What is DQL?
DQL stands for Data Query Language. It is a type of SQL sub-language. These statements are used to select rows from a table or join tables together to retrieve data from multiple tables in a query. The most common DQL statement is the SELECT statement.
When
When to use DQL statements?
We use the DQL statement when we retrieve the data from a database. The benefits of this statement are:
Where
Where do we use DQL?
DQL can be used in a variety of places, including:
Who
Who created DQL?
Donald D. Chamberlin and Raymond F. Boyce created DQL (Data Query Language) in the early 1970s
Why
Why is the SELECT statement the most common DQL statement?
The SELECT statement is the most common DQL statement because it is used to select rows from a table. The SELECT statement can be used to specify which columns to return, as well as any conditions that must be met for a row to be selected. This makes the SELECT statement very versatile and useful for a wide variety of tasks.
For example, the SELECT statement can be used to:
The SELECT statement is also very efficient and can retrieve data quickly. This makes it the ideal choice for most data retrieval tasks.
How
How DQL differs from DDL?
DQL or Data Query Language is used to query data from a database. It is a subset of SQL and is used to select, insert, update, and delete data from a database.
DDL or Data Definition Language is used to define the structure of a database. It is used to create, alter, and drop tables, columns, and other database objects.
The main difference between DQL and DDL is that DQL is used to manipulate data, while DDL is used to manipulate the structure of a database.
How many
How many different kinds of statements are there in DQL?
There are four different kinds of statements in DQL: