SQLite

Definition of SQLite

SQLite is a process library that actualizes an independent, server-less, zero-setup, value-based SQL information base engine. Basically code in SQLite is a public space and it is free for any requirement such as business or private. SQLite database is widely deployed in the world with different types of applications. SQLite database does not use any separate server process, unlike other SQL databases. SQLite is an embedded SQL engine, so it directly performs the read and writes operation on the disk file. It has a complete SQL database that includes multiple tables, indices, triggers, and views. SQLite database is a cross-platform that means we can easily copy databases between 32 bit and 64 bit operating systems or different architectures.

Why do we need SQLite?

 SQLite is the most favorable database that can run almost anywhere. Normally SQLite we executed on different platforms such as Windows operating system, macOS, Linux, iOS, Android operating system, and then some. Windows clients specifically can utilize pre-compiled binary code for ordinary Win32, UWP, WinRT, and .Net. Whatever we need to implement that is targeted is for our application or software, so SQLite provides the facility to port the C source code into the target application.

Applications that utilization SQLite doesn’t need to be written in a specific language, as far as there is some approach to tie and work with outer libraries written in C. SQLite’s binary are independent, so they don’t require any specific sorcery to convey, so they can easily fall into a similar catalog or directory as the application.

Different languages use high-level binding for the SQLite database library and can utilize them to take access to other database layers for the language. The Python programming language, for example, packages the SQLite library as a standard component with the different Python interpreters. Moreover, outsiders have composed a wide assortment of ORMs and information layers that utilize SQLite, so you’re not stuck getting to SQLite through crude SQL strings. At long last, the source code of SQLite is public space, so it very well may be reused in different projects without any limitations.

Working of SQLite

Now let’s see the working of the SQLite database as follows. Basically, SQLite has the following parameters.

1. Interface

Every C program has an interface that is present in source file such as main.c and vdbeapi.c that means this file has access to the different data structure with the scope of file. Similarly, in SQLite we can find interfaces in sqlite3 get table() and that can be implemented in table.c and sqlite3 mprintf () we can find in printf.c.

So sometimes name collisions may occur, so to avoid that collision by using external symbols from SQLite library.

2. Tokenizer

When we find a SQL statement in the string, we first need to send this statement to the tokenizer, after that the tokenizer is divided into the different tokens and parsed them one by one.

3. Parser

After generating the token parser, assign the specific meaning to the token in their context. We can generate parsers in SQLite databases by using the Lemon parser generator. This parser works as same as YACC and BISON but different is in that it uses a different syntax.

4. Code Generator

This is the next parameter in SQLite that is a code generator, after parsing the token gather into the parse tree, so the code generator runs the parse tree and generates the bytecode that is helpful to execute the SQL statement. The code generator uses a different file such as attach. c, auth. c and build. c, etc. The where*.c is used to handle the select, update and delete statement. The delete.c, insert.c, select. c, and trigger. c is used for SQL statements with the same name.

5. Bytecode Engine

The bytecode is created by using the code generator and it runs into the virtual machine. The virtual machine contains the single source file that is vdbe. c and vdbe. h is header files that are helpful to define the interface between the virtual machine and SQLite library. There is different file are helps to virtual machines such as vdbe*.c file. SQLite implements the different SQL functions by using the C language routines at the same time we can implement some built-in SQL functions.

6. B-Tree

In SQLite database we need to maintain the disk so for that purpose, we use the B –tree and that found in the btree.c source file. Each table uses the different B – tree and all B- trees save on the same space that is the disk.

7. OS Interface

It provides portability across the different operating systems.

8. Utilities

Here we use the different utilities for different purposes such as memory allocation, text to number conversion and it is located in util. c.

9. Test Code

This code is only used for testing purposes and it is not included in the standard library.

Advantages and Disadvantages

Advantages:

1. It is a lightweight database.
2. It provides better performances than read and write operations.
3. There is no need for installation and configuration.
4. SQLite database is reliable, portable, and accessible.
5. It reduces the cost and complexity of the database.

Disadvantages:

1. It is used to handle the low and medium traffic over the HTTP request.
2. Here database size is limited to only 2 GB in most cases.
3. There is a single user database if we need to implement it for multi-users then an additional source is required.

Usage of SQLite

1. It is used for low-traffic websites because it is able to handle low to medium traffic.
2. SQLite database is used for data analysis.
3. Many software uses SQLite as a cache for similar content.
4. It is also used in server-side databases.

Career in SQLite

We have different Job opportunities in SQLite as follows.

1. Android Developer
2. Back End Developer
3. Data Analyst Engineer
4. Ios Developer etc

Conclusion

We hope from this article you have understood about SQLite. From this article, we see different career opportunities in SQLite. We also see what are the advantages and disadvantages of SQLite. From this article, we learned how and when we use SQLite.

Recommended Articles

This is a guide to SQLite. Here we discuss the definition, syntax, Why do we need SQLite? Working of SQLite and advantages and disadvantages. You may also have a look at the following articles to learn more –

1. SQL Clustered Index
2. SQL DATEDIFF()
3. SQL GROUP BY DAY
4. SQL LOCK TABLE