Java如何在CallableStatement中注册参数？
本示例说明如何使用CallableStatement.registerOutParameter()方法调用注销用于执行存储过程的参数。 我们必须在执行查询之前注册out参数。 registerOutParameter()方法采用两个参数，参数的索引和out参数的sql数据类型。
package org.nhooo.example.jdbc;
import java.sql.*;
public class RegisterOutParameter {
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)) {
// 创建一个CallableStatement来执行存储的
// 程序
String query = "call GetDetailByName(?, ?, ?)";
CallableStatement cb = connection.prepareCall(query);
// 设置输入参数
cb.setString(1, "Ruby on Rails");
// 注册输出参数
cb.registerOutParameter(2, Types.VARCHAR);
cb.registerOutParameter(3, Types.DECIMAL);
// 执行查询
cb.executeQuery();
// 获取查询结果输出
System.out.println("Name : " + cb.getString(1));
System.out.println("Code : " + cb.getString(2));
System.out.println("Price : " + cb.getBigDecimal(3));
} catch (SQLException e) {
e.printStackTrace();
}
}
}这是我们在上面的代码中调用的MySQL存储过程。
DELIMITER ;;
DROP PROCEDURE IF EXISTS `GetDetailByName`;;
CREATE PROCEDURE `GetDetailByName`(INOUT product_name VARCHAR(50),
OUT product_code VARCHAR(10),
OUT product_price DECIMAL(10, 2))
BEGIN
SELECT code INTO product_code FROM products WHERE name = product_name;
SELECT price INTO product_price FROM products WHERE name = product_name;
END;;
DELIMITER ;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>