A memorandum for HRR
======================

Type Casts
-----------

### PostgreSQL
http://www.postgresql.org/docs/9.2/static/sql-expressions.html#SQL-SYNTAX-TYPE-CASTS

> A type cast specifies a conversion from one data type to another.
> PostgreSQL accepts two equivalent syntaxes for type casts:
> 
>     CAST ( <expression> AS <type> )
>     <expression>::<type>
> 
> The CAST syntax conforms to SQL; the syntax with :: is historical PostgreSQL usage.

### SQL Server 2012
http://msdn.microsoft.com/en-US/library/ms187928(v=sql.110).aspx

> Syntax for CAST:
> 
>     CAST ( <expression> AS <data_type> [ ( <length> ) ] )

### SQLite3
http://www.sqlite.org/syntaxdiagrams.html#expr

> expr: (excerption)
> 
>     CAST ( <expr> AS <type-name> )
> 
> type-name:
> 
>     <name> [ ...n ] [ ( <signed-number> ) | ( <signed-number> , <signed-number> ) ]