\u672c\u6587\u8be6\u7ec6\u63a2\u8ba8 MySQL \u57fa\u7840\u77e5\u8bc6\u7684\u5404\u4e2a\u65b9\u9762\uff0c\u6211\u4eec\u5c06\u7ec6\u5316\u6bcf\u4e2a\u77e5\u8bc6\u70b9\uff0c\u8bb2\u89e3\u76f8\u5173\u539f\u7406\u3001\u4f7f\u7528\u65b9\u6cd5\u4ee5\u53ca\u5e38\u89c1\u7684\u6700\u4f73\u5b9e\u8df5\u3002<\/p>\r\n\r\n\r\n\r\n
apt<\/code>\u3001yum<\/code>\uff09\u6216\u76f4\u63a5\u4e0b\u8f7d\u5b89\u88c5\u5305\u3002\u5b89\u88c5\u540e\uff0c\u4e3b\u8981\u7684\u914d\u7f6e\u6587\u4ef6\u662f my.cnf<\/code>\uff08Linux\uff09\u6216 my.ini<\/code>\uff08Windows\uff09\u3002\u5e38\u89c1\u7684\u914d\u7f6e\u9879\u6709\uff1a<\/li>\r\n\r\n\r\n\r\ninnodb_buffer_pool_size<\/code>\uff1a\u51b3\u5b9a InnoDB \u5b58\u50a8\u5f15\u64ce\u7684\u6570\u636e\u7f13\u5b58\u5927\u5c0f\u3002<\/li>\r\n\r\n\r\n\r\nmax_connections<\/code>\uff1a\u8bbe\u7f6e\u6700\u5927\u5141\u8bb8\u7684\u8fde\u63a5\u6570\u3002<\/li>\r\n\r\n\r\n\r\nquery_cache_size<\/code>\uff1a\u8bbe\u7f6e\u67e5\u8be2\u7f13\u5b58\u7684\u5927\u5c0f\uff08\u6ce8\u610f\uff1a\u5728 MySQL 8.0 \u7248\u672c\u4e2d\u5df2\u88ab\u79fb\u9664\uff09\u3002<\/li>\r\n\r\n\r\n\r\ntmp_table_size<\/code> \u548c max_heap_table_size<\/code>\uff1a\u8bbe\u7f6e\u4e34\u65f6\u8868\u7684\u5927\u5c0f\u9650\u5236\u3002 \u914d\u7f6e\u6587\u4ef6\u4fee\u6539\u540e\u9700\u8981\u91cd\u542f MySQL \u670d\u52a1\uff0c\u547d\u4ee4\u4e3a\uff1a<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n sudo systemctl restart mysql<\/code><\/pre>\r\n\r\n\r\n\r\n\r\n- MySQL \u5ba2\u6237\u7aef\u4e0e\u547d\u4ee4\u884c\u64cd\u4f5c<\/strong>
\u901a\u8fc7 MySQL \u5ba2\u6237\u7aef\u547d\u4ee4\u884c\u8fdb\u884c\u57fa\u672c\u64cd\u4f5c\uff1a<\/li>\r\n\r\n\r\n\r\n- \u8fde\u63a5 MySQL\uff1a
bash mysql -u root -p<\/code><\/li>\r\n\r\n\r\n\r\n- \u9000\u51fa MySQL \u5ba2\u6237\u7aef\uff1a
bash EXIT;<\/code><\/li>\r\n\r\n\r\n\r\n- \u67e5\u770b\u5f53\u524d\u6570\u636e\u5e93\uff1a
sql SELECT DATABASE();<\/code><\/li>\r\n\r\n\r\n\r\n- \u663e\u793a\u6240\u6709\u6570\u636e\u5e93\uff1a
sql SHOW DATABASES;<\/code><\/li>\r\n\r\n\r\n\r\n- \u4f7f\u7528\u6307\u5b9a\u6570\u636e\u5e93\uff1a
sql USE database_name;<\/code><\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n2. \u6570\u636e\u5e93\u4e0e\u8868\u7ba1\u7406<\/strong><\/h3>\r\n\r\n\r\n\r\n\r\n- \u521b\u5efa\u6570\u636e\u5e93\u4e0e\u8868<\/strong><\/li>\r\n\r\n\r\n\r\n
- \u521b\u5efa\u6570\u636e\u5e93\uff1a
sql CREATE DATABASE database_name;<\/code><\/li>\r\n\r\n\r\n\r\n- \u521b\u5efa\u8868\uff1a
sql CREATE TABLE table_name ( column1_name column1_type, column2_name column2_type, ... );<\/code>
\u793a\u4f8b\uff1a<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n CREATE TABLE users (\r\n id INT AUTO_INCREMENT PRIMARY KEY,\r\n username VARCHAR(50) NOT NULL,\r\n email VARCHAR(100),\r\n created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP\r\n );<\/code><\/pre>\r\n\r\n\r\n\r\n\r\n- \u5220\u9664\u6570\u636e\u5e93\u4e0e\u8868<\/strong><\/li>\r\n\r\n\r\n\r\n
