In This Article You Will Know About SQL WHERE Clause.
SQL WHERE Clause – Before moving ahead, let’s know a bit about Top Python Skills.
Table of Contents
SQL WHERE Clause
The SQL Where clause is used to get the records from the section (column-row) where the specified condition is specified.
WHERE Syntax:
SELECT column1, column2, ...
FROM table_name
WHERE condition;
Note: The WHERE clause is not used only in the SELECT clause but also used in other SQL clauses such as UPDATE, DELETE, etc.
Example Database
Below is the example of a database table named “details”.
Id | Name | class | section_id |
1 | Alex | 5 | 1 |
2 | Rolex | 6 | 2 |
3 | Salex | 7 | 2 |
4 | Lelex | 8 | 3 |
5 | Kelex | 9 | 5 |
WHERE – SELECT *
Example: Use WHERE clause to return the records after matching specified conditions.
SELECT * FROM details
WHERE section_id = 2;
WHERE – SELECT FROM specified column
Example: Use WHERE clause to return the records after matching specified conditions.
SELECT class
FROM details
WHERE name = 'Lelex';
WHERE Operator
WHERE – Greater than operator
Example: Use WHERE clause to return the records after matching specified conditions.
SELECT * FROM details
WHERE section_id > 2;
WHERE – Less than operator
Example: Use WHERE clause to return the records after matching specified conditions.
SELECT * FROM details
WHERE section_id < 5;
WHERE – Greater than or equal operator
Example: Use WHERE clause to return the records after matching specified conditions.
SELECT * FROM details
WHERE section_id >= 3;
WHERE – Less than or equal operator
Example: Use WHERE clause to return the records after matching specified conditions.
SELECT * FROM details
WHERE section_id <= 5;
WHERE – Not equal operator
Example: Use WHERE clause to return the records after matching specified conditions.
SELECT * FROM details
WHERE section_id <> 3;
Note: In some SQL version, not equal operator is defined as != too.
WHERE – BETWEEN operator
Search for a certain range.
Example: Use WHERE clause to return the records after matching specified conditions.
SELECT * FROM details
WHERE section_id BETWEEN 2 AND 5;
Note: You will learn later about SQL AND clause.
WHERE – LIKE operator
Search for a pattern.
Example: Use WHERE clause to return the records after matching specified conditions.
SELECT * FROM details
WHERE name LIKE '%x';
Note: You will learn later about SQL AND clause.
WHERE – IN operator
Search between multiple conditions.
Example: Use WHERE clause to return the records after matching specified conditions.
SELECT * FROM details
WHERE section_id IN (2, 5);
