 2002/06/25 19:31:18 drh Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -710,7 +710,9 @@ int sqlite_create_aggregate(
 }
 
 /*
-** Change the datatype for all functions with a given name.
+** Change the datatype for all functions with a given name.  See the
+** header comment for the prototype of this function in sqlite.h for
+** additional information.
 */
 int sqlite_function_type(sqlite *db, const char *zName, int dataType){
   FuncDef *p = (FuncDef*)sqliteHashFind(&db->aFunc, zName, strlen(zName));
@@ -720,3 +722,43 @@ int sqlite_function_type(sqlite *db, const char *zName, int dataType){
   }
   return SQLITE_OK;
 }
+
+/*
+** Attempt to open the file named in the argument as the auxiliary database
+** file.  The auxiliary database file is used to store TEMP tables.  But
+** by using this API, it is possible to trick SQLite into opening two
+** separate databases and acting on them as if they were one.
+**
+** This routine closes the existing auxiliary database file, which will
+** cause any previously created TEMP tables to be created.
+**
+** The zName parameter can be a NULL pointer or an empty string to cause
+** a temporary file to be opened and automatically deleted when closed.
+*/
+int sqlite_open_aux_file(sqlite *db, const char *zName, char **pzErrMsg){
+  int rc;
+  if( zName && zName[0]==0 ) zName = 0;
+  if( sqliteSafetyOn(db) ) goto openaux_misuse;
+  sqliteResetInternalSchema(db);
+  if( db->pBeTemp!=0 ){
+    sqliteBtreeClose(db->pBeTemp);
+  }
+  rc = sqliteBtreeOpen(zName, 0, MAX_PAGES, &db->pBeTemp);
+  if( rc ){
+    if( zName==0 ) zName = "a temporary file";
+    sqliteSetString(pzErrMsg, "unable to open ", zName, 
+      ": ", sqlite_error_string(rc), 0);
+    sqliteStrRealloc(pzErrMsg);
+    sqliteSafetyOff(db);
+    return rc;
+  }
+  rc = sqliteInit(db, pzErrMsg);
+  if( sqliteSafetyOff(db) ) goto openaux_misuse;
+  sqliteStrRealloc(pzErrMsg);
+  return rc;
+
+openaux_misuse:
+  sqliteSetString(pzErrMsg, sqlite_error_string(SQLITE_MISUSE), 0);
+  sqliteStrRealloc(pzErrMsg);
+  return SQLITE_MISUSE;
+}
diff --git a/src/shell.c b/src/shell.c
index d8ee2108e..a3c94bf67 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -12,7 +12,7 @@
 ** This file contains code to implement the "sqlite" command line
 ** utility for accessing SQLite databases.
 **
-** $Id: shell.c,v 1.58 2002/06/25 01:09:12 drh Exp $
+** $Id: shell.c,v 1.59 2002/06/25 19:31:18 drh Exp $
 */
 #include <stdlib.h>
 #include <string.h>
@@ -486,6 +486,7 @@ static char zHelp[] =
   "                       \"insert\", \"list\", or \"html\"\n"
   ".mode insert TABLE     Generate SQL insert statements for TABLE\n"
   ".nullvalue STRING      Print STRING instead of nothing for NULL data\n"
+  ".openaux FILENAME      Use FILENAME to hold TEMP tables\n"
   ".output FILENAME       Send output to FILENAME\n"
   ".output stdout         Send output to the screen\n"
   ".prompt MAIN CONTINUE  Replace the standard prompts\n"
@@ -702,6 +703,15 @@ static int do_meta_command(char *zLine, sqlite *db, struct callback_data *p){
     sprintf(p->nullvalue, "%.*s", (int)ArraySize(p->nullvalue)-1, azArg[1]);
   }else
 
+  if( c=='o' && strncmp(azArg[0], "openaux", n)==0 ){
+    char *zErrMsg = 0;
+    sqlite_open_aux_file(db, nArg>=2 ? azArg[1] : 0, &zErrMsg);
+    if( zErrMsg ){
+      fprintf(stderr,"Error: %s\n", zErrMsg);
+      free(zErrMsg);
+    }
+  }else
+
   if( c=='o' && strncmp(azArg[0], "output", n)==0 && nArg==2 ){
     if( p->out!=stdout ){
       fclose(p->out);
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index 5d7d52c1f..f14e06ff4 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -12,7 +12,7 @@
 ** This header file defines the interface that the SQLite library
 ** presents to client programs.
 **
-** @(#) $Id: sqlite.h.in,v 1.32 2002/06/20 11:36:50 drh Exp $
+** @(#) $Id: sqlite.h.in,v 1.33 2002/06/25 19:31:18 drh Exp $
 */
 #ifndef _SQLITE_H_
 #define _SQLITE_H_
@@ -496,6 +496,14 @@ void *sqlite_aggregate_context(sqlite_func*, int nBytes);
 */
 int sqlite_aggregate_count(sqlite_func*);
 
