{"id":94314,"date":"2019-10-14T12:22:45","date_gmt":"2019-10-14T17:22:45","guid":{"rendered":"https:\/\/wpengine.com\/?post_type=resource&p=94314"},"modified":"2024-09-28T13:49:13","modified_gmt":"2024-09-28T18:49:13","slug":"mysql-wordpress","status":"publish","type":"resource","link":"https:\/\/wpengine.com\/case-studies\/resources\/mysql-wordpress\/","title":{"rendered":"Using MySQL With WordPress"},"content":{"rendered":"\n

If you manage a WordPress website, you may have found yourself wanting to know more about how its database<\/a> functions. It\u2019s useful to understand how your site works behind the scenes, and there may even be times when you need to access your site\u2019s database directly. <\/p>\n\n\n\n

That\u2019s where MySQL<\/a> comes in. Structured Query Language (SQL) is the management system for WordPress\u2019 databases. We\u2019ll go into greater detail later, but suffice it to say that the database is the brains of your website and MySQL is the nervous system, sending commands back and forth to retrieve information and execute operations. <\/p>\n\n\n\n

In this article, we\u2019ll provide a detailed explanation of how MySQL works in regards to WordPress. Additionally, we\u2019ll review several database errors you might encounter and explain how to remedy them. <\/p>\n\n\n\n

Let\u2019s dive right in!<\/p>\n\n\n\n

MySQL Explained<\/h2>\n\n\n\n

You may have heard a database described before as a filing cabinet, a place to hold all of your site\u2019s important information in categorized slots. In this analogy, the individual folders within the cabinet are the database tables that hold information.<\/p>\n\n\n\n

As for MySQL, it\u2019s how requests are made to place or remove data within these folders. You can also use MySQL to set rules for what is allowed to be placed in each part of the filing cabinet.  <\/p>\n\n\n\n

MySQL can\u2019t operate alone, however. It is part of a stack of software applications used to create websites. The other components include Linux, Apache, MySQL, and PHP (LAMP<\/a>). Together, they form the “dream team” of the open-source programming world. <\/p>\n\n\n\n

Using MySQL for WordPress<\/h2>\n\n\n\n

When it comes to WordPress, the PHP scripting language is used to send and retrieve information from your MySQL database. These two elements handle everything from logging in site users, to storing theme and plugin information for dynamic content display. <\/p>\n\n\n\n

MySQL uses table structures to store data. Most web hosts come with a MySQL user interface software called phpMyAdmin<\/a>. This free and open-source piece of software makes it easy to run database commands. It enables you to edit, delete, or create tables, rows, and fields:<\/p>\n\n\n\n

During a standard WordPress installation, 12 tables are created in your database. You can see them listed on the left in the above image. These tables include key information required for your site to function.<\/p>\n\n\n\n

For example, the wp_options <\/em>table stores the options you can access and control from the Settings<\/em> menu in your WordPress dashboard. It\u2019s also the home to your various widget-related settings.<\/p>\n\n\n\n

As you can see in the phpMyAdmin panel, information about all the data contained in any table will be visible when you click on its name. This includes any values or parameters associated with specific fields.<\/p>\n\n\n\n

MySQL Plugins\/Extensions<\/h2>\n\n\n\n

While there aren’t many plugins that directly enhance MySQL functionality within WordPress, there are a few tools worth checking out if you plan on manually changing or altering your database often.<\/p>\n\n\n\n

For example, WP phpMyAdmin<\/a> is a useful plugin if you want to be able to access your site\u2019s phpMyAdmin panel from within your WordPress dashboard, rather than through your web host\u2019s control panel:<\/p>\n\n\n\n

This is a simple but popular solution that offers convenient access to your database. That can also make it a bit easier to resolve MySQL-related errors, as we\u2019ll see below.<\/p>\n\n\n\n

Common MySQL Errors in WordPress (And How to Solve Them)<\/h2>\n\n\n\n

Database errors can happen to anyone, but can be frustrating to deal with. To make your life simpler, it helps to understand the most common problems that can arise, as well as each one\u2019s likely solutions. <\/p>\n\n\n\n

Let\u2019s look at five examples of typical MySQL issues.<\/p>\n\n\n\n

1. Error Establishing a Database Connection<\/h3>\n\n\n\n

If you encounter a message like \u201cError establishing a database connection\u201d when trying to access your site, it likely means that your URL is pointing to the wrong database or your site is encountering a connection error.<\/p>\n\n\n\n

A database connection error means that you won\u2019t be able to access your website. You\u2019ll likely also be blocked from logging in to your administration panel. In this scenario, your wp-config.php<\/em> file is most likely the culprit.<\/p>\n\n\n\n

The first way you can resolve this issue is by accessing your site\u2019s hosting account<\/a> and restoring a recent backup. This will reset your wp-config.php<\/em> file, giving you access to your administration panel. If it\u2019s not possible to access a backup of your site, however, there is another solution.<\/p>\n\n\n\n

You can also edit your wp-config.php<\/em> file using a Secure File Transfer Protocol (SFTP)<\/a> application like FileZilla<\/a>. Once you connect to your website, your wp-config.php<\/em> file can be found in the root directory of your site\u2019s files.<\/p>\n\n\n\n

If you open the file, you\u2019ll see all your database information near the top. You can then check to see if there is a mistake in your database name, user name, or any other information regarding your site.<\/p>\n\n\n\n

You may need to contact your host if you are unsure of what this information should include. You\u2019ll be mostly concerned with verifying the correct \u201cDB_USER\u201d, \u201cDB_PASSWORD\u201d, and \u201cDB_HOST.\u201d <\/p>\n\n\n\n

Once you complete the necessary corrections, be sure to save your changes and upload the file back to your site\u2019s server. <\/p>\n\n\n\n

2. Error #1005<\/h3>\n\n\n\n

The #1005 error is a server-side issue, rather than a problem with your site. It occurs when a necessary table could not be created. Depending on the details of the message string, you may get more information about the cause of the error.<\/p>\n\n\n\n

For instance, your error message might look like this: <\/p>\n\n\n\n

Can't create table '%s' (errno: %d)<\/pre>\n\n\n\n
The most common \u201cerrno\u201d with this particular issue is \u201c(errno: 150).\u201d This means there is a foreign key constraint<\/a> issue. In other words, it\u2019s likely that the table you are trying to create conflicts with a set constraint. The error is preventing inconsistencies from occurring in data between multiple tables. <\/p>\n\n\n\n
In order to solve a foreign key constraint error, you\u2019ll need to do a little investigating and check your database tables for inconsistencies. This means you\u2019ll want to: <\/p>\n\n\n\n