What is the usage of the SQL TOP statement?
The TOP statement is used to select a specified number of rows from query results. It is often used to sort query results and return the top few rows.
The basic syntax of using the TOP statement in SQL Server is as follows:
SELECT TOP(n) 列名
FROM 表名
WHERE 条件
ORDER BY 排序列
n specifies the number of rows to return. For example, if n=5, then the query will return the first 5 rows of the result.
Please note that there may be some syntax differences in TOP statements across different databases. For example, in MySQL, you can use the LIMIT keyword to achieve similar functionality.
SELECT 列名
FROM 表名
WHERE 条件
ORDER BY 排序列
LIMIT n
This will return the top n rows from the query results.
It is important to note that if you want to select the top N rows, you must use the ORDER BY clause to sort them to ensure the order of the results is clear. Otherwise, the order of the query results will not be guaranteed.