Updating Tables
Adding a Column
Deleting a Column
Deleting Tables
6
Renaming a Table
Adding a Primary Key
Adding a Foreign Key
2
Deleting a Foreign Key
Adding an Index
Adding a Unique Index
Deleting an Index
CREATE
UNIQUE
INDEX
idx_name_ccode_district
ON
city (Name, CountryCode, District)
A
unique
index, in addition to the advantages of a regular index, ensures the uniqueness of records in the table by the fields specified
in
the index.