resultSet.last()什么意思 与rs.next()有什么区别 什么用 谢谢
------解决方案--------------------
last是讲cursor移到最后。
看API:
boolean last()
throws SQLException
Moves the cursor to the last row in this ResultSet object.
Returns:
true if the cursor is on a valid row; false if there are no rows in the result set
Throws:
SQLException - if a database access error occurs; this method is called on a closed result set or the result set type is TYPE_FORWARD_ONLY
SQLFeatureNotSupportedException - if the JDBC driver does not support this method
Since:
1.2
next是往下一行移到一个
看API：
boolean next()
throws SQLException
Moves the cursor froward one row from its current position. A ResultSet cursor is initially positioned before the first row; the first call to the method next makes the first row the current row; the second call makes the second row the current row, and so on.
When a call to the next method returns false, the cursor is positioned after the last row. Any invocation of a ResultSet method which requires a current row will result in a SQLException being thrown. If the result set type is TYPE_FORWARD_ONLY, it is vendor specified whether their JDBC driver implementation will return false or throw an SQLException on a subsequent call to next.
If an input stream is open for the current row, a call to the method next will implicitly close it. A ResultSet object's warning chain is cleared when a new row is read.
Returns:
true if the new current row is valid; false if there are no more rows
Throws:
SQLException - if a database access error occurs or this method is called on a closed result set
------解决方案--------------------
next是将游标移动到下一个位置。last当然是移到结果的最后一行咯。根据字面意思也可以理解。
------解决方案--------------------
last是讲cursor移到最后。
next是往下一行移到一个。