Primary key uses clustered index by default and unique key uses Non-clustered index.<\/li>\n<\/ul>\n![\"\"](\"https:\/\/www.wikitechy.com\/interview-questions\/wp-content\/uploads\/2022\/09\/unique-key-as-replacement-for-primary-key.jpg\")
<\/p>\n","protected":false},"excerpt":{"rendered":"
Both Keys are different. For Identifying each and every record in a table we use primary key. To apply additional uniqueness for other columns on the table we use Unique Key. Primary Keys are important for a table. Internal users use Primary Key whereas external users use unique key as it contains some meaningful information. […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"passster_activate_protection":false,"passster_protect_child_pages":"","passster_protection_type":"password","passster_password":"","passster_activate_overwrite_defaults":"","passster_headline":"","passster_instruction":"","passster_placeholder":"","passster_button":"","passster_id":"","passster_activate_misc_settings":"","passster_redirect_url":"","passster_hide":"no","passster_area_shortcode":"","gtb_hide_title":false,"gtb_wrap_title":false,"gtb_class_title":"","gtb_remove_headerfooter":false,"footnotes":""},"categories":[6547],"tags":[18677,18674,18678,18679,18682,18676,18675,18680,18681],"class_list":["post-4879","post","type-post","status-publish","format-standard","hentry","category-sql","tag-can-we-use-unique-key-as-primary-key","tag-difference-between-primary-key-and-unique-key","tag-difference-between-unique-key-and-primary-key","tag-foreign-key-and-primary-key","tag-how-many-null-values-in-unique-key","tag-primary-key-vs-unique-key","tag-primary-keys-vs-unique-keys","tag-unique-key-example","tag-unique-key-in-sql"],"yoast_head":"\n
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