Table names have all lowercase letters and underscores between words, also all table names need to be plural, e.g. invoice_items, orders.

If the table name contains serveral words, only the last one should be plural:

applications
application_functions
application_function_roles

Field names will be lowercase, generally singular case, and words are separated by underscores, e.g. order_amount, first_name

The foreign key is named with the singular version of the target table name with _id appended to it, e.g. order_id in the items table where we have items linked to the orders table.

Tables used to join two tables in a many to many relationship is named using the table names they link, with the table names in alphabetical order, for example items_orders.

Indexes should follow the naming pattern of idx_{column name}. For example, an index for the column created_by on a table would have an indexed named idx_created_by.

ALTER TABLE `#__my_table` ADD INDEX `idx_created_by` (`created_by`);

For indexes that use multiple columns, list each column by order of cardinality.

ALTER TABLE `#__my_table` ADD INDEX `idx_category_referenceid` (`category`, `referenced`);

Unique Indexes

Unique indexes follow the same pattern as above but should start with uidx_.

ALTER TABLE `#__my_table` ADD UNIQUE `uidx_alias` (`alias`);

Fulltext Indexes

Fulltext indexes follow the same pattern as above but should start with ftidx_.

ALTER TABLE `#__my_table` ADD FULLTEXT `ftidx_content` (`content`);