{"id":39,"date":"2020-12-28T19:11:21","date_gmt":"2020-12-28T11:11:21","guid":{"rendered":"https:\/\/www.52dixiaowo.com\/database\/?p=39"},"modified":"2021-09-08T11:16:42","modified_gmt":"2021-09-08T03:16:42","slug":"ddl-%e6%93%8d%e4%bd%9c%e6%95%b0%e6%8d%ae%e5%ba%93%e5%92%8c%e8%a1%a8","status":"publish","type":"post","link":"https:\/\/www.52dixiaowo.com\/db\/post-39.html","title":{"rendered":"DDL — \u64cd\u4f5c\u6570\u636e\u5e93\u548c\u8868"},"content":{"rendered":"\n

1.\u6570\u636e\u5e93\u7684\u589e\u5220\u6539\u67e5\uff0c\u4e0e\u4f7f\u7528<\/h4>\n\n\n\n

1.\u67e5\u770b\u6240\u6709\u6570\u636e\u5e93\uff1a<\/h5>\n\n\n\n
show databases;<\/code><\/pre>\n\n\n\n
2.\u521b\u5efa\u6570\u636e\u5e93\uff1a\uff08\u5047\u8bbe\u6570\u636e\u5e93\u540d mytest )<\/h5>\n\n\n\n
create database mytest;<\/code><\/pre>\n\n\n\n
\u5982\u9700\u6307\u5b9a\u5b57\u7b26\u96c6\uff0c\u52a0  character set \u5b57\u7b26\u96c6\u540d\u79f0<\/p>\n\n\n\n
\u4e00\u822c\u5728\u521b\u5efa\u65f6\uff0c\u90fd\u5e94\u8be5\u6307\u5b9a\u5b57\u7b26\u96c6\u3002\u6bd4\u5982 utf8mb4\uff0c\u540c\u65f6\u9700\u8981\u5224\u65ad\u662f\u5426\u5df2\u5b58\u5728\u6570\u636e\u5e93<\/p>\n\n\n\n
\u6bd4\u5982 create database if not exists mytest character set utf8mb4;<\/p>\n\n\n\n
3.\u67e5\u770b\u67d0\u4e2a\u6570\u636e\u5e93\u521b\u5efa\u7684\u8bed\u53e5\uff0c\u7f16\u7801\uff08\u5047\u8bbe\u4e3a mytest)<\/h5>\n\n\n\n
show create database mytest;<\/code><\/pre>\n\n\n\n
4.\u5220\u9664\u6570\u636e\u5e93\uff1a\uff08\u5047\u8bbe\u6570\u636e\u5e93\u540d mytest\uff09<\/h5>\n\n\n\n
drop database mytest;<\/code><\/pre>\n\n\n\n
5.\u4fee\u6539\u6570\u636e\u5e93\u7684\u7f16\u7801\uff0c\uff08\u5047\u8bbe\u4e3a mytest)<\/h5>\n\n\n\n
alter database mytest character set gbk;<\/code><\/pre>\n\n\n\n
6.\u9009\u7528\u6570\u636e\u5e93\uff1a\uff08\u5047\u8bbe\u6570\u636e\u5e93\u540d mytest )<\/h5>\n\n\n\n
use mytest;<\/code><\/pre>\n\n\n\n
\u67e5\u770b\u6b63\u5728\u9009\u7528\u7684\u6570\u636e\u5e93\uff1aselect database();<\/p>\n\n\n\n
2.\u6570\u636e\u8868\u7684\u589e\u5220\u6539\u67e5<\/h4>\n\n\n\n
1.\u67e5\u770b\u6240\u6709\u8868\uff1a\uff08\u4f60\u5fc5\u987b\u5148\u9009\u7528\u67d0\u4e2a\u6570\u636e\u5e93\uff0c\u624d\u53ef\u4ee5\u5bf9\u8868\u64cd\u4f5c\uff09<\/h5>\n\n\n\n
show tables;<\/code><\/pre>\n\n\n\n
2.\u521b\u5efa\u8868\uff1a\uff08\u5047\u8bbe\u8868\u540d student\uff0c\u6709 name \u548c age 2\u4e2a\u5c5e\u6027\uff09<\/h5>\n\n\n\n
 create table student(\n      name varchar(10),\n      age int(10)\n     );<\/code><\/pre>\n\n\n\n
\u5982\u679c\u9700\u8981\u62f7\u8d1d\u67d0\u4e2a\u5df2\u6709\u7684\u8868\u7684\u7ed3\u6784\uff0c\u5219\u52a0\u4e0a \u201c like \u73b0\u6709\u7684\u8868\u540d \u201d<\/p>\n\n\n\n
3.\u67e5\u770b\u521b\u5efa\u8868\u8bed\u53e5\uff0c\u7f16\u7801\uff0c\u5f15\u64ce\u7b49<\/h5>\n\n\n\n
