Mysql updating records

09 Oct

For multiple-table updates, there is no guarantee that assignments are carried out in any particular order.If you set a column to the value it currently has, My SQL notices this and does not update it.class, and a sample My SQL database table we can work with.The first thing we need for our Java UPDATE example is a sample My SQL database table.This will use the SQL UPDATE command with the WHERE clause to update the selected data in the My SQL table tutorials_tbl.The following example will update the tutorial_title field for a record having the tutorial_id as 3.

Other than that, this My SQL database table is relatively normal, though it is greatly simplified.

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.

In particular, the field "num_points" is a little unusual.

(Bug #11758262, Bug #50439) See Section 16.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”, for more information.

If you access a column from the table to be updated in an expression, assignments are generally evaluated from left to right.