The "Unknown:"s below indicate that an entry is incomplete.

• either the entry exist in the language, and please tell.
• either the entry doesn't exist in the language, and please tell so. The entry will be marked as such and won't appear as missing anymore.

• Various

  --	commenting (until end of line)
  < > <= >=	comparison
  min / max	comparison (min / max (binary or more))
  = <>	equality / inequality (deep)
  ( ... )	grouping expressions
  case-insensitive	tokens (case-sensitivity (keywords, variable identifiers...))

• Control Flow

  CASE val WHEN v1 THEN ... WHEN v2 THEN ... ELSE ... END

  multiple selection (switch)

• Types

  CAST(e as t)

  cast (upcast)

• Strings

  SUBSTRING(s FROM n len)	extract a substring
  POSITION(needle IN s)	locate a substring
  ||	string concatenation
  CHARACTER_LENGTH	string size
  '...'	strings (with no interpolation of variables)
  CHAR, VARCHAR(size)	type name
  upper / lower	uppercase / lowercase / capitalized string

• Booleans

  FALSE	false value
  TRUE	true value

• Bags and Lists

  in	is an element in the list
  count	list size
  distinct	remove duplicates
  order by	sort

• Various Data Types

  COALESCE	optional value (null coalescing)
  NULL	optional value (null value)

• Mathematics

  + / - / * / /	addition / subtraction / multiplication / division
  1000., 1E3	numbers syntax (floating point)
  B'1', X'F'	numbers syntax (integers in base 2, octal and hexadecimal)
  1000	numbers syntax (integers)
  NUMERIC, DECIMAL, DOUBLE PRECISION	type name (floating point)
  INTEGER, INT, SMALLINT	type name (integers)