Skip to content

纠正一个小的笔误 #630

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Feb 12, 2020
Merged

纠正一个小的笔误 #630

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
1ac55b8
纠正一个小的笔误
rocky-peng Feb 1, 2020
debbca3
纠正一个小的笔误2
rocky-peng Feb 2, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion docs/database/一千行MySQL命令.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -242,7 +242,7 @@ SET NAMES GBK; -- 相当于完成以上三个设置
utf8 最大为21844个字符，gbk 最大为32766个字符，latin1 最大为65532个字符
varchar 是变长的，需要利用存储空间保存 varchar 的长度，如果数据小于255个字节，则采用一个字节来保存长度，反之需要两个字节来保存。
varchar 的最大有效长度由最大行大小和使用的字符集确定。
最大有效长度是65532字节，因为在varchar存字符串时，第一个字节是空的，不存在任何数据，然后还需两个字节来存放字符串的长度，所以有效长度是64432-1-2=65532字节。
最大有效长度是65532字节，因为在varchar存字符串时，第一个字节是空的，不存在任何数据，然后还需两个字节来存放字符串的长度，所以有效长度是65535-1-2=65532字节。
例：若一个表定义为 CREATE TABLE tb(c1 int, c2 char(30), c3 varchar(N)) charset=utf8; 问N的最大值是多少？ 答：(65535-1-2-4-30*3)/3
-- b. blob, text ----------
blob 二进制字符串（字节字符串）
Expand Down