- \u5220\u9664\u8868\uff1a
sql DROP TABLE table_name;<\/code><\/li>\r\n\r\n\r\n\r\n- \u5220\u9664\u6570\u636e\u5e93\uff1a
DROP DATABASE database_name;<\/code><\/li>\r\n\r\n\r\n\r\n- \u4fee\u6539\u8868\u7ed3\u6784<\/strong><\/li>\r\n\r\n\r\n\r\n
- \u6dfb\u52a0\u5217\uff1a
sql ALTER TABLE table_name ADD column_name column_type;<\/code><\/li>\r\n\r\n\r\n\r\n- \u5220\u9664\u5217\uff1a
sql ALTER TABLE table_name DROP COLUMN column_name;<\/code><\/li>\r\n\r\n\r\n\r\n- \u4fee\u6539\u5217\uff1a
ALTER TABLE table_name MODIFY COLUMN column_name new_column_type;<\/code><\/li>\r\n\r\n\r\n\r\n- \u6570\u636e\u7c7b\u578b<\/strong><\/li>\r\n\r\n\r\n\r\n
- \u6570\u503c\u7c7b\u578b<\/strong>\uff1a\r\n
\r\nINT<\/code>: \u7528\u4e8e\u5b58\u50a8\u6574\u6570\uff0c\u652f\u6301\u7b26\u53f7\u548c\u65e0\u7b26\u53f7\u6574\u6570\uff0c\u8303\u56f4\u6839\u636e\u5927\u5c0f\u4e0d\u540c\uff08\u5982 INT(11)<\/code>\uff09\u3002<\/li>\r\n\r\n\r\n\r\nFLOAT<\/code> \u548c DOUBLE<\/code>: \u7528\u4e8e\u5b58\u50a8\u6d6e\u52a8\u7684\u5c0f\u6570\u3002FLOAT<\/code> \u7cbe\u5ea6\u8f83\u4f4e\uff0cDOUBLE<\/code> \u7cbe\u5ea6\u8f83\u9ad8\u3002<\/li>\r\n<\/ul>\r\n<\/li>\r\n\r\n\r\n\r\n- \u5b57\u7b26\u4e32\u7c7b\u578b<\/strong>\uff1a\r\n
\r\nVARCHAR(n)<\/code>: \u53ef\u53d8\u957f\u5ea6\u7684\u5b57\u7b26\u4e32\uff0c\u6700\u591a\u5b58\u50a8 n<\/code> \u4e2a\u5b57\u7b26\u3002<\/li>\r\n\r\n\r\n\r\nTEXT<\/code>: \u7528\u4e8e\u5b58\u50a8\u957f\u6587\u672c\u6570\u636e\uff0c\u6700\u591a\u53ef\u4ee5\u5b58\u50a8 65,535 \u5b57\u7b26\u3002<\/li>\r\n<\/ul>\r\n<\/li>\r\n\r\n\r\n\r\n- \u65e5\u671f\u65f6\u95f4\u7c7b\u578b<\/strong>\uff1a\r\n
\r\nDATE<\/code>: \u5b58\u50a8\u65e5\u671f\uff08\u5982 2023-05-12<\/code>\uff09\u3002<\/li>\r\n\r\n\r\n\r\nDATETIME<\/code>: \u5b58\u50a8\u65e5\u671f\u548c\u65f6\u95f4\uff08\u5982 2023-05-12 14:30:00<\/code>\uff09\u3002<\/li>\r\n\r\n\r\n\r\nTIMESTAMP<\/code>: \u5b58\u50a8\u4ece 1970 \u5e74 1 \u6708 1 \u65e5\u5f00\u59cb\u7684\u79d2\u6570\uff0c\u5e38\u7528\u4e8e\u8868\u793a\u4e8b\u4ef6\u53d1\u751f\u7684\u65f6\u95f4\u3002<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n3. SQL \u57fa\u7840\u64cd\u4f5c<\/strong><\/h3>\r\n\r\n\r\n\r\n\r\n- SELECT \u67e5\u8be2<\/strong><\/li>\r\n\r\n\r\n\r\n
- \u9009\u62e9\u6240\u6709\u5217\uff1a
sql SELECT * FROM users;<\/code><\/li>\r\n\r\n\r\n\r\n- \u9009\u62e9\u6307\u5b9a\u5217\uff1a
SELECT id, username FROM users;<\/code><\/li>\r\n\r\n\r\n\r\n- WHERE \u6761\u4ef6\u67e5\u8be2<\/strong>
\u4f7f\u7528 WHERE<\/code> \u8fdb\u884c\u6570\u636e\u7b5b\u9009\uff1a<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n SELECT * FROM users WHERE username = 'john';<\/code><\/pre>\r\n\r\n\r\n\r\n\r\n- \u4f7f\u7528\u903b\u8f91\u8fd0\u7b97\u7b26\uff1a
