CODEWITHSUNDEEP
mysqljoin
user606263
user606263

Reputation:

MySQL statement to find data in two tables

I suck at doing joins in MySQL, and I'm pretty sure this is what I need to make this work (though correct me if I'm wrong).

So I have two tables. Here's the SQL to set-up a simple database:

CREATE TABLE IF NOT EXISTS `wp_usermeta` (
`umeta_id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`user_id` bigint(20) unsigned NOT NULL DEFAULT '0',
`meta_key` varchar(255) DEFAULT NULL,
`meta_value` longtext,
PRIMARY KEY (`umeta_id`),
KEY `user_id` (`user_id`),
KEY `meta_key` (`meta_key`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;


INSERT INTO `wp_usermeta` (`umeta_id`, `user_id`, `meta_key`, `meta_value`) VALUES
(1, 1, 'first_name', 'David'),
(2, 1, 'last_name', 'Jones'),
(3, 1, 'nickname', 'david'),
(4, 1, 'newsletter', '1'),
(5, 2, 'first_name', 'Greg'),
(6, 2, 'last_name', 'Smith'),
(7, 2, 'nickname', 'greg'),
(8, 2, 'newsletter', '0');

CREATE TABLE IF NOT EXISTS `wp_users` (
`ID` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`user_login` varchar(60) NOT NULL DEFAULT '',
`user_pass` varchar(64) NOT NULL DEFAULT '',
`user_nicename` varchar(50) NOT NULL DEFAULT '',
`user_email` varchar(100) NOT NULL DEFAULT '',
PRIMARY KEY (`ID`),
KEY `user_login_key` (`user_login`),
KEY `user_nicename` (`user_nicename`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;

INSERT INTO `wp_users` (`ID`, `user_login`, `user_pass`, `user_nicename`, `user_email`) VALUES
(1, 'david', '$^*#NNR&Y&)Mn9emfdfsdfsdfsd', 'david', '[email protected]'),
(2, 'greg', 'fdfsdfsdfsd$^*#NNR&Y&)Mn9em', 'greg', '[email protected]');

...and I need to write a statement for a basic page that simply finds the users who have subscribed to the newsletter (meta_key with a meta_value of 1) and displays their first_name and user_email.

Thanks in advance.

Upvotes: 0

Views: 124

Answers (1)

Joachim Isaksson
Joachim Isaksson

Reputation: 180917

It takes a fairly simple join;

SELECT user_login FROM wp_users
JOIN wp_usermeta
  ON wp_users.id=wp_usermeta.user_id
WHERE meta_key='newsletter'
  AND meta_value=1;

SQLfiddle to play with.

Upvotes: 1

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