Consult everybody:
I used is essentially, you can build clustered index, the column can be null, can also be repeated data (two rows of data is the same),
Use MYSQL found no clustered index, now has four kinds: FULLTEXT, SPATIAL, FULLTEXT, NORMAL.
Excuse me, how the MYSQL building clustered index?
I am using c #, can you write the SQL statement, and, what with the HASH or BTREE?