+/*
+** Attempt to open the file named in the argument as the auxiliary database
+** file.  The auxiliary database file is used to store TEMP tables.  But
+** by using this API, it is possible to trick SQLite into opening two
+** separate databases and acting on them as if they were one.
+*/
+int sqlite_open_aux_file(sqlite *db, const char *zName, char **pzErrMsg);
+
 #ifdef __cplusplus
 }  /* End of the 'extern "C"' block */
 #endif
diff --git a/src/tclsqlite.c b/src/tclsqlite.c
index 7df3f7741..c613e8a60 100644
--- a/src/tclsqlite.c
+++ b/src/tclsqlite.c
@@ -11,7 +11,7 @@
 *************************************************************************
 ** A TCL Interface to SQLite
 **
-** $Id: tclsqlite.c,v 1.32 2002/05/10 13:14:07 drh Exp $
+** $Id: tclsqlite.c,v 1.33 2002/06/25 19:31:18 drh Exp $
 */
 #ifndef NO_TCL     /* Omit this whole file if TCL is unavailable */
 
@@ -267,24 +267,26 @@ static int DbBusyHandler(void *cd, const char *zTable, int nTries){
 static int DbObjCmd(void *cd, Tcl_Interp *interp, int objc,Tcl_Obj *const*objv){
   SqliteDb *pDb = (SqliteDb*)cd;
   int choice;
-  static char *DB_optStrs[] = {
-     "busy",  "changes",            "close",    "complete", 
-     "eval",  "last_insert_rowid",  "timeout",  0
+  static char *DB_strs[] = {
+    "busy",               "changes",           "close",
+    "complete",           "eval",              "last_insert_rowid",
+    "open_aux_file",      "timeout",           0
   };
-  enum DB_opts {
-     DB_BUSY, DB_CHANGES,           DB_CLOSE,   DB_COMPLETE,
-     DB_EVAL, DB_LAST_INSERT_ROWID, DB_TIMEOUT
+  enum DB_enum {
+    DB_BUSY,              DB_CHANGES,          DB_CLOSE,
+    DB_COMPLETE,          DB_EVAL,             DB_LAST_INSERT_ROWID,
+    DB_OPEN_AUX_FILE,     DB_TIMEOUT,          
   };
 
   if( objc<2 ){
     Tcl_WrongNumArgs(interp, 1, objv, "SUBCOMMAND ...");
     return TCL_ERROR;
   }
-  if( Tcl_GetIndexFromObj(interp, objv[1], DB_optStrs, "option", 0, &choice) ){
+  if( Tcl_GetIndexFromObj(interp, objv[1], DB_strs, "option", 0, &choice) ){
     return TCL_ERROR;
   }
 
-  switch( (enum DB_opts)choice ){
+  switch( (enum DB_enum)choice ){
 
   /*    $db busy ?CALLBACK?
   **
@@ -464,6 +466,34 @@ static int DbObjCmd(void *cd, Tcl_Interp *interp, int objc,Tcl_Obj *const*objv){
   }
 
   /*
+  **     $db open_aux_file  FILENAME
+  **
+  ** Begin using FILENAME as the database file used to store temporary
+  ** tables.
+  */
+  case DB_OPEN_AUX_FILE: {
+    const char *zFilename;
+    char *zErrMsg = 0;
+    int rc;
+    if( objc!=3 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "FILENAME");
+      return TCL_ERROR;
+    }
+    zFilename = Tcl_GetStringFromObj(objv[2], 0);
+    rc = sqlite_open_aux_file(pDb->db, zFilename, &zErrMsg);
+    if( rc!=0 ){
+      if( zErrMsg ){
+        Tcl_AppendResult(interp, zErrMsg, 0);
+        free(zErrMsg);
+      }else{
+        Tcl_AppendResult(interp, sqlite_error_string(rc), 0);
+      }
+      return TCL_ERROR;
+    }
+    break;
+  }
+
+  /*
   **     $db timeout MILLESECONDS
   **
   ** Delay for the number of milliseconds specified when a file is locked.