Category: tinydb

TinyDB – Introduction ”; Previous Next What is TinyDB? TinyDB, written in pure Python programming language, is a small and lightweight document-orineted database with no external dependencies. It provides simple APIs that makes it easy to use. We can use TinyDB database for small project applications without any configuration. TinyDB module, available as a third-party module for Python programs, can be used to store, retereive, and modify the data in JSON format. Features of TinyDB TinyDB is a clean and hustle-free database to operate several formats of documents. It has the following features. Really tiny − TinyDB database is truly tiny in nature with only 1800 lines of code and 1600 lines tests. Easy to use − TinyDB is easy to use because of its simple and clean APIs. Document oriented − In TinyDB, we can store any document. The document will be represented as dict. Independent − The TinyDB database is independent of any external server and external dependencies from PyPI. Compatible with Python 3.6 or latest − TinyDB is tested and compatible with Python 3.6 and latest. It also works fine with PyPY3. Extensible − TinDB is easily extensible either by writing new storages or by modifying the behaviour of storages. Advantages of TinyDB TinyDB provide various benefits for students, users, and developers. TinyDB is open-sourced database aand it does not require any external configirations. It is quite easy-to-use, and the user can effortlessly handle documents. It automatically stores documents in the database. TinyDB is ideal in case of personal projects where we need to install some data. It is suitable for small applications that would be blown away by large databases like SQL or an external DB server. It uses a simple command line and query to operate data. There is 100% test coverage i.e., no explanation needed. Limitatations of TinyDB TinyDB will not be the right choice for your project if you need to − create indexes for tables, manage relationships between tables, use an HTTP server, or access from multiple processors. Comparison with Other Databases The following table highlights how TinyDB is different from MySQL and Oracle databases − Comparison Basis MySQL Oracle TinyDB Configurations Several Configurations Several Configurations Less Configurations, lightweight database Complicated Yes Yes No, easy-to-use and hustle-free Affordable No No Affordable than other databases Manageable Big database, hence difficult to manage Big database, hence difficult to manage Small and manageable Print Page Previous Next Advertisements ”;

TinyDB – Querying ”; Previous Next TinyDB has a rich set of queries. We have ways to construct queries: the first way resembles the syntax of ORM tools and the second is the traditional way of using the ”Where” clause. In this chapter, let”s understand these two ways of constructing a query in a TinyDB database. The First Method: Importing a Query The first method resembles the syntax of ORM tools in which first we need to import the query in the command prompt. After importing, we can use the query object to operate the TinyDB database. The syntax is given below − from tinydb import Query student = Query() Here, ”student” is the name of our database. For the examples, we will be using the following student database. [ { “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” }, { “roll_number”:3, “st_name”:”kevin”, “mark”:[ 180, 200 ], “subject”:[ “oracle”, “sql” ], “address”:”keral” }, { “roll_number”:4, “st_name”:”lakan”, “mark”:200, “subject”:”MySQL”, “address”:”mumbai” }, { “roll_number”:5, “st_name”:”karan”, “mark”:275, “subject”:”TinyDB”, “address”:”benglore” } ] Example Following is the query to retereive the data from the student database where the roll_no of the students are less than 3 − >>> db.search(Query().roll_number < 3) Or, >>> student = Query() >>> db.search(student.roll_number < 3) The above search query will produce the following result − [ { “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” } ] Sometimes the file name is not a valid Python identifier. In that case, we would not be able to access that field. For such cases, we need to switch to dict access notation as follows − student = Query(); # Invalid Python syntax db.search(student.security-code == ”ABCD”) # Use the following dict access notation db.search(student[”security-code”] == ”ABCD”) The Second Method: Using the “where” Clause The second way is the traditional way of constructing queries that uses the “where” clause. The syntax is given below − from tinydb import where db.search(where(”field”) == ”value”) Example TinyDB “where” clause for the subject field − db.search(where(”subject”) == ”MySQL”) The above query will produce the following output − [{ “roll_number”:4, “st_name”:”lakan”, “mark”:200, “subject”:”MySQL”, “address”:”mumbai” }] Print Page Previous Next Advertisements ”;

TinyDB Tutorial PDF Version Quick Guide Resources Job Search Discussion TinyDB is a lightweight database to operate various formats of the document. It is an easy and hustles free database to handle data of several applications. TinyDB is based on python code and supports clean API. This database does not need any coding language. It handles small projects without any configurations. Generally, a database can store, retrieve, and modify data in a JSON file. Audience TinyDB tutorial is helpful to learn from students to professionals in easy steps. This tutorial is designed for beginners to advance level developers for a web application. This tutorial makes you an intermediate or advanced level expert with practice. Prerequisites To learn this tutorial, you need to know about the Python version of your computer. You must know the working procedure of the command prompt. You do not need to learn coding language or install the software. Print Page Previous Next Advertisements ”;

TinyDB – Retrieve Data ”; Previous Next There are numerous ways with the help of which you can retrieve data from a TinyDB database. But to use those ways, you first need to create an instance of the Query class as follows − from tinydb import Query Student = Query() Here, Student is the name of the database. Let”s check the various ways to retrieve the information from a TinyDB database. Data Retrieval Using the Search() Method The search() method, as its name implies, returns the list of items that mathches the query we provided, otherwise it will return an empty list. For this and other examples, we will be using the following student database data − [ { “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” }, { “roll_number”: 3, “st_name”: “kevin”, “mark”: [ 180, 200 ], “subject”: [ “oracle”, “sql” ], “address”: “keral” }, { “roll_number”: 4, “st_name”: “lakan”, “mark”: 200, “subject”: “MySQL”, “address”: “mumbai” }, { “roll_number”: 5, “st_name”: “karan”, “mark”: 275, “subject”: “TinyDB”, “address”: “benglore” } ] Let”s take an example to understand the search() method − from tinydb import TinyDB, Query db = TinyDB(“leekha.json”) student = Query() db.search(student.subject == ”TinyDB” ) The above query will retrieve the the following output from the student database − [ { “roll_number”:1, “st_name”:”elen”, “mark”:250, “subject”:”TinyDB”, “address”:”delhi” }, { “roll_number”:5, “st_name”:”karan”, “mark”:275, “subject”:”TinyDB”, “address”:”benglore” } ] Data Retrieval Using the get() Method As opposed to the search() method, the get() method returns only one matching document. It will return None, otherwise. For example, let”s take the following code − from tinydb import TinyDB, Query student = Query() db.get(student.subject == ”TinyDB” ) The above query will retrieve the following data from the student database. [{”roll_number”: 1, ”st_name”: ”elen”, ”mark”: 250, ”subject”: ”TinyDB”, ”address”: ”delhi”}] Data Retrieval using the all() Method The all() method returns all the documents in the database. For example, db.all() It will retrieve the entire data from the student database. [ { “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” }, { “roll_number”:3, “st_name”:”kevin”, “mark”:[ 180, 200 ], “subject”:[ “oracle”, “sql” ], “address”:”keral” }, { “roll_number”:4, “st_name”:”lakan”, “mark”:200, “subject”:”MySQL”, “address”:”mumbai” }, { “roll_number”:5, “st_name”:”karan”, “mark”:275, “subject”:”TinyDB”, “address”:”benglore” } ] Data Retrieval Using the for Loop The for loop also returns all the documents in the database. For example, for info in db: print(info) Just like the all() method, it will retrieve all the rows from the student database. Print Page Previous Next Advertisements ”;