java how retrieve data from database

Question

I have code

public static String getData(String query) {
        String output = "";
        try {
            String connectionUrl = "jdbc:sqlserver://localhost:1234;databaseName=123;user=123;password=123";
            Connection con = null;
            Statement stmt = null;
            ResultSet rs = null;
                Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
                con = DriverManager.getConnection(connectionUrl);
                String SQL = "select smth from tableName where smth";
                stmt = con.createStatement();
                rs = stmt.executeQuery(query);
                while (rs.next()) {
                    output =  (String) rs.getObject(1);
                }
                rs.close();
        }
        catch (Exception e) {

            return "ERROR while retrieving data: " + e.getMessage();
        }
        return output;
    }

It works if value is string. But if it integer? Or boolean? How to modify this method so it would be universal, no matter what type data I get I still return it as string?

Answer 1

First retreive the result in ResultSet rs, then you can write the code like below.

You can check the instance of the object and than assign the value.

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String str;

Object obj = (Object)rs.getObject(1);

if(obj instanceof String){
   //do you work here for string like below
     str=(String)obj;
}
else if (obj instanceof Integer){
   //do your work for Integer
}

// same you can do for other types

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