How to create MySQL Procedures from java code when software runs for first time (Setting up database procedures))

Question

I want to setup my database when my application runs on a new device for the first time. For this, I have to create necessary tables, stored procedures, etc. I successfully created tables on the initial start of the application. But I'm not able to implement the same for procedures.

I tried executing the stored procedure query when the application is started the first time. Although the MySQL code to create procedure is correct, Java gives an error saying
java.sql.BatchUpdateException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DELIMITER // CREATE PROCEDURE update_registered_fields (IN _field VARCHAR(200))' at line 1 If I run the same query in MySQL webview it runs perfectly.

I have not shown the connection to the database here as it is working fine. And I have used procedures.xml file to get a query for the code.

DatabaseHandler.java

private static void inflateProcedure() throws SQLException, FileNotFoundException, ParserConfigurationException, SAXException, IOException{
    Set<String> set = new HashSet<>();
    List<String> procedureData = new ArrayList<>();
    String query = "SHOW PROCEDURE STATUS WHERE Db = '"+Preferences.getPreferences().getDatabaseName()+"';";
    System.out.println(query);
    stmnt = con.createStatement();
    ResultSet rs = stmnt.executeQuery(query);
    while(rs.next()){
        set.add(rs.getString("NAME").toLowerCase());
    }
    System.out.println("Already Loaded Procedures "+set);
    DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
    DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
    Document doc = dBuilder.parse(new FileInputStream(Preferences.getPreferences().getLocation()+"procedures.xml"));
    NodeList nList = doc.getElementsByTagName("table-entry");
    for (int i = 0; i < nList.getLength(); i++) {
        Node nNode = nList.item(i);
        Element entry = (Element) nNode;
        String procedureName = entry.getAttribute("name");
        String params = entry.getAttribute("params");
        String procedureQuery = entry.getAttribute("data");
        if (!set.contains(procedureName.toLowerCase())) {
            procedureData.add(String.format("DELIMITER // CREATE PROCEDURE %s %s \n"
                    + "BEGIN;\n"
                    + " %s \n"
                    + "END //\n DELIMITER ", procedureName, params, procedureQuery));
        }
    }
    if (procedureData.isEmpty()) {
        System.out.println("Procedures are already loaded");
    }
    else {
        System.out.println("Inflating new Procedures.");
        createProcedures(procedureData);
    }
}

private static void createProcedures(List<String> procedureData) throws SQLException{
    Statement statement = con.createStatement();
    for (String command : procedureData) {
        System.out.println(command);
        statement.addBatch(command);
    }
    statement.executeBatch();
    statement.close();
}

procedures.xml

<procedures>
<table-entry name="update_registered_fields" params="(IN _field VARCHAR(200))" data="DECLARE _value INT DEFAULT 0;

    SET _value := (SELECT `user_register_feilds`.`last_used` FROM `user_register_feilds` WHERE `user_register_feilds`.`name` = _field);
    UPDATE `user_register_feilds` SET `user_register_feilds`.`last_used` = _value+1 WHERE `user_register_feilds`.`name` = _field;"/>

<table-entry name="sort_fields" params="(IN _value INT(50))" data="SELECT * FROM user_enquiry ORDER BY last_used DESC, id ASC LIMIT _value;"/>

I want to execute this query. I have even tried allowMultiQueries . I also want to know is this the correct way to fill the database when we start the application for the first time.

Answer 1

You seem to have used delimiters in your sql query, that you're trying to run in JDBC, which is apparent from your error message: java.sql.BatchUpdateException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DELIMITER // CREATE PROCEDURE update_registered_fields (IN _field VARCHAR(200))' at line 1 java.sql.BatchUpdateException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DELIMITER // CREATE PROCEDURE update_registered_fields (IN _field VARCHAR(200))' at line 1 .

Try removing the delimiters. Delimiters are used in raw sql. JDBC doesn't need delimiters.