IndexedDB模糊搜索 [英] IndexedDB Fuzzy Search

问题描述

好的，首先，对不起我的英语。

Ok, first of all, sorry for my English.

我正在一个网络项目中工作，显示当我在输入框中输入内容时，但是我想要使用IndexedDB来提高Firefox中的查询速度。

I'm working in a web project that show suggests when I type something in the inputbox, but I want to use IndexedDB to improve the query speed in Firefox.

使用WebSQL我有这句话：

With WebSQL I have this sentence:

db.transaction(function (tx) {
  var SQL = 'SELECT "column1", 
                    "column2" 
             FROM "table"
             WHERE "column1" LIKE ?
             ORDER BY "sortcolumn" DESC
             LIMIT 6';

  tx.executeSql(SQL, [searchTerm + '%'], function(tx, rs) {
    // Process code here
  });
});

我想用IndexedDB做同样的事情，我有这个代码：

I want to do same thing with IndexedDB and I have this code:

db.transaction(['table'], 'readonly')
  .objectStore('table')
  .index('sortcolumn')
  .openCursor(null, 'prev')
  .onsuccess = function (e) {
    e || (e = event);
    var cursor = e.target.result;
    if (cursor) {
        if (cursor.value.column1.substr(0, searchTerm.length) == searchTerm) {
            // Process code here
        } else {
            cursor.continue();
        }
    }
};

但是太慢了，而且我的代码很麻烦..我想知道有没有更好的方法这样做。

But there's too slow and my code is buggy.. I want to know is there a better way to do this.

感谢回复。

推荐答案

我终于找到了这个问题的解决方案。

I finally found the solution to this problem.

解决方案包括在搜索词和搜索词之间用一个'z'字母限定一个键范围。示例：

The solution consist to bound a key range between the search term and the search term with a 'z' letter at the final. Example:

db.transaction(['table'], 'readonly')
  .objectStore('table')
  .openCursor(
    IDBKeyRange.bound(searchTerm, searchTerm + '\uffff'), // The important part, thank Velmont to point out
    'prev')
  .onsuccess = function (e) {
    e || (e = event);
    var cursor = e.target.result;
    if (cursor) {
      // console.log(cursor.value.column1 + ' = ' + cursor.value.column2);
      cursor.continue();
    }
  };

因为我需要订购结果，所以我在交易前定义了一个数组，然后我们称之为当我们加载所有数据时，如下所示：

Because I need to order the result, so I defined a array before the transaction, then we call it when we loaded all data, like this:

var result = [];
db.transaction(['table'], 'readonly')
  .objectStore('table')
  .openCursor(
    IDBKeyRange.bound(searchTerm, searchTerm + '\uffff'), // The important part, thank Velmont to point out
    'prev')
  .onsuccess = function (e) {
    e || (e = event);
    var cursor = e.target.result;
    if (cursor) {
      result.push([cursor.value.column1, cursor.value.sortcolumn]);
      cursor.continue();
    } else {
      if (result.length) {
        result.sort(function (a, b) {
          return a[1] - b[2];
        });
      }

      // Process code here
    }
  };

这篇关于IndexedDB模糊搜索的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！