How to run select query of post with category and tags?

1) Blank page in WordPress means, there is a fatal PHP error in your code. Also the or die() statement could cause the white page. You should not use or die() in production code, instead use try .. catch

2) Besides this I strongly discourage you from using mysqli_* functions in WordPress. Always use $wpdb for DB access!

3) Your query has some issues, but those will not cause the blank page but possibly incorrect results.

4) In this case you possibly want to use core WP functions instead. Like get_posts() and get_the_category()

Related Posts:

  1. Query posts from current year
  2. WordPress custom Query for Posts in Category display posts multiple times
  3. How can I setup a relationship using categories in WordPress?
  4. Migrate posts from category and sub-category via SQL
  5. SQL Bulk Move old posts by one author to another category
  6. How to display only one category in a custom post type?
  7. Export all posts to import as product items
  8. Get current taxonomy and display query accordingly
  9. AJAX load more posts not using correct category and repeating the same few posts
  10. Querying posts from current category, using a variable as array argument
  11. Query posts from newest category
  12. Query post category & remove any post id
  13. Sort post by category using HTML Select tag
  14. Special Query: Title, Terms, Content – %LIKE%
  15. The page that displays Posts on homepage
  16. Sort Posts Alphabetically Based on Specific Category (Divi)
  17. Change permalinks in posts via SQL
  18. Batch Scanning and Deleting Empty WordPress Posts
  19. How to get a list of all posts and their categories?
  20. Including categories in search results
  21. Count how many posts in category
  22. Custom Single Post By Category
  23. Convert custom fields to post categories
  24. Using $wpdb to query posts with meta value containing current post_id
  25. how to get permalink using sql
  26. Show One Category on Post
  27. Order post by year DESC and month ASC
  28. How can I display a specific user’s first published post?
  29. Do I use custom post type or something else?
  30. What Defines What Category A Post Picks (if in multiple)
  31. Limit function to specific post category
  32. Show all post titles
  33. Add Category name to Post Title (h1)
  34. Posts are not showing up on particular category
  35. How to display related posts by subcategory and not parent category
  36. Category Template: Need to display different content on first page of archives
  37. Get posts by name and taxonomy term
  38. Get Posts that are in the current month or later
  39. Display post category in foreach loop with category link
  40. Extracting post categories
  41. Get Meta Key Value While Saving Post
  42. How to limit posts by category
  43. How to verify wp user password by sql query in wp? [closed]
  44. Get ALL post ID’s export list (Only id’s. Php or sql not important )
  45. Get user categories with most posts in it
  46. Using ajax on editing a category edit page?
  47. How to make multiple sections in home pulling posts category wise?
  48. How to get posts and comments amount per hour, per year and per month?
  49. How to get subcategories from category slug?
  50. Change default category when I publish a post
  51. Loop doesn’t exclude the specified category in home page
  52. Post Image not displaying in category view
  53. Can’t get full post title if there a spaces in title
  54. Parent category / child category posts
  55. Exclude post category in a blog page
  56. WP_Query of Category Not Showing First Post
  57. How to make posts being uncategorized
  58. How to display a single(current) post from a category
  59. displaying the categories post
  60. What’s a theme that properly handles previews of different types of posts?
  61. Custom Select Query – Selecting the Year?
  62. WordPress, custom post type and posts query help!
  63. How to add content above footer in posts from specific category
  64. WordPress – When visiting a `single post/ single.php` my category menu item link becomes active
  65. WordPress Query – Display 5 posts (same post type), each from a given tag
  66. How to Create another Page Category like the “Post” and “Pages”
  67. Ignore posts content in the posts queries for internal linking
  68. How to create a button to filter posts (list) by meta value
  69. Is there a way to save different data when USER interacts with the same POST?
  70. How to display particular categorie’s post which associated to specific user?
  71. Display Specific Categories posts on the home page
  72. show only one category and filter by tag
  73. Code to display random ordered posts in Categories across pages [duplicate]
  74. Category posts show on local install, they do not show on live server
  75. How can I exclude only a specific sub category post from category display?
  76. how to print total number of posts filtered by category?
  77. Is it possible to remove actual post pages in wordpress but keep them in categories
  78. Need help with hiding an image within a post in a category
  79. WordPress not showing recent posts
  80. How to get post count including nested categories
  81. How to filter out post from a category not its subcategory in wordpress dashboard
  82. Export Posts with specific custom fields by sql
  83. How can I display a specific number of post in a category via a url
  84. how to chang preview of list of articles of one category?
  85. Advanced Post Display/Pagination/Ordering
  86. Can’t create posts with WP DB Abstraction Plugin
  87. Post of a specific category – not to be seen in paging previous/next post
  88. How to show main category related to that post
  89. Display selected category on post page
  90. Make assigning post to a specific category equivalent to assigning it to all categories
  91. How to use in_category?
  92. About number of posts in selected category
  93. WP_Query retrieve custom posts but not the post showing
  94. Category page shows “No Posts” but I do have two assigned
  95. Exclude a ‘portfolio’ custom category?
  96. ‘get_previous_post’ in same category returning (!empty) when no previous post in category exists
  97. excerpt in template for specific page
  98. Only show posts belonging to multiple cateogries at same time
  99. Wrap posts from a category in HTML
  100. How to make WP_Query faster when getting a post from one year ago?