screenupdating excel false - Mysql updating multiple rows

by  |  23-Feb-2018 03:16

It will be as simple as possible, I just want to show You how to use ON DUPLICATE KEY UPDATE:) CREATE TABLE `stats` ( `id` int(11) NOT NULL AUTO_INCREMENT, `article_id` int(11) NOT NULL, `views_count` int(11) NOT NULL DEFAULT '1', `created` date NOT NULL, PRIMARY KEY (`id`) ) ENGINE=Inno DB DEFAULT CHARSET=utf8 field by 1. Let's take a look at this example: INSERT INTO stats (article_id, created) VALUES (12, CURRENT_DATE()) ON DUPLICATE KEY UPDATE views_count = IF(VALUES(article_id) = 12, views_count 2, views_count 1) /*, additional_field = additional_field 1, next_field = IF(article_id = 1, 1, 0). It has three parts, condition, value if true, value if false.

So let's create really simple query that will insert the data to database or update the existing one. For testing purposes You can change CURRENT_DATE() function to the particular date, for instance "2012-12-12" to see how it really works.

Mysql updating multiple rows

In this article I’ll give an overview of each feature, help you understand how to choose among them, and point out some things to watch out for. I assume My ISAM tables without support for transactions, with the following sample data: create table t1 ( a int not null primary key, b int not null, c int not null ) type=My ISAM; create table t2 ( d int not null primary key, e int not null, f int not null ) type=My ISAM; insert into t1 (a, b, c) values (1, 2, 3), (2, 4, 6), (3, 6, 9); insert into t2 (d, e, f) values (1, 1, 1), (4, 4, 4), (5, 5, 5);.

Recall that in My SQL, a primary key is simply a unique index named PRIMARY.

So this condition will be true and Keep in mind, that on first insert, when there's no record in the table, insert will be performed.

It means that all code after ON DUPLICATE KEY UPDATE won't be executed.

We can't use our example as there is only creation date of the first insert. If we named our index we can simply execute this query to remove the unique key: date.

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