Notations used in SQL-syntax representation

• Red italics is used for syntactic elements to be substituted by the names of the elements or by the structure identified. For example, table_name should be substituted by a name of some table.
• Bold black is used for SQL keywords, for example, 'create table'.  Commas are used in SQL as separators. Parentheses also belong to SQL.
• Brackets indicate an optional part of statement [ optional part ]. Brackets do not belong to SQL.
• Braces enclose a list of choices. One of the choices must be taken.  The choices are separated by bars, for example,  

           { choice 1 | choice 2 | choice 3 }. 

           Braces and bars do not belong to SQL.

• Three dots '...' indicate that the preceding element may be repeated. A comma followed by three dots ',...' indicates that the preceding element may be repeated and the elements are separated with commas.
• Some statements end with a semicolon. A semicolon and an empty line are used to separate statements. The need for semicolon at the end an SQL-statement depends on the execution environment. Many SQL interpreters demand it.