Arabic value not getting saved in multi-language in pages table

[Mirza]

Hi All,

I have a processwire setup for multi language which is english and arabic.

I have a template called hotel which has title field act as hotel name for both EN & AR language.

Since a week ago I was getting the error in 

 

Quote

SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '88-14191' for key 'name1056_parent_id'

Since we have key  in pages table which states as below

Quote

UNIQUE KEY `name1056_parent_id` (`name1056`,`parent_id`),

So the field name1056 should store the Arabic value of the title field.

But its not storing the arabic value, since we have CHARACTER SET ascii for the field `name1056` as below

Quote

  `name1056` varchar(128) CHARACTER SET ascii DEFAULT NULL,

Can anyone explain me 

* On what basis character set is defined?

* Is there any specific reason for setting the ASCII character set?

 

Thanks in advance for the help.