T-SQL - TOP Clause
The T-SQL (Transact-SQL) TOP Clause is used to fetch specified number or percentage of records from a table. This is useful when the table contains thousands of records and returning a large dataset can impact performance.
Syntax
The syntax for using TOP Clause in T-SQL (Transact-SQL) is given below:
SELECT TOP number|percent column1, column2, ... FROM table_name WHERE condition(s);
Example:
Consider a database containing a table called Employee with the following records:
EmpID | Name | City | Age | Salary |
---|---|---|---|---|
1 | John | London | 25 | 3000 |
2 | Marry | New York | 24 | 2750 |
3 | Jo | Paris | 27 | 2800 |
4 | Kim | Amsterdam | 30 | 3100 |
5 | Ramesh | New Delhi | 28 | 3000 |
6 | Huang | Beijing | 28 | 2800 |
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To fetch top 3 records from the Employee table, the query is:
SELECT TOP 3 * FROM Employee;
This will produce the result as shown below:
EmpID Name City Age Salary 1 John London 25 3000 2 Marry New York 24 2750 3 Jo Paris 27 2800 -
The above result can also be achieved by using PERCENT keyword in the query.
SELECT TOP 50 PERCENT * FROM Employee;
This result of the following code will be:
EmpID Name City Age Salary 1 John London 25 3000 2 Marry New York 24 2750 3 Jo Paris 27 2800 -
To fetch top 3 records where the Age of the employee is greater than 25, the query will be:
SELECT TOP 3 * FROM Employee WHERE Age > 25;
This will produce the result as shown below:
EmpID Name City Age Salary 3 Jo Paris 27 2800 4 Kim Amsterdam 30 3100 5 Ramesh New Delhi 28 3000