javascript 范围IndexDB

Posted 2021-05-04

function searchItems(lower, upper) {
  if (lower === '' && upper === '') {return;}

  var range;
  if (lower !== '' && upper !== '') {
    range = IDBKeyRange.bound(lower, upper);
  } else if (lower === '') {
    range = IDBKeyRange.upperBound(upper);
  } else {
    range = IDBKeyRange.lowerBound(lower);
  }

  dbPromise.then(function(db) {
    var tx = db.transaction(['store'], 'readonly');
    var store = tx.objectStore('store');
    var index = store.index('price');
    return index.openCursor(range);
  }).then(function showRange(cursor) {
    if (!cursor) {return;}
    console.log('Cursored at:', cursor.key);
    for (var field in cursor.value) {
      console.log(cursor.value[field]);
    }
    return cursor.continue().then(showRange);
  }).then(function() {
    console.log('Done cursoring');
  });
}