无法检索我想要使用存储过程选择的值

Question

I'm trying to find a record. Which let me choose to find a existing record in my database using Stored Procedure. When I tried to search a existing data it doesn't give me the value that I want. When I hit the search button it's not printing the value to the textfield.

CODE

private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {

  String searchSection = Section_SearchSection_Textfield.getText();
  String searchSection_Name = Section_SectionName_TextField.getText();
  int sectionID = 0;

  if (searchSection.isEmpty())
    {
        JOptionPane.showMessageDialog(null, "Please fill up this fields");
    }
  else 
        try (Connection myConn = DBUtil.connect())
        {   
            try (CallableStatement myFirstCs = myConn.prepareCall("{call getSECTION_NAME(?,?)}"))
            {
                myFirstCs.setInt(1, sectionID);// I set the ID for Primary Key
                myFirstCs.registerOutParameter(2, Types.VARCHAR);
                myFirstCs.setString(2, searchSection_Name);


                boolean hasresults = myFirstCs.execute();

            if (hasresults)
            {
            try (ResultSet myRs = myFirstCs.getResultSet())
            {
                int resultsCounter = 0;
                while (myRs.next())
                {
                    sectionID = myRs.getInt("SECTION_ID");
                    String sectionName = myRs.getString(2);
                    Section_SectionName_TextField.setText(sectionName);//Set the value of text
                    Section_SectionName_TextField.setEnabled(true);//Set to enable

                    resultsCounter++;

                }//end of while
               }//end of if
               }//end of resultset
            }//end of callablestatement
        }//end of connection
        catch (SQLException e) 
        {
            DBUtil.processException(e);
        }
}

Stored Procedure

CREATE PROCEDURE getSECTION_NAME(IN ID INT, OUT NAME VARCHAR(50))
SELECT * FROM allsections_list WHERE SECTION_ID = ID AND SECTION_NAME = NAME

Table

CREATE TABLE
(
SECTION_ID INT PRIMARY KEY AUTO_INCREMENT,
SECTION_NAME VARCHAR(50) NOT NULL
)

Any help would be appreciated! Thanks!

Update! According to what I read Stored Procedure can return a result set. I want to retrieve the values of the OUT parameter.

private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    String searchSection = Section_SearchSection_Textfield.getText();
    String searchSection_Name = Section_SectionName_TextField.getText();

    if (searchSection.isEmpty())
    {
        JOptionPane.showMessageDialog(null, "Please fill up this fields");
    }
    else 
        try (Connection myConn = DBUtil.connect();
             CallableStatement myFirstCs = myConn.prepareCall("{call getSECTION_NAME(?,?)}"))
        {

             myFirstCs.setInt(1, sectionID);// I set the ID for Primary Key
             myFirstCs.registerOutParameter(2, Types.VARCHAR);

            boolean hasresults = myFirstCs.execute();

        if (hasresults)
        {
        try (ResultSet myRs = myFirstCs.getResultSet())
        {
            while (myRs.next())
            {
                sectionID = myRs.getInt("SECTION_ID");

                System.out.print(sectionID);
            }//end of while

        }//end of resultset
        }//end of if
                String sectionName = myFirstCs.getString(2);
                Section_SectionName_TextField.setText(sectionName);//Set the value of text
                Section_SectionName_TextField.setEnabled(true);//Set to enable
                System.out.print(sectionName);
        }//end of connection
        catch (SQLException e) 
        {
            DBUtil.processException(e);
        }

}

I removed the String sectionName = myRs.getString(2); Section_SectionName_TextField.setText(sectionName); Section_SectionName_TextField.setEnabled(true); String sectionName = myRs.getString(2); Section_SectionName_TextField.setText(sectionName); Section_SectionName_TextField.setEnabled(true); out of the Result Set block and put it in the Callable Statement block. When I run the program. The only changes is the textfield become enabled and prints me a "null" value.

2nd Update! I want to returned the values of OUT parameter I should not use Result Set to retrieve it. So I used Callable Statement parameter with OUT parameter of stored procedure according to @Gord Thompson.

private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    String searchSection = Section_SearchSection_Textfield.getText();
    String searchSection_Name = Section_SectionName_TextField.getText();
    if (searchSection.isEmpty())
    {
        JOptionPane.showMessageDialog(null, "Please fill up this fields");
    }
    else 
        try (Connection myConn = DBUtil.connect();
             CallableStatement myFirstCs = myConn.prepareCall("{call getSECTION_NAME(?,?)}"))
        {

             myFirstCs.setInt(1, 2);// I set the ID for Primary Key
             myFirstCs.registerOutParameter(2, Types.VARCHAR);
             myFirstCs.execute();

             String sectionName = myFirstCs.getString(2);  // retrieve value from OUT parameter
             Section_SectionName_TextField.setText(sectionName);//Set the value of text
             Section_SectionName_TextField.setEnabled(true);//Set to enable
             System.out.println(sectionName);

        }//end of connection
        catch (SQLException e) 
        { 
            DBUtil.processException(e);
        }
}

Its still giving me a null values where I don't why I getting this value.

The only changes to my GUI is the textfield become enabled and it's not printing the value I want in the following textfield. :(

Thanks for responding. Feel free to comment.

Answer 1

If you want the value that is returned via an OUT parameter of a stored procedure then you don't use a ResultSet, you use the CallableStatement parameter associated with the OUT parameter of the stored procedure. For example, for the test table

CREATE TABLE `allsections_list` (
 `SECTION_ID` int(11) NOT NULL,
 `SECTION_NAME` varchar(50) DEFAULT NULL,
 PRIMARY KEY (`SECTION_ID`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

containing the sample data

SECTION_ID  SECTION_NAME
----------  ---------------
         1  one_section
         2  another_section

and the stored procedure

CREATE PROCEDURE `getSECTION_NAME`(IN myID INT, OUT myName VARCHAR(50))
BEGIN
   SELECT SECTION_NAME INTO myName FROM allsections_list WHERE SECTION_ID = myID;
END

then the following Java code

try (CallableStatement myFirstCs = conn.prepareCall("{call getSECTION_NAME(?,?)}")) {
    myFirstCs.setInt(1, 2);  // set IN parameter "myID" to value 2
    myFirstCs.registerOutParameter(2, Types.VARCHAR);
    myFirstCs.execute();
    String sectionName = myFirstCs.getString(2);  // get value from OUT parameter "myName"
    System.out.println(sectionName);
}

prints

another_section

Answer 2

you should use delimiter to change the delimiter to something different than ";" when you create the procedure:

delimiter //
CREATE PROCEDURE getSECTION_NAME(IN ID INT, OUT NAME VARCHAR(50)) 
BEGIN 
  SELECT SECTION_NAME INTO NAME FROM allsections_list WHERE SECTION_ID = ID; 
END    
//
delimiter ;

The first delimiter statement sets the delimiter to "//". This way, the ";" in your stored procedure code is not interpreted as a delimiter anymore. Your CREATE PROCEDURE statement then correctly ends at the "//". Aftwerwards, the second delimiter statement changes the delimiter back to ";".