Are there any best practices for creating a Like/Favourite feature in WordPress using custom MySQL tables and without any plugins?

Using WordPress’s wp_postmeta will help you a lot, instead of creating a new table. Functions like get_post_meta(), update_post_meta(), add_post_meta() etc, are readily available for use.

All you need is to create a meta_key (which in this case will be wp_likes) and the meta_value (number of likes will be stored), which can be easily retrieved using get_post_meta().

You can see the links below for references:

add_post_meta

get_post_meta

update_post_meta

delete_post_meta

Related Posts:

  1. Multipart/formatted MySQL query problem
  2. Are database queries created using WordPress filters protected from SQL injection?
  3. How do I see the mysql query generated by get_posts( $args )?
  4. how to insert missing tags into the posts through mySQL?
  5. I want to get on those users their meta value are like “AGENT” .. but this query is not working
  6. SQL query to delete users with multiple meta keys and comments
  7. How to make MySQL search queries with quotes
  8. How to display SQL query that ran in query?
  9. What SQL Query to do a simple find and replace
  10. Is there a way to list all used/unused WP templates?
  11. simple sql query on wp_postmeta very slow
  12. How to Use Wildcards in $wpdb Queries Using $wpdb->get_results & $wpdb->prepare?
  13. wpdb get posts by taxonomy SQL
  14. How many WordPress SQL Queries per page?
  15. SQL query equivalent to WP User Query
  16. WordPress creating excessive joins on meta_query with search
  17. cron job to auto delete posts of a specific post type older than x days
  18. Get posts by category with pure SQL query
  19. Delete duplicate rows from wordpress database where a column is duplicate in phpmyadmin
  20. Custom query to get terms from post ids
  21. Query WordPress database by registered date and role
  22. Get the timout value of a saved transient?
  23. Grouping related postmeta data via SQL query
  24. Mysql / WordPress killing my server with 80k users [closed]
  25. Slow meta_query with about 4 milion record on wp_postmeta
  26. Select User by Joining Multiple Meta Value Results
  27. mySQL query. ORDER BY meta_key
  28. Update slug (URL) of pending posts via phpMyAdmin
  29. My SQL function to change user_name
  30. You have an error in your SQL syntax – Help with query
  31. What’s wrong with my $wpdb prepare?
  32. MySQL variable in query
  33. how would I create a custom query to get all users, and a related post based on a postmeta field?
  34. Help with MySQL to $WPDB query
  35. SQL query to select posts from multiple categories
  36. Alter query with posts_clauses to retrieve NULL values last
  37. Order by summing multiple values
  38. sql select query in wordpress ‘page’ [closed]
  39. problem with sql query in wordpress plugin
  40. MySql Query very slow
  41. Attempt to improve WP search, can someone check my SQL query?
  42. Searching With Apostrophe
  43. wpdb query problem to access previous 3 days posts
  44. WordPress Query wp-terms SLOW
  45. I can’t figure out what’s wrong with this statement. $wpdb->query update
  46. Making a query to the DB using same parameters of loop
  47. wpdb COALESCE won’t work
  48. Custom Query – Based on user input
  49. Get posts from category with custom query
  50. Ideas how to search & replace post_content when string contains a newline?
  51. SQL query to set posts in bulk based on the post content
  52. Valid SQL query return empty
  53. mysql query – how to escape apostrophe?
  54. Query the WordPress database to get data together with replaced information
  55. $wpdb->prepare affecting the query?
  56. WordPress SQL search, how to handle SQL Injection?
  57. exclude pingbacks from wordpress SQL query
  58. Optimize slow SQL query for multiple meta values
  59. prepare function sql safe method
  60. Updating with $qpdb->query() always returns 0 rows affected
  61. WordPress SQL query to tag all posts containing a specific word on title
  62. mySQL queries are executed twice on wordpress website
  63. How to return count of custom post type posts with a specific custom field value via $wpdb?
  64. Select column name dynamically mySQL Query
  65. WordPress Mysql query and Duplicate
  66. How do I query for posts by custom meta and those that have been stickied?
  67. Help with Related Posts Function
  68. Change pure SQL database query to WordPress post query?
  69. How to delete all images from code in all post_content
  70. Cannot get sql request from Query object?
  71. Display data from phpMyAdmin with WordPress
  72. Delete oldest wordpress post (SQL query)
  73. Displaying data from custom table
  74. Get 2 meta values from meta key column
  75. SQL to Query the db and return all posts and it’s metas
  76. PHP Fatal error: Uncaught Error: Call to a member function insert() on null
  77. Nested select statements not working
  78. OR condition not working
  79. Trouble migrating custom post types from non-wordpress cms
  80. Speed up search query that searches in post meta?
  81. Fastest and most efficient SQL query to check if UID exists
  82. Performance of wp_get_attachment_image_srcset() and wp_get_attachment_image_url()
  83. How i make a custom sql query for Woocommerce
  84. $wpdb query for price in custom field value
  85. Run an update query in a function
  86. How to display a specific category using a custom Query in WordPress?
  87. Custom MySQL Query for Post and Post Meta
  88. Slow query when joining wp_posts with a lookup-table?
  89. Wpdb generates too many queries
  90. Mysql query and odd results
  91. learn to run wpdb class
  92. sql for querying post and their category
  93. Access Tables with number prefix
  94. SQL Query : how copy all tags of post into their post content in wordpress by sql query
  95. Where can I find the SQL to get the most used information by wordpress database?
  96. Custom Query for wp_posts using wp_postmeta
  97. 3 queries to update WordPress
  98. SQL Query to get post_id from wp_posts and and meta_key(s) from wp_postmeta
  99. Get stock by custom meta field on all Woocommerce variable products
  100. Batch Scanning and Deleting Empty WordPress Posts