十行Top 10 Rows from Oracle Database（oracle获取前）

With the advancement of technology and the world’s increasing reliance on data, having an Oracle Database is now essential to provide companies with the right data to make informed decisions. Oracle Database is responsible for store, manage and retrieve data. One of the first tasks for users of Oracle Database is to pull top 10 rows from a table. Here is a quick guide on how to achieve it.

First, define the criteria for the desired records. This can be done through a WHERE clause, which means selecting only rows from the table that meet certain criteria. For example, if you would like to retrieve the top 10 orders of 2018 based on a sales amount, the WHERE clause will be ‘WHERE OrderDate = ‘2018’.

Second, define the sort order of the rows. This can be done by using the ORDER BY clause which can order the result set by an ascending numerical order, or by a descending order of the column being selected. For example, if you would like to retrieve the top 10 orders of 2018 based on a sales amount, the ORDER BY clause will be ‘ORDER BY SalesAmount DESC’.

Third, select only the desired column from the table. This can be done by using the SELECT clause which allows us to retrieve only the desired columns from the table. For example, if you would like to retrieve the top 10 orders of 2018 based on a sales amount, the SELECT clause will be ‘SELECT id, OrderDate, SalesAmount’.

Fourth, limit the number of rows. This can be done by using the LIMIT clause. This will limit the number of results returned from the query. For example, if you would like to retrieve the top 10 orders of 2018 based on a sales amount, the LIMIT clause will be ‘LIMIT 10’.

Lastly, combine the above clauses into a single query. To do this, we need the FROM clause, which defines which table in the database to select from. For example, if you would like to retrieve the top 10 orders of 2018 based on a sales amount, the FROM clause will be ‘FROM orders’.

Now, to retrieve the top 10 rows from the Oracle Database table, enter the following query into the SQL language processing tool:

SELECT id, OrderDate, SalesAmount

FROM orders

WHERE OrderDate = ‘2018’

ORDER BY SalesAmount DESC

LIMIT 10

If the query is successfully executed, then Oracle Database will return the result set containing the top 10 rows of the table. By following these steps, it is quite simple to pull the top 10 rows from Oracle Database.