utf8mb4_unicode_ci 和 utf8mb4_unicode_nopad_ci 有什么区别？
What is the difference between utf8mb4_unicode_ci and utf8mb4_unicode_nopad_ci?
我为我的数据库选择了 utf8mb4 字符集。
utf8mb4_unicode_ci 和 utf8mb4_unicode_nopad_ci 归类有什么区别？
来自doc
A 'nopad' as part of the name indicates that the collation is of type NO PAD as opposed to PADSPACE ... NO PAD collations regard trailing spaces as normal characters.
在 PADSPACE
CHAR (as well as VARCHAR and TEXT) values are compared without regard for trailing spaces. This does not apply to the LIKE pattern-matching operator, which takes into account trailing spaces.
If a unique index consists of a column where trailing pad characters are stripped or ignored, inserts into that column where values differ only by the number of trailing pad characters will result in a duplicate-key error.
我为我的数据库选择了 utf8mb4 字符集。
utf8mb4_unicode_ci 和 utf8mb4_unicode_nopad_ci 归类有什么区别？
来自doc
A 'nopad' as part of the name indicates that the collation is of type NO PAD as opposed to PADSPACE ... NO PAD collations regard trailing spaces as normal characters.
在 PADSPACE
CHAR (as well as VARCHAR and TEXT) values are compared without regard for trailing spaces. This does not apply to the LIKE pattern-matching operator, which takes into account trailing spaces.
If a unique index consists of a column where trailing pad characters are stripped or ignored, inserts into that column where values differ only by the number of trailing pad characters will result in a duplicate-key error.