如何在JDBC中使用可调用语句调用存储过程说明？
您可以使用CallableStatement接口调用SQL存储过程。Callable语句可以具有输入参数和/或输出参数。
您可以使用Connection接口的prepareCall()方法创建CallableStatement（接口）的对象。此方法接受表示查询的字符串变量来调用存储过程，并返回CallableStatement对象。
假设您在数据库中有一个过程名称myProcedure，则可以将可调用语句准备为：
//Preparing a CallableStatement
CallableStatement cstmt = con.prepareCall("{call myProcedure(?, ?, ?)}");然后，您可以使用CallableStatement接口的setter方法为占位符设置值，并使用execute()如下所示的方法执行callable语句。
cstmt.setString(1, "Raghav"); cstmt.setInt(2, 3000); cstmt.setString(3, "Hyderabad"); cstmt.execute();
如果该过程没有输入值，则只需准备可调用语句并执行，如下所示：
CallableStatement cstmt = con.prepareCall("{call myProcedure()}");
cstmt.execute();示例
假设我们在MySQL数据库中有一个名为Dispatches的表，其中包含以下数据：
+--------------+------------------+------------------+----------------+ | Product_Name | Date_Of_Dispatch | Time_Of_Dispatch | Location | +--------------+------------------+------------------+----------------+ | KeyBoard | 1970-01-19 | 08:51:36 | Hyderabad | | Earphones | 1970-01-19 | 05:54:28 | Vishakhapatnam | | Mouse | 1970-01-19 | 04:26:38 | Vijayawada | +--------------+------------------+------------------+----------------+
并且如果我们创建了一个名为myProcedure的过程来从该表中检索值，如下所示：
Create procedure myProcedure () -> BEGIN -> SELECT * FROM Dispatches; -> END //
示例
以下是一个使用JDBC程序调用上述存储过程的JDBC示例。
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
public class CallingProcedure {
public static void main(String args[]) throws SQLException {
//注册驱动程序
DriverManager.registerDriver(new com.mysql.jdbc.Driver());
//获得连接
String mysqlUrl = "jdbc:mysql://localhost/sampleDB";
Connection con = DriverManager.getConnection(mysqlUrl, "root", "password");
System.out.println("Connection established......");
//准备一个CallableStatement-
CallableStatement cstmt = con.prepareCall("{call myProcedure()}");
//检索结果
ResultSet rs = cstmt.executeQuery();
while(rs.next()) {
System.out.println("Product Name: "+rs.getString("Product_Name"));
System.out.println("Date of Dispatch: "+rs.getDate("Date_Of_Dispatch"));
System.out.println("Time of Dispatch: "+rs.getTime("Time_Of_Dispatch"));
System.out.println("Location: "+rs.getString("Location"));
System.out.println();
}
}
}输出结果
Connection established...... Product Name: KeyBoard Date of Dispatch: 1970-01-19 Time of Dispatch: 08:51:36 Location: Hyderabad Product Name: Earphones Date of Dispatch: 1970-01-19 Time of Dispatch: 05:54:28 Location: Vishakhapatnam Product Name: Mouse Date of Dispatch: 1970-01-19 Time of Dispatch: 04:26:38 Location: Vijayawada