One place for hosting & domains

      Tables

      How To Create and Customize Tables in HTML



      Part of the Series:
      How To Build a Website With HTML

      This tutorial series will guide you through creating and further customizing this website using HTML, the standard markup language used to display documents in a web browser. No prior coding experience is necessary but we recommend you start at the beginning of the series if you wish to recreate the demonstration website.

      At the end of this series, you should have a website ready to deploy to the cloud and a basic familiarity with HTML. Knowing how to write HTML will provide a strong foundation for learning additional front-end web development skills, such as CSS and JavaScript.

      HTML tables are useful for arranging content in rows and columns. This tutorial will teach you how to add a table to your webpage and how customize it by adding a desired amount of rows and columns.

      A <table> element requires the use of one or more table row <tr> elements, which create table rows, and one or more table data <td> elements, which insert content into table columns. Each of these elements require an opening and closing tag. The table data <td> elements go inside the table row <tr> elements, and the table row <tr> elements go inside the <table> elements. For example, here is a table that has two rows and three columns:

      <table>
      <tr> 
      <td> Column 1 </td>
      <td> Column 2 </td>
      <td> Column 3 </td>
      </tr>
      <tr> 
      <td> Column 1 </td>
      <td> Column 2 </td>
      <td> Column 3 </td>
      </tr>
      <table>
      

      Clear your index.html file and paste the code snippet above into the document. (If you have not been following the tutorial series, you can review instructions for setting up an index.html file in our tutorial Setting Up Your HTML Project.)

      Save and reload the file in the browser to check your results. (For instructions on loading the file in your browser, please visit this step of our tutorial on HTML Elements.)

      Your webpage should now have a table with three columns and two rows:

      3 columns, 2 rows table

      To add an additional row, add another <tr> element like so:

      <table>
      <tr> 
      <td> Column 1 </td>
      <td> Column 2 </td>
      <td> Column 3 </td>
      </tr>
      <tr> 
      <td> Column 1 </td>
      <td> Column 2 </td>
      <td> Column 3 </td>
      </tr>
      <tr> 
      <td> Column 1 </td>
      <td> Column 2 </td>
      <td> Column 3 </td>
      </tr>
      <table> 
      

      Save your results and check them in your browser. You should receive something like this:

      3 Columns and 3 Rows Table

      To add another column, try adding another table data <td> element inside each of the table row <tr> elements like so:

      <table>
      <tr> 
      <td> Column 1 </td>
      <td> Column 2 </td>
      <td> Column 3 </td>
      <td> Column 4 </td>
      </tr>
      <tr> 
      <td> Column 1 </td>
      <td> Column 2 </td>
      <td> Column 3 </td>
      <td> Column 4 </td>
      </tr>
      <tr> 
      <td> Column 1 </td>
      <td> Column 2 </td>
      <td> Column 3 </td>
      <td> Column 4 </td>
      </tr>
      <table>
      

      Save your results and check them in your browser. You should receive something like this:

      4 Columns, 3 Rows Table

      Tables can be styled by adding attributes to the <table> element. For example, you can add a border to the table with the border attribute like so:

      <table border=”1”>
      <tr> 
      <td> Row 1 </td>
      <td> Row 2 </td>
      <td> Row 3 </td>
      </tr>
      <tr> 
      <td> Row 1 </td>
      <td> Row 2 </td>
      <td> Row 3 </td>
      </tr>
      <table>
      

      Try adding the border attribute to your table and checking your results in the browser. (You can clear your index.html file and paste in the HTML code snippet above.) Save your file and load it in the browser. You should receive something like this:

      Table with Border

      You should now understand how to add tables to your webpage and how to customize the amount of rows and columns a table contains. Tables can also be used to arrange content on your web page. There are also many other attributes you can use to style your table. We’ll return to tables as a layout tool and explore their styling possibilities later on in this tutorial series when we begin building our website.



