TinyDB - The one_of() Query

For matching the subfield data, TinyDB provides a method called one_of(). This method searches a single category and gets at least one similar value. It will match if the field is contained in the provided list.

Syntax

The syntax of TinyDB one_of() is as follows −

db.search(Query().field.one_of(list)

Here, field represents the part of data that we want to access. Query() is the object created of our JSON table named student. It will fetch either single or multiple values of one category.

Let's understand how it works with the help of a couple examples. We will use the same student database that we have used in all the previous chapters.

Example 1

Let's see how we can find the fields from our student table where address is either "delhi" or "pune" −

from tinydb import TinyDB, Query
db = TinyDB('student.json')
db.search(Query().address.one_of(['delhi', 'pune']))

It will fetch all the rows where the "address" field contains either "delhi" or "pune".

[
   {
      "roll_number":1,
      "st_name":"elen",
      "mark":250,
      "subject":"TinyDB",
      "address":"delhi"
   },
   {
      "roll_number":2,
      "st_name":"Ram",
      "mark":[
         250,
         280
      ],
      "subject":[
         "TinyDB",
         "MySQL"
      ],
      "address":"delhi"
   }
]

Example 2

Let's see another example with 'subject' field −

from tinydb import TinyDB, Query
db = TinyDB('student.json')
db.search(Query().subject.one_of(['TinyDB', 'MySQL']))

It will fetch all the rows where the "subject" field contains either "TinyDB" or "MySQL".

[
   {
      "roll_number":1,
      "st_name":"elen",
      "mark":250,
      "subject":"TinyDB",
      "address":"delhi"
   },
   {
      "roll_number":4,
      "st_name":"lakhan",
      "mark":200,
      "subject":"MySQL",
      "address":"mumbai"
   },
   {
      "roll_number":5,
      "st_name":"karan",
      "mark":275,
      "subject":"TinyDB",
      "address":"benglore"
   }
]
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