问题
I have a WordPress website on my local WAMP server. But when I upload its database to live server, I get error
#1273 – Unknown collation: ‘utf8mb4_unicode_520_ci’
Any help would be appreciated!
回答1:
You can solve this by finding
ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_520_ci;
in your .sql file, and swapping it with
ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_general_ci;
回答2:
I believe this error is caused because the local server and live server are running different versions of MySQL. To solve this:
- Open the sql file in your text editor
- Find and replace all
utf8mb4_unicode_520_ciwithutf8mb4_unicode_ci - Save and upload to a fresh mySql db
Hope that helps
回答3:
In my case it turns out my
new server was running MySQL 5.5,
old server was running MySQL 5.6.
So I got this error when trying to import the .sql file I'd exported from my old server.
MySQL 5.5 does not support utf8mb4_unicode_520_ci, but
MySQL 5.6 does.
Updating to MySQL 5.6 on the new server solved collation the error !
If you want to retain MySQL 5.5, you can:
- make a copy of your exported .sql file
- replace instances of utf8mb4unicode520_ci and utf8mb4_unicode_520_ci
...with utf8mb4_unicode_ci
- import your updated .sql file.
回答4:
Open the sql file in your text editor;
1. Search: utf8mb4_unicode_ci Replace: utf8_general_ci (Replace All)
2. Search: utf8mb4_unicode_520_ci Replace: utf8_general_ci (Replace All)
3. Search: utf8mb4 Replace: utf8 (Replace All)
Save and upload!
回答5:
just remove "520_"utf8mb4_unicode_520_ci → utf8mb4_unicode_ci
回答6:
easy replace
sed -i 's/utf8mb4_unicode_520_ci/utf8mb4_unicode_ci/g' your_sql_file.sql
回答7:
find and replace:
utf8mb4_unicode_520_ci
with
utf8_general_ci
in whole sql file
回答8:
Getting collation error #1273 - Unknown collation: 'utf8mb4_unicode_520_ci' is caused by the difference of the MySQL version from which you export and our MySQL server to which you import. Basically, the Wordpress library for newer version checks to see what version of SQL your site is running on. If it uses MySQL version 5.6 or more, it assumes the use of a new and improved Unicode Collation Algorithm (UCA) called “utf8mb4_unicode_520_ci”. This is great unless you end up moving your WordPress site from a newer 5.6 version of MySQL to an older, pre 5.6 version of MySQL.
To resolve this you will either have to edit your SQL export file and do a search and replace, changing all instances of ‘utf8mb4_unicode_520_ci’ to ‘utf8mb4_unicode_ci’. Or follow the steps below if you have a PHPMyAdmin:
- Click the Export tab for the database
- Click the Custom radio button.
- Go the section titled Format-specific options and change the drop-down for Database system or older MySQL server to maximize output compatibility with: from NONE to MYSQL40.
- Scroll to the bottom and click GO.
回答9:
I just opened the dump.sql file in Notepad++ and hit CTRL+H to find and replace the string "utf8mb4_0900_ai_ci" and replaced it with "utf8mb4_general_ci". Source link https://www.freakyjolly.com/resolved-when-i-faced-1273-unknown-collation-utf8mb4_0900_ai_ci-error/
回答10:
Late to the party, but in case this happens with a WORDPRESS installation :
#1273 - Unknown collation: 'utf8mb4_unicode_520_ci
In phpmyadmin, under export method > Format-specific options( custom export )
Set to : MYSQL40
If you will try to import now, you now might get another error message :
1064 - You have an error in your SQL syntax; .....
That is because The older TYPE option that was synonymous with ENGINE was removed in MySQL 5.5.
Open your .sql file , search and replace all instances
from TYPE= to ENGINE=
Now the import should go smoothly.
回答11:
In my case I substitute it with utf8_general_ci with sed like this:
sed -i 's/utf8_0900_ai_ci/utf8_general_ci/g' MY_DB.sql
sed -i 's/utf8mb4_unicode_520_ci/utf8_general_ci/g' MY_DB.sql
After that, I can import it without any issue.
来源：https://stackoverflow.com/questions/42385099/1273-unknown-collation-utf8mb4-unicode-520-ci