I want to create a filter for the query string is this possible?

To at least answer the title of your question, the pre_get_posts filter may be useful. From the Codex:

This hook is called after the query variable object is created, but
before the actual query is run.

The pre_get_posts action gives developers access to the $query object
by reference (any changes you make to $query are made directly to the
original object – no return value is necessary).

Related Posts:

  1. Issue with using add_rewrite_rule() for post querying custom fields
  2. Rewrite rule for query params
  3. Add rewrite rule for archive search
  4. WordPress add_query_arg from ajax and make url friendly
  5. Sort loop with query in the link
  6. Rewrite Query_Var URL Parameter with Slug
  7. How to Optimize WP site for millions of posts
  8. Differences between wpdb->get_results() and wpdb->query()
  9. Get Terms by IDs with IDs order
  10. Using WordPress public query variables
  11. How many WordPress SQL Queries per page?
  12. Slow wp_enqueue_media()
  13. Advanced Custom Fields – Query Efficiency
  14. Why does wordpress still strip my query var?
  15. How to display lastest post date in the homepage?
  16. $query->query_var[‘post_type’] not set for pages
  17. How to tell if $query_var isset?
  18. Get IDs of posts currently visible on archive
  19. Get posts by category with pure SQL query
  20. can’t get query to order posts by acf datepicker
  21. Sorting Grids with Essential Grid and Events Manger
  22. The use of including upgrade.php when building custom queries
  23. Custom query to get terms from post ids
  24. Get the timout value of a saved transient?
  25. WordPress query by category, sorted by custom field
  26. Does meta_query work within get_posts array?
  27. Slow meta_query with about 4 milion record on wp_postmeta
  28. How to show more than 5 posts?
  29. Deleting data from a custom table in WordPress
  30. WordPress Find Duplicate Post By Content
  31. WP Query Sort by meta value (date)
  32. How to optimize my query filtering out unwanted data?
  33. mySQL query. ORDER BY meta_key
  34. Remove posts from query for events whose start date has passed
  35. how to query multiple categories in wordpress?
  36. Disable the MySQL query in the main query
  37. Strange string in console from wpdb query
  38. Update slug (URL) of pending posts via phpMyAdmin
  39. How can I get the query that would be run for the archive page?
  40. Query metas (and not : query posts by metas)
  41. Select query for a login
  42. What’s wrong with my $wpdb prepare?
  43. pre_get_posts : ‘post__not_in’ doesn’t work with global variable
  44. where should I reset query after using get_results?
  45. Getting post data from private page
  46. Exclude featured image and custom field from this get_attachment query
  47. Protect sequence of pages with same password for each of two groups of users
  48. wpdb print all post meta
  49. Form and custom query problem
  50. Export Specific User data without plugin
  51. Query to get number of posts last week
  52. Exclude categories from the_category();
  53. How can i show all categories using wp query?
  54. All in One Calendar Plugin Custom Post Type Query [closed]
  55. Get Posts from Last 24 hours and Sort them via GD Star Rating
  56. Query returning same results even though the ID changes
  57. Why my query ‘REPLACE INTO…’ does not work?
  58. Restrict query to last day with posts
  59. Custom query object with Simple-Fields custom date field
  60. How to read the value of a WordPress $query associative array (hash) key
  61. Query posts based on previous query
  62. Waypoints + infinite scroll with custom query
  63. Customizing the_tags output?
  64. Querying with WP query using meta key price
  65. Re-sort get_posts query results
  66. How do I get all results from my query
  67. Taxonomy filter under Polylang
  68. WordPress Mysql query and Duplicate
  69. How to create an overview of posts with the same tag?
  70. create a link to a random post within the current category
  71. How to “orderby” the first array in a meta_query that uses multiply keys?
  72. Pagination not working on custom post types with rewrite slug
  73. JetEngine Query Builder – order by value from repeater
  74. Change pure SQL database query to WordPress post query?
  75. Filter orders by modify date
  76. How to add url parameter to every search query in SearchWp?
  77. custom sorting media with multiple filters – error: not unique table/alias: wp_postmeta
  78. How can I get posts by 2 meta keys, prioritising one of them?
  79. Heavy meta query causing SQL crash
  80. SQL query to list all posts of specific post type with a specific set of associated postmeta values as a column
  81. Sort by postmeta on when searching
  82. Pulling an ACF into a query
  83. Speed up search query that searches in post meta?
  84. modifying main query to query for ranges e.g. from 1999 to 2016
  85. Querying users by meta value and getting a strange answer
  86. Problem on wpdb queries, wp_insert_post, wp_insert_user etc. The query runs twice
  87. Using cron for multiple queries
  88. very slow wordpress query with default query
  89. Multilingual WordPress page – using URL to determine language?
  90. Custom Query problem access the values
  91. Set posts per page for parent category and it’s all children
  92. Exclude sticky posts from query
  93. If more than 1 image show post link?
  94. WP_Query with checkbox meta_query – WordPress [duplicate]
  95. How to query different categories on index?
  96. How to specify what kind of is_single post?
  97. Can’t See Media Queries with Inspect Tool [closed]
  98. Print data from wordpress sql query
  99. Can I create my own query in wordpress with traditional methods?
  100. How to figure out correct wp_options to have autoload=’yes’
techhipbettruvabetnorabahisbahis forumutaraftarium24eduedusedusedueduedusedueduedusedu