WeChat small program cloud development API constructs the positive object

Db. Regexp

Starting with the underlying library 2.3.2 (wx-server-sdk starts at 0.0.23), the database supports regular expression queries, and developers can use JavaScript native regular objects or db. T he RegExp method constructs the positive object and then matches the string. A regular match to a field in a query condition requires that the value of the field be matched by a given regular expression, noting that regular expressions are not available within db.command, such as db.command.in.

Using regular expression matching is sufficient for string matching, but not for text matching/searching with long text/big data volumes, because there are performance issues and text search engines such as ElasticSearch should be used for such scenarios.

Db. RegExp is defined as follows:

function RegExp(initOptions: IInitOptions): DBRegExp

interface IInitOptions {
  regexp: string // 正则表达式，字符串形式
  options: string // flags，包括 i, m, s 但前端不做强限制
}

Options support the four flags i, m, s, note that JavaScript native positive objects are constructed with only two flags of i, m, so you must use db when using s this flag. T he RegExp constructor constructs a positive object. The meaning of flag can be found in the table below:

Examples of basic usage:

// 原生 JavaScript 对象
db.collection('todos').where({
  description: /miniprogram/i
})

// 数据库正则对象
db.collection('todos').where({
  description: db.RegExp({
    regexp: 'miniprogram',
    options: 'i',
  })
})

// 用 new 构造也是可以的
db.collection('todos').where({
  description: new db.RegExp({
    regexp: 'miniprogram',
    options: 'i',
  })
})