Mysql Explain Query显示类型“ ALL”

Question

SELECT id FROM raod_busroute 
WHERE from_des LIKE '%adheriya khal%' AND to_des LIKE
'%abhayapuri%' GROUP BY from_des"

When I look at the result, I see it Reads the entire table—all rows and columns. I know this is bad, but I don't know how to fix this.

Thanks

Answer 1

Because you are doing a lookup with like with wildcards in the beginning of the string, mysql cannot use your indexes (if there are any). It needs to do a full table scan.