SQLite

proc do_common_sql {sql} {
  execsql $sql db
  execsql $sql db2
}

proc changeset_from_sql {sql {dbname main}} {
  if {$dbname == "main"} {
    return [sql_exec_changeset db $sql]
  }
  set rc [catch {
    sqlite3session S db $dbname
    db eval "SELECT name FROM $dbname.sqlite_master WHERE type = 'table'" {
      S attach $name
    }
    db eval $sql
    S changeset

typedef struct TestStreamInput TestStreamInput;
struct TestStreamInput {
  int nStream;                    /* Maximum chunk size */
  unsigned char *aData;           /* Pointer to buffer containing data */
  int nData;                      /* Size of buffer aData in bytes */
  int iData;                      /* Bytes of data already read by sessions */
};

/*
** Extract an sqlite3* db handle from the object passed as the second
** argument. If successful, set *pDb to point to the db handle and return
** TCL_OK. Otherwise, return TCL_ERROR.
*/
static int dbHandleFromObj(Tcl_Interp *interp, Tcl_Obj *pObj, sqlite3 **pDb){
  Tcl_CmdInfo info;
  if( 0==Tcl_GetCommandInfo(interp, Tcl_GetString(pObj), &info) ){
    Tcl_AppendResult(interp, "no such handle: ", Tcl_GetString(pObj), 0);
    return TCL_ERROR;
  }

  *pDb = *(sqlite3 **)info.objClientData;
  return TCL_OK;
}

/*************************************************************************
** The following code is copied byte-for-byte from the sessions module
** documentation.  It is used by some of the sessions modules tests to
** ensure that the example in the documentation does actually work.
*/ 
/*
** Argument zSql points to a buffer containing an SQL script to execute 
** against the database handle passed as the first argument. As well as
** executing the SQL script, this function collects a changeset recording
** all changes made to the "main" database file. Assuming no error occurs,
** output variables (*ppChangeset) and (*pnChangeset) are set to point
** to a buffer containing the changeset and the size of the changeset in
** bytes before returning SQLITE_OK. In this case it is the responsibility
** of the caller to eventually free the changeset blob by passing it to
** the sqlite3_free function.
**
** Or, if an error does occur, return an SQLite error code. The final
** value of (*pChangeset) and (*pnChangeset) are undefined in this case.
*/
int sql_exec_changeset(
  sqlite3 *db,                  /* Database handle */
  const char *zSql,             /* SQL script to execute */
  int *pnChangeset,             /* OUT: Size of changeset blob in bytes */
  void **ppChangeset            /* OUT: Pointer to changeset blob */
){
  sqlite3_session *pSession = 0;
  int rc;

  /* Create a new session object */
  rc = sqlite3session_create(db, "main", &pSession);

  /* Configure the session object to record changes to all tables */
  if( rc==SQLITE_OK ) rc = sqlite3session_attach(pSession, NULL);

  /* Execute the SQL script */
  if( rc==SQLITE_OK ) rc = sqlite3_exec(db, zSql, 0, 0, 0);

  /* Collect the changeset */
  if( rc==SQLITE_OK ){
    rc = sqlite3session_changeset(pSession, pnChangeset, ppChangeset);
  }

  /* Delete the session object */
  sqlite3session_delete(pSession);

  return rc;
}
/************************************************************************/

/*
** Tclcmd: sql_exec_changeset DB SQL
*/
static int SQLITE_TCLAPI test_sql_exec_changeset(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  const char *zSql;
  sqlite3 *db;
  void *pChangeset;
  int nChangeset;
  int rc;

  if( objc!=3 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB SQL");
    return TCL_ERROR;
  }
  if( dbHandleFromObj(interp, objv[1], &db) ) return TCL_ERROR;
  zSql = (const char*)Tcl_GetString(objv[2]);

  rc = sql_exec_changeset(db, zSql, &nChangeset, &pChangeset);
  if( rc!=SQLITE_OK ){
    Tcl_ResetResult(interp);
    Tcl_AppendResult(interp, "error in sql_exec_changeset()", 0);
    return TCL_ERROR;
  }

  Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(pChangeset, nChangeset));
  sqlite3_free(pChangeset);
  return TCL_OK;
}



#define SESSION_STREAM_TCL_VAR "sqlite3session_streams"

/*
** Attempt to find the global variable zVar within interpreter interp
** and extract an integer value from it. Return this value.
**

    return test_session_error(interp, rc, 0);
  }

  return TCL_OK;
}

int TestSession_Init(Tcl_Interp *interp){
  struct Cmd {
    const char *zCmd;
    Tcl_ObjCmdProc *xProc;
  } aCmd[] = {
    { "sqlite3session", test_sqlite3session },

    { "sqlite3session_foreach", test_sqlite3session_foreach },


    { "sqlite3changeset_invert", test_sqlite3changeset_invert },


    { "sqlite3changeset_concat", test_sqlite3changeset_concat },


    { "sqlite3changeset_apply", test_sqlite3changeset_apply },


    { "sqlite3changeset_apply_replace_all", 
      test_sqlite3changeset_apply_replace_all },
    { "sql_exec_changeset", test_sql_exec_changeset },
  };
  int i;

  for(i=0; i<sizeof(aCmd)/sizeof(struct Cmd); i++){
    struct Cmd *p = &aCmd[i];
    Tcl_CreateObjCommand(interp, p->zCmd, p->xProc, 0, 0);
  }

  return TCL_OK;
}

#endif /* SQLITE_TEST && SQLITE_SESSION && SQLITE_PREUPDATE_HOOK */