      Source link

      How To Fix Corrupted Tables in MySQL



      Part of the Series:
      How To Troubleshoot Issues in MySQL

      This guide is intended to serve as a troubleshooting resource and starting point as you diagnose your MySQL setup. We’ll go over some of the issues that many MySQL users encounter and provide guidance for troubleshooting specific problems. We will also include links to DigitalOcean tutorials and the official MySQL documentation that may be useful in certain cases.

      Occasionally, MySQL tables can become corrupted, meaning that an error has occurred and the data held within them is unreadable. Attempts to read from a corrupted table will usually lead to the server crashing.

      Some common causes of corrupted tables are:

      • The MySQL server stops in middle of a write.
      • An external program modifies a table that’s simultaneously being modified by the server.
      • The machine is shut down unexpectedly.
      • The computer hardware fails.
      • There’s a software bug somewhere in the MySQL code.

      If you suspect that one of your tables has been corrupted, you should make a backup of your data directory before troubleshooting or attempting to fix the table. This will help to minimize the risk of data loss.

      First, stop the MySQL service:

      • sudo systemctl stop mysql

      Then copy all of your data into a new backup directory. On Ubuntu systems, the default data directory is /var/lib/mysql/:

      • cp -r /var/lib/mysql /var/lib/mysql_bkp

      After making the backup, you’re ready to begin investigating whther the table is in fact corrupted. If the table uses the MyISAM storage engine, you can check whether it’s corrupted by running a CHECK TABLE statement from the MySQL prompt:

      A message will appear in this statement's output letting you know whether or not it's corrupted. If the MyISAM table is indeed corrupted, it can usually be repaired by issuing a REPAIR TABLE statement:

      Assuming the repair was successful, you will see a message like the following in your output:

      Output

      +--------------------------+--------+----------+----------+ | Table | Op | Msg_type | Msg_text | +--------------------------+--------+----------+----------+ | database_name.table_name | repair | status | OK | +--------------------------+--------+----------+----------+

      If the table is still corrupted, though, the MySQL documentation suggests a few alternative methods for repairing corrupted tables.

      On the other hand, if the corrupted table uses the InnoDB storage engine, then the process for repairing it will be different. InnoDB is the default storage engine in MySQL as of version 5.5, and it features automated corruption checking and repair operations. InnoDB checks for corrupted pages by performing checksums on every page it reads, and if it finds a checksum discrepancy it will automatically stop the MySQL server.

      There is rarely a need to repair InnoDB tables, as InnoDB features a crash recovery mechanism that can resolve most issues when the server is restarted. However, if you do encounter a situation where you need to rebuild a corrupted InnoDB table, the MySQL documentation recommends using the "Dump and Reload" method. This involves regaining access to the corrupted table, using the mysqldump utility to create a logical backup of the table, which will retain the table structure and the data within it, and then reloading the table back into the database.

      With that in mind, try restarting the MySQL service to see if doing so will allow you access to the server:

      • sudo systemctl restart mysql

      If the server remains crashed or otherwise inaccessible, then it may be helpful to enable InnoDB's force_recovery option. You can do this by editing the mysqld.cnf file:

      • sudo nano /etc/mysql/mysql.conf.d/mysqld.cnf

      In the [mysqld] section, add the following line:

      /etc/mysql/mysql.conf.d/mysqld.cnf

      . . .
      [mysqld]
      . . .
      innodb_force_recovery=1
      

      Save and close the file, and then try restarting the MySQL service again. If you can successfully access the corrupted table, use the mysqldump utility to dump your table data to a new file. You can name this file whatever you like, but here we'll name it out.sql:

      • mysqldump database_name table_name > out.sql

      Then drop the table from the database. To avoid having to reopen the MySQL prompt, you can use the following syntax:

      • mysql -u user -p --execute="DROP TABLE database_name.table_name"

      Following this, restore the table with the dump file you just created:

      • mysql -u user -p < out.sql

      Note that the InnoDB storage engine is generally more fault-tolerant than the older MyISAM engine. Tables using InnoDB can still be corrupted, but because of its auto-recovery features the risk of table corruption and crashes is decidedly lower.



      Source link