从Java（Eclipse）调用MySQL存储过程中的OUT参数错误

Question

I am trying to call a MySql stored procedure from the Java code in Eclipse but I get the following error. The stored procedure compiled without any error.

Import statements:

import java.sql.CallableStatement;    
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;

Here's the java code snippet:

>cStmt = (CallableStatement) conn.prepareCall("{ call getEmpName(?,?)}");

>cStmt.setString(1, "xxxyyyzzz");

>cStmt.registerOutParameter(2, Types.INTEGER);

>cStmt.execute();

Given below is the Stored procedure

>USE `mcaSchema`;
>DROP procedure IF EXISTS `getEmpName`;
>DELIMITER $$
>USE `mcaSchema`$$
>CREATE DEFINER=`root`@`localhost` PROCEDURE `getEmpName`(IN empID int,OUT eName varchar(30)) 
>BEGIN
>>  select ename from mcaSchema.emp where empno = empID; 
>END$$
>DELIMITER ;

Please help me figure out what wrong I am doing. Pardon me if it seems a lil' naive. I've looked around for solution, but haven't been able to resolve it . ...

Answer 1

Try:

/* CODE FOR DEMONSTRATION PURPOSES */
DROP PROCEDURE IF EXISTS `getEmpName`;

DELIMITER $$

CREATE PROCEDURE `getEmpName`(IN `empID` VARCHAR(30), OUT `eName` VARCHAR(30)) 
BEGIN
    SELECT CONCAT('NAME: ' , `empID`) INTO `eName`;
END$$

DELIMITER ;
/* CODE FOR DEMONSTRATION PURPOSES */

/* CODE FOR DEMONSTRATION PURPOSES */
...
cStmt = con.prepareCall("{ call `getEmpName`(?, ?) }");
cStmt.setString(1, "MYNAME");
cStmt.registerOutParameter(2, Types.VARCHAR);
boolean hadResults = cStmt.execute();
while (hadResults) {
   rs = cStmt.getResultSet();
   hadResults = cStmt.getMoreResults();
}
String outputValue = cStmt.getString(2);
...
/* CODE FOR DEMONSTRATION PURPOSES */

UPDATE

DROP PROCEDURE IF EXISTS `getEmpName`;

DELIMITER $$

CREATE PROCEDURE `getEmpName`(IN `p_empID` INT, OUT `p_eName` VARCHAR(30)) 
BEGIN
    SELECT `ename` INTO `p_eName`
    FROM `mcaSchema`.`emp`
    WHERE `empno` = `p_empID`; 
END$$

DELIMITER ;