Updating database java
Although the target database system is My SQL, but the same technique can be applied for other database systems as well because the query syntax used is standard SQL which is supported by all relational database systems.We will learn how to do insert, query, update and delete database records by writing code to manage records of a table Users in a My SQL database called Sample DB. )"; Prepared Statement statement = conn.prepare Statement(sql); String(1, "bill"); String(2, "secretpass"); String(3, "Bill Gates"); String(4, "[email protected]"); int rows Inserted = statement.execute Update(); if (rows Inserted method to execute the INSERT statement.In the steps for creating a sample application in this chapter, a Java Bean is used to hold a single employee record.When a user wants to edit an existing record or add a new one, it is used as a container to hold the changed or new values for a single row of a table to prepare the row for using to update the database.create database Sample DB; use Sample DB; CREATE TABLE `users` ( `user_id` int(11) NOT NULL AUTO_INCREMENT, `username` varchar(45) NOT NULL, `password` varchar(45) NOT NULL, `fullname` varchar(45) NOT NULL, `email` varchar(45) NOT NULL, PRIMARY KEY (`user_id`) ); Practical Database Programming with Java - This book is for those who are beginner in Java database programming and want to catch up with the main database programming techniques with straightforward and easy to learn example code. This method returns an update count indicating how many rows in the table were affected by the query, so checking this return value is necessary to ensure the query was executed successfully.String sql = "INSERT INTO Users (username, password, fullname, email) VALUES (? In this case, method should return 1 to indicate one record was inserted.Given that My SQL database table design, let's assume that we just want to update one record in this table.
All the methods in the sample application include code for handling exceptions.The command line processor will validate whether the command line parameters are allowed for the current command.If the current command does not allow command line parameters or the parameter appears to be an incorrect format, then an error message of ‘unexpected command parmeter’ will be logged and the execution will terminate.To keep it simple — but also show several different data types — I've created the following My SQL database table: create table users ( id int unsigned auto_increment not null, first_name varchar(32) not null, last_name varchar(32) not null, date_created timestamp default now(), is_admin boolean, num_points int, primary key (id) ); -- insert some sample records insert into users (first_name, last_name) values ('Fred', 'Flinstone'); insert into users (first_name, last_name) values ('Barney', 'Rubble'); A few of these fields are a little contrived, but I wanted to show several different data types in one table, so this is what I came up with.