SQL and booleans, some trivia

Some trivia about SQL and booleans:

SQL 1992 defines three values for a boolean:

<truth value> ::=
        TRUE
      | FALSE
      | UNKNOWN

True booleans aren’t always supported, though. Here’s the truth table of boolean support:

SQL Dialect	Supports booleans
DB2	0 (use 1/0 instead)
Derby	true (you can safely use true/false)
H2	true
HSQLDB	true
Ingres	true
MySQL	true
Oracle	0
Postgres	true
SQL Server	0
SQLite	0
Sybase ASE	0
Sybase SQL Anywhere	0

Trivia… but nice to know.