问题描述
当SQL查询的结果为零行时, executeQuery(String sql)
会返回什么?如果它返回 ResultSet
对象,我们将如何检测到SQL Query没有返回任何内容。
What will executeQuery(String sql)
return when the result of the SQL Query is zero rows>? If it returns a ResultSet
Object, how will we detect that the SQL Query has returned nothing.
假设SQL查询为 SELECT
语句。
Assume the SQL Query to be a SELECT
statement.
推荐答案
您检查了,因为Java中的Resultsets没有直接的size()或length()方法。
Did you check ResultSet's next method . Initially the ResultSet's cursor points to before the first row, the very first call to next() returns false implies there was no data in the ResultSet. See How do I get the size of a ResultSet? , since there is no direct size() or length() method for Resultsets in Java.
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