SQLite

/*
** CAPI3REF: Name Of The Folder Holding Database Files
**
** ^(If this global variable is made to point to a string which is
** the name of a folder (a.k.a. directory), then all database files
** specified with a relative pathname and created or accessed by
** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
** to be relative to that directory.)^ ^If this variable is a NULL
** pointer, then SQLite assumes that all database files specified
** with a relative pathname are relative to the current directory
** for the process.  Only the windows VFS makes use of this global
** variable; it is ignored by the unix VFS.
**
** Changing the value of this variable while a database connection is
** open can result in a corrupt database.
**
** It is not safe to read or modify this variable in more than one
** thread at a time.  It is not safe to read or modify this variable
** if a [database connection] is being used at the same time in a separate

  pC = p->apCsr[pOp->p1];
  assert( pC->isSorter==0 );
  assert( pC->isTable || pOp->opcode!=OP_RowData );
  assert( pC->isIndex || pOp->opcode==OP_RowData );
  assert( pC!=0 );
  assert( pC->nullRow==0 );
  assert( pC->pseudoTableReg==0 );

  assert( pC->pCursor!=0 );
  pCrsr = pC->pCursor;
  assert( sqlite3BtreeCursorIsValid(pCrsr) );

  /* The OP_RowKey and OP_RowData opcodes always follow OP_NotExists or
  ** OP_Rewind/Op_Next with no intervening instructions that might invalidate
  ** the cursor.  Hence the following sqlite3VdbeCursorMoveto() call is always

  set DB [sqlite3_open_v2 file:test.db?vfs=nosuchvfs $flags ""]
  set errmsg [sqlite3_errmsg $DB]
  sqlite3_close $DB
  set errmsg
} {no such vfs: nosuchvfs}


# EVIDENCE-OF: R-44013-13102 The mode parameter may be set to either
# "ro", "rw", "rwc", or "memory". Attempting to set it to any other
# value is an error
#
sqlite3 db test.db
db close
foreach {tn uri error} "
  1    {file:test.db?mode=ro}    {not an error}
  2    {file:test.db?mode=rw}    {not an error}
  3    {file:test.db?mode=rwc}   {not an error}

    sqlite3 db $uri
    catchsql { INSERT INTO t1 VALUES(1, 2) }
  } $RES(w,$write)

  catch {db close}
}


# EVIDENCE-OF: R-20590-08726 It is an error to specify a value for the
# mode parameter that is less restrictive than that specified by the
# flags passed in the third parameter to sqlite3_open_v2().
#
forcedelete test.db
sqlite3 db test.db
db close
foreach {tn uri flags error} {
  1   {file:test.db?mode=ro}   ro    {not an error}
  2   {file:test.db?mode=ro}   rw    {not an error}