AND<\/code>, OR<\/code>\uff1a<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n SELECT * FROM users WHERE age > 25 AND gender = 'M';<\/code><\/pre>\r\n\r\n\r\n\r\n\r\n- INSERT \u63d2\u5165\u6570\u636e<\/strong>
\u5411\u8868\u4e2d\u63d2\u5165\u6570\u636e\uff1a<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n INSERT INTO users (username, email) VALUES ('johndoe', 'john@example.com');<\/code><\/pre>\r\n\r\n\r\n\r\n\r\n- UPDATE \u66f4\u65b0\u6570\u636e<\/strong>
\u66f4\u65b0\u8868\u4e2d\u73b0\u6709\u7684\u6570\u636e\uff1a<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n UPDATE users SET email = 'newemail@example.com' WHERE username = 'johndoe';<\/code><\/pre>\r\n\r\n\r\n\r\n\r\n- DELETE \u5220\u9664\u6570\u636e<\/strong>
\u5220\u9664\u6ee1\u8db3\u6761\u4ef6\u7684\u6570\u636e\uff1a<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n DELETE FROM users WHERE username = 'johndoe';<\/code><\/pre>\r\n\r\n\r\n\r\n4. \u6392\u5e8f\u4e0e\u5206\u7ec4<\/strong><\/h3>\r\n\r\n\r\n\r\n\r\n- ORDER BY \u6392\u5e8f<\/strong>
\u6309\u7167\u6307\u5b9a\u5217\u6392\u5e8f\uff1a<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n SELECT * FROM users ORDER BY created_at DESC;<\/code><\/pre>\r\n\r\n\r\n\r\n\r\n- GROUP BY \u5206\u7ec4<\/strong>
\u5bf9\u6570\u636e\u8fdb\u884c\u5206\u7ec4\u5e76\u4f7f\u7528\u805a\u5408\u51fd\u6570\uff08\u5982 COUNT<\/code>\u3001SUM<\/code> \u7b49\uff09\uff1a<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n SELECT COUNT(*) AS total_users FROM users GROUP BY gender;<\/code><\/pre>\r\n\r\n\r\n\r\n\r\n- HAVING \u5b50\u53e5<\/strong>
\u7528\u4e8e\u8fc7\u6ee4 GROUP BY<\/code> \u5206\u7ec4\u540e\u7684\u6570\u636e\uff1a<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n SELECT gender, COUNT(*) AS total_users\r\n FROM users\r\n GROUP BY gender\r\n HAVING COUNT(*) > 5;<\/code><\/pre>\r\n\r\n\r\n\r\n5. \u5e38\u89c1\u7ea6\u675f<\/strong><\/h3>\r\n\r\n\r\n\r\n\r\n- \u4e3b\u952e\uff08PRIMARY KEY\uff09<\/strong>
\u4e3b\u952e\u7ea6\u675f\u4fdd\u8bc1\u6570\u636e\u7684\u552f\u4e00\u6027\u548c\u975e\u7a7a\u6027\u3002<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n CREATE TABLE users (\r\n id INT PRIMARY KEY,\r\n username VARCHAR(50) NOT NULL\r\n );<\/code><\/pre>\r\n\r\n\r\n\r\n\r\n- \u5916\u952e\uff08FOREIGN KEY\uff09<\/strong>
\u5916\u952e\u7528\u4e8e\u5728\u8868\u4e4b\u95f4\u5efa\u7acb\u5173\u8054\uff1a<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n CREATE TABLE orders (\r\n order_id INT PRIMARY KEY,\r\n user_id INT,\r\n FOREIGN KEY (user_id) REFERENCES users(id)\r\n );<\/code><\/pre>\r\n\r\n\r\n\r\n\r\n- \u552f\u4e00\u7ea6\u675f\uff08UNIQUE\uff09<\/strong>
\u4fdd\u8bc1\u5b57\u6bb5\u503c\u552f\u4e00\uff1a<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n CREATE TABLE users (\r\n id INT PRIMARY KEY,\r\n email VARCHAR(100) UNIQUE\r\n );<\/code><\/pre>\r\n\r\n\r\n\r\n\r\n- \u975e\u7a7a\u7ea6\u675f\uff08NOT NULL\uff09<\/strong>
