Make searching issues by keyword case insensitive on DB

[zeripath]

Most DBs apart from SQLite will use a default Collation that is not case insensitive.
This means that SearchIssuesByKeyword becomes case sensitive for db indexing - in
contrast to the bleve and elastic indexers.

This PR simply uses UPPER(...) to do the LIKE - and although it may be more efficient
to change collations this would be a non-trivial task.

Fix #13663

Signed-off-by: Andrew Thornton [email protected]

[zeripath]

I've put in 1.14 but this could move if necessary.

[zeripath]

This may be breaking - as it does change things but I think the previous behaviour is unintended

[lunny]

Another method is to implement a custom builder.Cond, we can name it ILike

// ILike defines ilike condition
type ILike [2]string
 
 var _ builder.Cond = ILike{"", ""}

// WriteTo write SQL to Writer
func (like ILike) WriteTo(w Writer) error {
   if _, err := fmt.Fprintf(w, "%s iLIKE ?", like[0]); err != nil {
   return err
}
// FIXME: if use other regular express, this will be failed. but for compatible, keep this
if like[1][0] == '%' \|\| like[1][len(like[1])-1] == '%' {
  w.Append(like[1])
} else {
  w.Append("%" + like[1] + "%")
}
  return nil
}

[6543]

@lunny sounds like a feature request/pull to xorm and follow up pull ...

[zeripath]

ILIKE isn't present in sqlite, mysql or transact SQL.

Changing the collation for these columns is most likely to be the correct solution but a very fiddly one indeed.

[lunny]

@6543 The feature could added to xorm, but as an external Cond implementation, this will also work.

var likeFunc func(s, v string) builder.Cond
// if it's postgres {
    likeFunc = func(s, v string) builder.Cond {
        return ILike{s,v}
    }
} else {
    likeFunc = func(s, v string) builder.Cond {
        return builder.Like{s,v}
    }
}

Then replace all builder.Like{k,v} to likeFunc(k,v).