Java如何在可滚动结果集中移动光标?
package org.nhooo.example.jdbc;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class ScrollableMoveExample {
private static final String URL = "jdbc:mysql://localhost/nhooo";
private static final String USERNAME = "root";
private static final String PASSWORD = "";
public static void main(String[] args) {
try (Connection connection =
DriverManager.getConnection(URL, USERNAME, PASSWORD)) {
//在此示例中,我们首先创建一个语句,该语句允许我们
//在结果集对象中来回移动。首先,我们将
//从头到尾迭代结果。
Statement statement = connection.createStatement(
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY);
String sql = "SELECT id, code, name, price FROM products";
ResultSet resultSet = statement.executeQuery(sql);
while (resultSet.next()) {
print(resultSet);
}
System.out.println();
//现在,结果集指针放置在最后一条记录之后。
//使用结果集的先前方法,我们现在可以移动
//向后指向结果集开头的指针。
while (resultSet.previous()) {
print(resultSet);
}
} catch (SQLException e) {
e.printStackTrace();
}
}
private static void print(ResultSet resultSet) throws SQLException {
long id = resultSet.getLong("id");
String code = resultSet.getString("code");
String name = resultSet.getString("name");
double price = resultSet.getDouble("price");
System.out.println(id + "\t" + code + "\t" + name + "\t" + price);
}
}这是我们程序的一些结果。
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Maven依赖
<!-- https://search.maven.org/remotecontent?filepath=mysql/mysql-connector-java/8.0.17/mysql-connector-java-8.0.17.jar -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.17</version>
</dependency>