Nowadays SQL is a very powerful language used to manage and manipulate relational databases. As you know that Operators in SQL play a very important role in performing operations on data within the databases
In this article, we will explain everything about operators in SQL, including its definition, and all different types of operators to enhance your skills for querying databases.
What are operators in SQL?
Operators in structured query language are symbols or keywords that are very important components of database queries and allow you to perform a wide range of tasks, filtering, and sorting data to perform arithmetic calculations, data comparisons, and logical evaluations. By using operators effectively, you can retrieve the exact information that you need.
Types of Operators in SQL
There are mainly 3 types of operators in structured query language, you can refer as follows –
- Arithmetic Operators
- Comparison Operators
- Logical Operators
Arithmetic Operators
Arithmetic operators are being used for mathematical calculations within the queries. These operators help you to perform computation on numeric data types, you can refer as follows –
- Addition (+)
- Subtraction (-)
- Multiplication (*)
- Division (/)
- Modulo (%)
Comparison Operators
Comparison operators are being used for making logical comparisons between values. These operators help you to retrieve data based on your specific criteria, you can refer as follows –
- Equal to (=)
- Greater than (>)
- Not Greater than (!>)
- Less than (<)
- Not Less than (!<)
- Not equal to (<> or !=)
- Greater than or equal to (>=)
- Less than or equal to (<=)
Logical Operators
Logical operators are being used to combine multiple conditions in queries. These operators help you to create complex conditions to retrieve the data as follows –
- AND
- OR
- NOT
- BETWEEN
- LIKE
- IN
- ALL
- ANY
- SOME
- EXISTS
- IS NULL
- IS NOT NULL
Common Mistakes to Avoid by Using Operators in SQL
Be aware of mistakes like incorrect syntax usage, improper operator combinations, or neglecting to handle NULL values. By familiarizing yourself with these potential pitfalls, you can sidestep errors and ensure the accuracy of your results.
Best Practices for Using Operators in SQL
Follow best practices such as optimizing queries, using indexes, and avoiding excessive data manipulation to ensure optimal performance. By adhering to these guidelines, you can extract insights from your data swiftly and effectively.
Practical Examples of Operators in SQL
Let’s explore practical examples of how operators are used in structured query language queries as follows –
Example 1: Arithmetic Operators (+, -, *, /, %)
SELECT Course_ID,(Course_ID+1) AS 'New_Course_ID', Course_Name, Student_ID FROM Wildcard_Course WHERE Course_ID = '2'
SELECT Course_ID,(Course_ID-1) AS 'New_Course_ID', Course_Name, Student_ID FROM Wildcard_Course WHERE Course_ID = '2'
SELECT Course_ID,(Course_ID*1) AS 'New_Course_ID', Course_Name, Student_ID FROM Wildcard_Course WHERE Course_ID = '2'
SELECT Course_ID,(Course_ID/1) AS 'New_Course_ID', Course_Name, Student_ID FROM Wildcard_Course WHERE Course_ID = '2'
SELECT Course_ID,(Course_ID%1) AS 'New_Course_ID', Course_Name, Student_ID FROM Wildcard_Course WHERE Course_ID = '2'
Example 2: Comparison Operators (=, >, !>, <, !<, <>, !=, >=, <=)
SELECT * FROM Wildcard_Course WHERE Course_ID = '2'
SELECT * FROM Wildcard_Course WHERE Course_ID > '2'
SELECT * FROM Wildcard_Course WHERE Course_ID !> '2'
SELECT * FROM Wildcard_Course WHERE Course_ID < '2' SELECT * FROM Wildcard_Course WHERE Course_ID !< '2' SELECT * FROM Wildcard_Course WHERE Course_ID <> '2'
SELECT * FROM Wildcard_Course WHERE Course_ID != '2'
SELECT * FROM Wildcard_Course WHERE Course_ID >= '2'
SELECT * FROM Wildcard_Course WHERE Course_ID <= '2'
Example 3: Logical Operators (AND, OR, NOT, BETWEEN, LIKE, IN, ALL, ANY, SOME, EXISTS, IS NULL, IS NOT NULL)
SELECT * FROM Wildcard_Course WHERE Course_ID BETWEEN '1' AND '3'
SELECT * FROM Wildcard_Course WHERE Course_ID = '2' OR Course_ID = '3'
SELECT * FROM Wildcard_Course WHERE Course_ID = '2' AND Course_Name NOT LIKE 'SQ%'
SELECT * FROM Wildcard_Course WHERE Course_ID BETWEEN '1' AND '3'
SELECT * FROM Wildcard_Course WHERE Course_Name LIKE 'SQ%'
SELECT * FROM Wildcard_Course WHERE Course_ID IN ( SELECT Course_ID FROM Wildcard_Course)
SELECT * FROM Wildcard_Course WHERE Course_ID> ALL ( SELECT Course_ID FROM Wildcard_Course)
SELECT * FROM Wildcard_Course WHERE Course_ID> ANY ( SELECT Course_ID FROM Wildcard_Course)
SELECT * FROM Wildcard_Course WHERE Course_ID< SOME ( SELECT Course_ID FROM Wildcard_Course)
SELECT * FROM Wildcard_Course WHERE EXISTS ( SELECT Course_ID FROM Wildcard_Course)
SELECT * FROM Wildcard_Course WHERE Course_Name IS NULL
SELECT * FROM Wildcard_Course WHERE Course_Name IS NOT NULL
FAQs
SQL, or Structured Query Language, is a domain-specific language used for managing and querying relational databases.
No, most SQL database systems are not case-sensitive when it comes to operators.
Absolutely! In fact, combining operators can help you create complex conditions and extract specific data subsets.
SQL operators are symbols or keywords used to perform various operations on data within a relational database.
Comparison operators, such as “=”, “<“, and “>”, are used to compare values and evaluate conditions in SQL queries.
Assignment operators, such as “+=” and “-=”, are used to update the values of variables or columns in SQL statements.
Conclusion
Operators are the backbone of SQL that provides you with a variety of powers of data manipulation and retrieval. You can use the full potential of SQL Server and enhance your data querying capabilities with the use of best practices of operators. We hope you like this very well.
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