{"id":11086,"date":"2024-03-14T13:23:17","date_gmt":"2024-03-14T13:23:17","guid":{"rendered":"https:\/\/www.silicloud.com\/blog\/how-to-set-foreign-keys-in-a-database-table\/"},"modified":"2025-08-04T07:26:16","modified_gmt":"2025-08-04T07:26:16","slug":"how-to-set-foreign-keys-in-a-database-table","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/blog\/how-to-set-foreign-keys-in-a-database-table\/","title":{"rendered":"How to Set Database Foreign Keys"},"content":{"rendered":"<p>When setting foreign keys for a database table, it is necessary to use the FOREIGN KEY constraint. Below is an example SQL statement for creating a database table with a foreign key.<\/p>\n<pre class=\"post-pre\"><code><span class=\"hljs-keyword\">CREATE<\/span> <span class=\"hljs-keyword\">TABLE<\/span> \u8868\u540d (\r\n    \u5217<span class=\"hljs-number\">1<\/span> \u6570\u636e\u7c7b\u578b,\r\n    \u5217<span class=\"hljs-number\">2<\/span> \u6570\u636e\u7c7b\u578b,\r\n    \u5217<span class=\"hljs-number\">3<\/span> \u6570\u636e\u7c7b\u578b,\r\n    <span class=\"hljs-keyword\">FOREIGN<\/span> KEY (\u5916\u952e\u5217) <span class=\"hljs-keyword\">REFERENCES<\/span> \u53e6\u4e00\u4e2a\u8868\u540d(\u5173\u8054\u5217)\r\n);\r\n<\/code><\/pre>\n<p>In the example above, the foreign key column is the column in the current table that contains the foreign key, the other table name is the name of the other table to be related, and the join column is the column used for the join in the other table.<\/p>\n<p>It is important to note that before setting a foreign key, it is necessary to ensure that the referenced column is unique and has already been indexed. Additionally, it is also important to ensure that the data type of the referenced column matches the data type of the foreign key column.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>When setting foreign keys for a database table, it is necessary to use the FOREIGN KEY constraint. Below is an example SQL statement for creating a database table with a foreign key. CREATE TABLE \u8868\u540d ( \u52171 \u6570\u636e\u7c7b\u578b, \u52172 \u6570\u636e\u7c7b\u578b, \u52173 \u6570\u636e\u7c7b\u578b, FOREIGN KEY (\u5916\u952e\u5217) REFERENCES \u53e6\u4e00\u4e2a\u8868\u540d(\u5173\u8054\u5217) ); In the example above, the foreign key [&hellip;]<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","footnotes":""},"categories":[1],"tags":[2476,1935,14153,9382,3241],"class_list":["post-11086","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-database-constraints","tag-database-design","tag-database-foreign-keys","tag-relational-database","tag-sql-foreign-keys"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v21.5 (Yoast SEO v21.5) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>How to Set Database Foreign Keys - 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