\u5f3a\u5236\u5217\u4e0d\u80fd\u4e3a\u7a7a\uff1a<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n CREATE TABLE users (\r\n id INT PRIMARY KEY,\r\n username VARCHAR(50) NOT NULL\r\n );<\/code><\/pre>\r\n\r\n\r\n\r\n6. \u7d22\u5f15<\/strong><\/h3>\r\n\r\n\r\n\r\n\r\n- \u521b\u5efa\u7d22\u5f15<\/strong>
\u521b\u5efa\u666e\u901a\u7d22\u5f15\uff1a<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n CREATE INDEX idx_username ON users (username);<\/code><\/pre>\r\n\r\n\r\n\r\n\u521b\u5efa\u552f\u4e00\u7d22\u5f15\uff1a<\/p>\r\n\r\n\r\n\r\n
CREATE UNIQUE INDEX idx_email ON users (email);<\/code><\/pre>\r\n\r\n\r\n\r\n\r\n- \u7d22\u5f15\u7684\u4f5c\u7528<\/strong>
\u7d22\u5f15\u7528\u4e8e\u52a0\u901f\u67e5\u8be2\uff0c\u4f46\u4f1a\u5f71\u54cd\u6570\u636e\u63d2\u5165\u3001\u66f4\u65b0\u548c\u5220\u9664\u7684\u6027\u80fd\u3002\u5728\u5927\u578b\u6570\u636e\u8868\u4e2d\uff0c\u5408\u7406\u521b\u5efa\u7d22\u5f15\u53ef\u4ee5\u663e\u8457\u63d0\u9ad8\u67e5\u8be2\u6548\u7387\u3002<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n\u603b\u7ed3<\/h3>\r\n\r\n\r\n\r\n
\u8fd9\u4e00\u90e8\u5206\u4ecb\u7ecd\u4e86 MySQL \u7684\u6838\u5fc3\u57fa\u7840\uff0c\u6d89\u53ca\u6570\u636e\u5e93\u4e0e\u8868\u7684\u7ba1\u7406\u3001SQL \u57fa\u672c\u64cd\u4f5c\u4ee5\u53ca\u5e38\u89c1\u7ea6\u675f\u548c\u7d22\u5f15\u7684\u4f7f\u7528\u3002\u901a\u8fc7\u7406\u89e3\u548c\u638c\u63e1\u8fd9\u4e9b\u5185\u5bb9\uff0c\u4f60\u5c06\u80fd\u591f\u9ad8\u6548\u5730\u7ba1\u7406\u548c\u64cd\u4f5c MySQL \u6570\u636e\u5e93\u3002<\/p>\r\n","protected":false},"excerpt":{"rendered":"
\u672c\u90e8\u5206\u5c06\u5e2e\u52a9\u4f60\u638c\u63e1 MySQL \u57fa\u7840\uff0c\u5305\u62ec\u6570\u636e\u5e93\u7ba1\u7406\u3001\u8868\u7ba1\u7406\u3001SQL \u67e5\u8be2\u64cd\u4f5c\u548c\u5e38\u89c1\u6570\u636e\u7c7b\u578b\u3002\u901a\u8fc7\u5bf9 MySQL \u5b89\u88c5\u914d\u7f6e\u3001\u6570\u636e\u7ea6\u675f\u548c\u7d22\u5f15\u7684\u8be6\u7ec6\u8bb2\u89e3\uff0c\u4f60\u5c06\u6253\u4e0b\u575a\u5b9e\u7684 MySQL \u4f7f\u7528\u57fa\u7840\uff0c\u4e3a\u6df1\u5165\u5b66\u4e60 MySQL \u63d0\u4f9b\u6709\u529b\u652f\u6301\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35],"tags":[],"class_list":["post-1637","post","type-post","status-publish","format-standard","hentry","category-mysql"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/1637","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=1637"}],"version-history":[{"count":2,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/1637\/revisions"}],"predecessor-version":[{"id":1649,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/1637\/revisions\/1649"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=1637"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=1637"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=1637"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}