MySQL 5.7.12 import cannot create a JSON value from a string with CHARACTER SET 'binary'

Question

I exported my database with JSON columns in it. After I migrated to a new server, my import crashed every time with an error like:

cannot create a JSO

Answer 1

I had this problem with a dump. i was able to fix it by changing the line in the dump file from:

/*!40101 SET NAMES binary*/;

to

/*!40101 SET NAMES utf8mb4*/;

Answer 2

This worked for me, (I had control of the export to the sql file as well). There're lots of caveats; e.g. I knew that the fields would never be bigger than 1000 and wouldn't contain any non-ascii chars. Please do comment and tell me all the whys this is so bad tho :)

Before export

alter table <table> modify <json_column> varchar(1000);

Then after import

alter table <table> modify <json_column> json;

Answer 3

For the ones like me arived here using Symfony 4 / Doctrine : For some reasons the same entity can be resolved in a longtext MySQL type storing JSON; or a json MySQL type storing json. Manually setting longtext MySQL type resolved the problem in my particular case.

Answer 4

I faced the same issue today. Below were the findings for my case,

I asked one of my friend to generate an SQL dump for me to import. He used sequel-pro to generate the dump (export database). When I did the import it threw an error

Cannot create a JSON value from a string with CHARACTER SET 'binary'

So, there was an issue with the generated dump, all the json fields were converted to some raw format i.e. instead of value being

"{'key1':'value1', 'key2':'value2'}"

it was,

X'nfdsklsdsklnfjkbvkjsdbvkjhdfsbvkjdsbnvljkdsbvkjhdfbvkjdfbvjkdfb'

So, when importing the dump i.e. running the insert statements mysql could not process the data as it was not of json type.

Here is a link to the bug reported
https://github.com/sequelpro/sequelpro/issues/2397

You need to uncheck the Output BLOB fields as hex option.

Answer 5

You can apply a regex to the SQL text which you exported which will convert your binary strings into an insertable format. This was my quick and dirty fix when I faced this issue

(X'[^,\)]*')
CONVERT($1 using utf8mb4)

Applying this regex means

INSERT INTO json_table (json_column) VALUES (X'7B22666F6F223A2022626172227D');

will now become

INSERT INTO json_table (json_column) VALUES (CONVERT(X'7B22666F6F223A2022626172227D' using utf8mb4));

Answer 6

vim version For Lorcan O'Neill's answer

vi xxxx.sql
:%s/\(X'[^,\)]*'\)/CONVERT(\1 using utf8mb4)/g