In slow_log table sql_text column is BLOB We enabled slow_log to debug slow queries. But In slow_log table  sql_text column is BLOB.. It used to work fine before on 5.6 but now shows blob on 5.7 

(Clarification)  When saving the slowlog to a TABLE, what happens to BLOBs and TEXT strings that cannot be safely stored in some standard column?  Apparently, TEXT values are stored into a BLOB.  In that case, how do I get back the TEXT in the desired CHARACTER SET?
In 5.7 ; column sql_text is changed to BLOB... Hence, you need to use 
select CONVERT(sql_text USING utf8  ) from mysql.slow_log ;