Common Errors with CallableStatement Parameters

This section provides some error conditions on CallableStatement place holder parameters.

While testing CallableStatement objects with place holder parameters, I noticed two common errors as shown in this program:

/* MySqlCallParameterError.java
 * Copyright (c) HerongYang.com. All Rights Reserved.
 */
import java.sql.*;
public class MySqlCallParameterError {
  public static void main(String [] args) {
    Connection con = null;
    try {
      com.mysql.cj.jdbc.MysqlDataSource ds
        = new com.mysql.cj.jdbc.MysqlDataSource();
      ds.setServerName("localhost");
      ds.setPortNumber(3306);
      ds.setDatabaseName("HerongDB");
      ds.setUser("Herong");
      ds.setPassword("TopSecret");
      con = ds.getConnection();

// Create CallableStatement
      CallableStatement cs = con.prepareCall(
        "CALL ReverseProcedure(?,?,?)");

// Provide values for IN parameters
// Error 2 - Forget to provide values for IN parameters
      String word = "Herong";
      cs.setString(1,word);

// Register OUT parameters
// Error 1 - Can not register OUT parameters
      cs.registerOutParameter(1, java.sql.Types.VARCHAR);
      cs.registerOutParameter(2, java.sql.Types.VARCHAR);
      cs.registerOutParameter(3, java.sql.Types.INTEGER);

// Execute the CALL statement and ignore result sets
      cs.executeUpdate();

// Retrieve values from OUT parameters
      String reversed = cs.getString(2);
      int length = cs.getInt(3);
      System.out.println("Input word: "+word);
      System.out.println("Output word: "+reversed);
      System.out.println("Word length: "+length);

// Close resource
      cs.close();

      con.close();
    } catch (Exception e) {
      System.err.println("Exception: "+e.getMessage());
      e.printStackTrace();
    }
  }
}

Compile and run this program as is, you will get this error message at line 28, because registering an IN parameter as statement output parameter is not allowed:

herong> java -cp .:mysql-connector-java.jar \
   MySqlCallParameterError.java

java.sql.SQLException: Parameter number 1 is not an OUT parameter
  at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(...)
  at com.mysql.cj.jdbc.CallableStatement.checkIsOutputParam(...)
  at com.mysql.cj.jdbc.CallableStatement.registerOutParameter(...)
  at MySqlCallParameterError.main(MySqlCallParameterError.java:29)

Table of Contents

 About This Book

 JDBC (Java Database Connectivity) Introduction

 JDK (Java SE) Installation

 MySQL Installation on Windows

 MySQL JDBC Driver (MySQL Connector/J)

 MySQL - PreparedStatement

 MySQL - Reference Implementation of JdbcRowSet

MySQL - JBDC CallableStatement

 Overview of CallableStatement Objects

 "CREATE PROCEDURE" - Creating a Simple Procedure

 Creating Procedures with IN and OUT Parameters

 Creating Procedures with INOUT Parameters

 Creating Procedures with Multiple Queries

 Creating CallableStatement Objects with prepareCall()

 Capturing ResultSet with executeQuery()

 Creating CallableStatement Objects with Parameters

Common Errors with CallableStatement Parameters

 Creating CallableStatement Objects with INOUT Parameters

 Retrieving Multiple ResultSet Objects

 Executing Stored Procedures without Permission

 getProcedures() - Listing Stored Procedures

 MySQL CLOB (Character Large Object) - TEXT

 MySQL BLOB (Binary Large Object) - BLOB

 Using Connection Pool with JDBC

 Archived Tutorials

 References

 Full Version in PDF/EPUB