\u67e5\u770b\u67d0\u4e2a\u8868\u7684\u521b\u5efa\u8bed\u53e5\uff08\u5047\u8bbe\u4e3a student)<\/p>\n\n\n\n
show create table student;<\/code><\/pre>\n\n\n\n
4.\u5220\u9664\u8868\uff1a\uff08\u5047\u8bbe\u8868\u540d student\uff09<\/h5>\n\n\n\n
drop table student;<\/code><\/pre>\n\n\n\n
5.\u4fee\u6539\u6570\u636e\u8868\uff0c\u7684\u7f16\u7801<\/h5>\n\n\n\n
\u4fee\u6539\u67d0\u4e2a\u8868\u7684\u7f16\u7801\uff0c\uff08\u5047\u8bbe\u4e3a student)<\/p>\n\n\n\n
alter table student character set gbk;<\/code><\/pre>\n\n\n\n
6.\u4fee\u6539\u8868\u540d\uff0c\uff08 student \u662f\u65e7\u8868\u540d\uff0cstu \u662f\u65b0\u8868\u540d\uff09<\/h5>\n\n\n\n
alter table student rename to stu;<\/code><\/pre>\n\n\n\n
7.\u6570\u636e\u8868\u7ed3\u6784\u7684\u589e\u5220\u6539\u67e5<\/h5>\n\n\n\n
\u67e5\u8be2\u8868\u7ed3\u6784\uff0c(\u5047\u8bbe\u8868\u540d\u4e3a stu\uff09<\/p>\n\n\n\n
desc stu;<\/code><\/pre>\n\n\n\n
\u589e\u52a0\u4e00\u5217\uff0c\uff08\u8868\u540d\u4e3a stu\uff0c\u65b0\u589e\u5217\u4e3a gender\uff09<\/p>\n\n\n\n
alter table stu add gender varchar(10);<\/code><\/pre>\n\n\n\n
\u53ea\u4fee\u6539\u67d0\u4e2a\u5217\u7684\u6570\u636e\u7c7b\u578b\uff0c\uff08\u8868\u540d stu\uff0c\u5217\u540d gender\uff09<\/p>\n\n\n\n
alter table stu modify gender int(10);<\/code><\/pre>\n\n\n\n
\u4fee\u6539\u67d0\u4e2a\u5217\u7684\u540d\u79f0\uff0c\u4ee5\u53ca\u6570\u636e\u7c7b\u578b\uff08\u8868\u540d stu\uff0c\u5217\u540dgender\uff0c\u65b0\u5217\u540d sex)<\/p>\n\n\n\n
alter table stu change gender sex varchar(10);<\/code><\/pre>\n\n\n\n
\u5220\u9664\u67d0\u4e00\u5217\uff0c\uff08\u8868\u540d stu\uff0c\u5217\u540d sex\uff09<\/p>\n\n\n\n
alter table stu drop sex;<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
1.\u6570\u636e\u5e93\u7684\u589e\u5220\u6539\u67e5\uff0c\u4e0e\u4f7f\u7528 1.\u67e5\u770b\u6240\u6709\u6570\u636e\u5e93\uff1a 2.\u521b\u5efa\u6570\u636e\u5e93\uff1a\uff08\u5047\u8bbe\u6570\u636e\u5e93\u540d mytest ) \u5982\u9700\u6307\u5b9a… \u7ee7\u7eed\u9605\u8bfb DDL — \u64cd\u4f5c\u6570\u636e\u5e93\u548c\u8868<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[4],"tags":[],"_links":{"self":[{"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/posts\/39"}],"collection":[{"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/comments?post=39"}],"version-history":[{"count":1,"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/posts\/39\/revisions"}],"predecessor-version":[{"id":40,"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/posts\/39\/revisions\/40"}],"wp:attachment":[{"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/media?parent=39"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/categories?post=39"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/tags?post=39"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}