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This article introduces the relevant knowledge of "what is the collation of mysql". In the operation of actual cases, many people will encounter such a dilemma. Then let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

The collation of mysql roughly means character order. First of all, characters are of no size, so the >, =, and < operations of characters need to have a rule of character order. That's what collation does. You can set the character order of a table or a field alone. A character type that has multiple character orders, such as:

Here is the character order corresponding to UTF8.

Utf8_general_ci utf8 33 Yes Yes 1

Utf8_bin utf8 83 Yes 1

Utf8_unicode_ci utf8 192 Yes 8

Utf8_icelandic_ci utf8 193 Yes 8

Utf8_latvian_ci utf8 194 Yes 8

Utf8_romanian_ci utf8 195 Yes 8

Utf8_slovenian_ci utf8 196 Yes 8

Utf8_polish_ci utf8 197 Yes 8

Utf8_estonian_ci utf8 198 Yes 8

Utf8_spanish_ci utf8 199 Yes 8

Utf8_swedish_ci utf8 200 Yes 8

Utf8_turkish_ci utf8 201 Yes 8

Utf8_czech_ci utf8 202 Yes 8

Utf8_danish_ci utf8 203 Yes 8

Utf8_lithuanian_ci utf8 204 Yes 8

Utf8_slovak_ci utf8 205 Yes 8

Utf8_spanish3_ci utf8 206 Yes 8

Utf8_roman_ci utf8 207 Yes 8

Utf8_persian_ci utf8 208 Yes 8

Utf8_esperanto_ci utf8 209 Yes 8

Utf8_hungarian_ci utf8 210 Yes 8

Utf8_sinhala_ci utf8 211 Yes 8

Utf8_german2_ci utf8 212 Yes 8

Utf8_croatian_ci utf8 213 Yes 8

Utf8_unicode_520_ci utf8 214 Yes 8

Utf8_vietnamese_ci utf8 215 Yes 8

Utf8_general_mysql500_ci utf8 223 Yes 1

The character order of mysql follows the naming convention. Use _ ci (for case insensitivity), _ cs (for case sensitivity), and _ bin (for comparison with coded values). For example:

CREATE TABLE `issue_ message` (

`id`int (11) NOT NULL AUTO_INCREMENT

`content` varchar (255) NOT NULL

PRIMARY KEY (`id`)

) ENGINE=MyISAM DEFAULT CHARSET=utf8

The two sql below this table will show the same result.

Select * from issue_message where content = 'Yes'

Select * from issue_message where content = 'yes'

If changed to the following definition:

CREATE TABLE `issue_ message` (

`id`int (11) NOT NULL AUTO_INCREMENT

`content` varchar (255) NOT NULL COLLATE utf8_bin

PRIMARY KEY (`id`)

) ENGINE=MyISAM DEFAULT CHARSET=utf8

Then the results of the two sql will be different.

Therefore, if you are sensitive to character size, it is best to set the default utf8_general_ci in the database to utf8_bin.

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