We elaborate that what is the difference between sql and hql? In detail with definition and in-tabular form to better understand the concept. Lets Read….
What is SQL?
SQL, often referred to as ‘sequel’ or ‘SQL’, is a database query language used to process RDBMS data. SQL is not an OOP (Object Oriented Programming Language), but directly generates queries and sends data retrieval requests from RDBM. It operates on tables and columns where data is stored and handles all operations in RDBMS.
It is used as a standard database query language in almost all RDBMS like MySql, Oracle, MsAccess, etc. The standard SQL commands that are used to interact with relational databases are SELECT, CREATE, DELETE, INSERT, UPDATE, and DROP.
Unlike other programming languages, SQL cannot be used to develop standalone programs and can only be operated within RDBMS. It is a declarative type of language, that is, it tells the database what to do and lets the RDBMS decide the details of the implementation (how it should be done)
Its advantage is that the user is not required to write a substantial amount of code, but users only have partial control over the databases due to hidden business rules, and it also has a rather complex interface.
What is HQL?
HQL or Hibernate Query Language is an object-oriented query programming language that is written embedded in JAVA code and uses various functions in JAVA library to convert entity codes into traditional query codes that can interact with databases .
This conversion function is performed by a JAVA framework called ‘Hibernate’ from which HQL derives its name. The meaning of hibernation is spending a particular period of time in a sleep / inactive state. Similarly, the ‘hibernate’ feature remains active only behind the app.
It is an ORM (Object Relational Mapping) -based framework that transfers data between an application and a relational database in the form of objects. HQL works with classes and their properties that are finally mapped to the table structure within the corresponding database.
HQL is very useful if a programmer knows the object-oriented programming language and wants to interact with databases, where he can do so without having to learn the traditional SQL query language.
Although HQL is very easy to use, it is usually slower than SQL since its execution time is based on mapping. Also, it is not suitable for small projects involving fewer tables, as the introduction of the entire hibernate framework becomes difficult.
Data is a collection of raw statistical or factual information in any form over a network. Data processing converts it into information that is then very useful. Related data is organized in databases (both hardware and software) for easy administration. DBMS (Database Management System) is a software that allows the user to create and manipulate databases.
To request and extract data from a database by submitting queries, we use QL (Query Language). Structured Query Language ( SQL ) and Hibernate Query Language ( HQL ) are used to retrieve data from RDBMS (Relational DBMS) which stores data in tabular form.
In our day to day, query languages play a vital role in providing the foundation for various interfaces such as ATM, web pages, online order processing, accounting, insurance records, etc.
The difference between SQL and HQL is that SQL works directly on databases through queries, while HQL operates on objects and their properties, which are then translated into conventional queries to execute databases.
Comparison table between SQL and HQL
|Full form||Stands for structured query language||It stands for Hibernate Query Language|
|Type of programming language||Traditional query language||JAVA-based OOP query language|
|Concerns||It belongs to the relationship between two tables or columns.||The relationship between two objects belongs to two|
|Ease of use||Offers a complex interface for new users||Provides an easy to use interface.|
|Characteristics||Use tables and columns||Use JAVA classes and variables|
|Interaction with the database||Interact directly with the database||Use the ‘Hibernate’ interface to interact with the database|
|Speed||Native SQL is usually faster||Non-native HQL is usually slower as its execution time is based on mapping, but its speed can be increased by setting the correct cache size of the query plan|
Main differences between SQL and HQL
- SQL is a traditional query language that interacts directly with RDBM, while HQL is a JAVA-based OOP language that uses the Hibernate interface to convert OOP code into query statements and then interacts with databases.
- SQL is based solely on RDBMS, but HQL is a combination of OOP with relational databases.
- SQL deals with the relationship between two tables or columns, while HQL deals with the relationship between two objects.
- A user who does not know QL but has an idea about OOP language like JAVA can interact with databases using HQL but not SQL.
- SQL does not support object-oriented programming functions such as polymorphism, inheritance, and association, but HQL does.
- SQL has a complex interface compared to the easy-to-use OOP interface that HQL is based on.
- Both SQL and HQL use the same set of keywords, but SQL uses tables and columns in contrast to HQL, which uses JAVA classes and properties.
- Traditional SQL code is longer than HQL code.
- SQL is usually faster than non-native HQL; however, by setting the correct cache size of the query plan, you can make HQL work as fast as SQL.
The main objective of SQL and HQL, or rather of any query language, is to allow the user to extract data from databases and information systems.
SQL is different from other programming languages in that it only works within a database management system and cannot create standalone programs, whereas this is not the case with HQL.
A user who is new to QL and wants to interact with RDBMS and expose himself to a native query language should preferably opt for SQL, as it is traditional and fast. On the other hand, a user who has coding experience in an object-oriented programming language should opt for HQL, as it has a more user-friendly interface with object-oriented programming features.