*: better error message for ADMIN CHECK/RECOVER/CLEANUP INDEX

[bb7133]

Enhancement

When a table is defined with clustered index, the 'primary key' does not exist actually(primary key = record), so for syntax like ADMIN CHECK INDEX xxx primary``, a better error message would be better:

Current:

tidb> create table t(a int key clustered);
tidb> admin recover index t `primary`;
ERROR 1105 (HY000): index `primary` is not found in table `t`

Not every user knows the definition of "clustered index", we could report another message like:

ERROR 1105 (HY000): index `primary` is not defined in table `t` when the clustered index is defined.

[azhsmesos]

please assigned it to me, i want to try it

[CbcWestwolf]

/assign azhsmesos

[75asu]

hi @bb7133 , as there is no response from @azhsmesos , I would like to take this one
could you please assign me this one and help me with the file where this change needs to be done, I checked a lot but found so many results, need some help here

[azhsmesos]

sorry，please assigned to @measutosh ，I've been really busy these days and I'm sorry