The SQL CHECK constraint is fully defined by the SQL-92 standard, and is consistently implemented by all DBMS vendors.

Standard SQL-92 views are constructed from SQL SELECT statements that do not contain the GROUP BY clause.

SQL has a JOIN ON syntax that can be used to create inner joins and outer joins.

The SQL MAKE TABLE command is used to construct tables, define columns, define column constraints and create relationships.

The SQL statement used to create a view is CREATE VIEW.