learn sql codecademy

1. Sorting DataIf you do not sort, the data will generally appear in the order in which it appears in the underlying table, which may be the order in which the data was originally added to the table. However, if the data is subsequently updated or deleted, the order is affected by how the DBMS reuses the storage space.Clauses: SQL statements consist of clauses, some are necessary, and others are optional. A clause is usually made up of keywords plus t

)3.4FOREIGN key (foreign key)------used to mark a row of this table in another table or this table3.5CHECK------Ensure that a column of data meets a particular condition3.6The default------sets an initial value that is set to this value when the data is not assigned3.7INDEX------used to quickly create and retrieve data from a database4. This is a constraint summary, I'll try these constraints later, (not full,unique,primary key has been tried in the blog that added the primary key)(attached) MyS