SQL SELECT TOP statement overview and examples
Note − By default, the ORDER BY clause sorts the data in ascending order. So, if we need to sort the data in descending order, we must use the DESC keyword. From the above-mentioned parameters, TOP NUMBER OR PERCENT, Column_names and FROM tables are compulsory. We can also use other SQL keywords, such as JOIN, having, etc. in the given syntax. Enter your query below, and we’ll provide instant results tailored to your needs.
It can also be useful if you’re developing queries where you’re
only interested in the query’s logic as you’re developing them instead
of returning all the data. TOP is usually used with the ORDER BY clause, as the
order of the data is not guaranteed unless specified. TOP and ORDER BY basic database queries can be used
together to return the highest or lowest set of data, i.e., top x or top x percent
of best or worst selling items with the ASC or DESC parameter. Here, `(number|percent)` specifies the exact number of records or the percentage of records you wish to pull from the database.
TOP syntax
It’s imperative to note that using the TOP clause without the ORDER BY statement might give unpredictable results as databases don’t guarantee the order of rows by default. The SQL SELECT TOP statement is used to retrieve records from one or more tables in a database and limit the number of records returned based on a fixed value or percentage. Mastering the SQL TOP clause has the power to significantly boost your database querying skills. By efficiently retrieving only the data you need, you’ll save time and resources, making your applications run smoother.
- This can lead to unexpected order of the results, which I’ve mentioned earlier.
- For instance, when we want to return
the first 10 rows of the table we can set this parameter as 10. - Remember, the key to leveraging the TOP clause effectively lies in combining it with the ORDER BY statement to ensure you’re getting the most relevant data.
- In this tutorial you will learn how to retrieve fixed number of records from the table.
There are two ways to determine the number of rows returned by the TOP clause. We can specify either the number of rows or the percentage of the result set to
return. ROW_NUMBER function helps to give temporary numbers to the result set of the query and it can be also used instead
of the TOP clauses.
SQL TOP WITH TIES
This SQL SELECT TOP example would select the first 10% of the records from the full result set. So in this example, the SELECT statement would return the top 10% of records from the contacts table where the last_name is ‘Anderson’. The other 90% of the result set would not be returned by the SELECT statement.
These practical examples highlight the versatility and potential pitfalls of the SQL TOP clause. By keeping these tips in mind and practicing with real queries, I’ve found that navigating the complexities of SQL data retrieval becomes far more manageable. In MySQL or PostgreSQL, this is how we’d achieve the same result as our first example.
SQL TOP PERCENT
In this tutorial, we will learn how to use SQL SELECT TOP queries and strengthen our understanding with examples. MySQL provides an equivalent LIMIT clause, whereas Oracle provides ROWNUM clause for the SELECT statement to restrict the number of rows returned by a query. In this article, we have talked about the SQL SELECT TOP statements, this query structure helps to limit the result
set of the queries. At the same time, we have learned some alternatives to the TOP clauses.
In the event of a tie, additional records beyond the last record of that tie,
as specified in the ORDER BY clause, will be included in the result set. In the event of a tie, the result set will include additional records beyond
the last record of that tie, as specified in the ORDER BY clause. We’ve seen how the ORDER BY clause is used to sort records before limiting
what’s returned with the TOP clause. Now, we’ll look at using the GROUP
BY and HAVING clauses to group and filter the records returned. In SQL Server, this is the standard syntax, but it’s essential to be aware of variations across different database systems. For instance, in MySQL and PostgreSQL, the LIMIT clause and the LIMIT and FETCH clauses are used respectively, instead of TOP.
Using SQL UPDATE TOP statement
In this article, I’ll share insights and tips on how to wield SQL TOP like a pro. Add the ORDER BY keyword when you want to sort the result, and return the first 3 records of the sorted result. The TOP clause can be used with the DELETE statement to delete a specific number of rows that meet the given criteria. Where, value is the number/ percentage of number of rows to return from the top. The following statement returns top 30 percent of the highest-paid employees. The following statement returns top three highest-paid employees from the employees table.
As we can see, the query has returned more than one product whose costs are the same as the first one. To return only the highest 50 percent of pretax amounts is achieved by adding
a TOP 50 PERCENT to the SELECT statement. The following examples were run in SQL Server Management Studio (SSMS) 19.2 against
a copy of the
Wide World Importers sample database on a Microsoft SQL Server 2022 server. Understanding the nuances and applying these practices in real-world scenarios elevates the precision and performance of data retrieval in SQL. Practicing with these variations and avoiding common pitfalls is essential in mastering the SQL TOP clause. Again, note how the ORDER BY clause ensures that we’re getting the latest products, not just any random selection.
Practical Examples of SQL TOP
This can lead to unexpected order of the results, which I’ve mentioned earlier. Another is attempting to use TOP in a subquery without an alias, which can result in errors or misunderstandings about which part of the query the TOP is meant to apply to. Incorporating SQL TOP into your queries, when done correctly, can significantly enhance both the performance and accuracy of your data retrieval efforts.
As a result, it is best practice to utilize the TOP clause in conjunction with an ORDER BY to produce a specific sorted result. The WITH TIES keyword enables to include the rows into the result set that matches with the last
row. We need to take into account one point about the WITH TIES, usage of this expression in the queries may cause
more rows to be returned than we specify in the TOP expression.
SQL TOP
For example, the following query will return the first 4 rows of the Product table. The PERCENT keyword specifies that the query will return rows by %n proportion of the result set. Such as, if we want to retrieve half of the rows in a table, it would be sufficient to set this
value to 50.
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