Types

Every type a column can have, how each is written, and how each compares.

Type	Holds	Written	Shown as
bigint	a whole number of any size	1000000, 1_000_000, 1e18	digits
decimal	an exact number with a fractional part	1.05, 0.5e3	plain digits, no exponent
bool	true or false	true, false	true / false
string	text	'Transfer', "it's"	itself
bytes	any number of bytes	hex longer than 32 bytes, $data	lowercase 0x…
bytes1 … bytes32	exactly N bytes	0xff is bytes1, a 64-digit hex is bytes32	lowercase 0x…
address	a chain and 20 bytes	ethereum:0x…	chain:0xChecksummed
chain	a chain	no literal; $chain, chain(x)	its name, ethereum
datetime	an instant, to the second, UTC	datetime('2026-09-01')	2026-09-01T00:00:00Z
duration	a whole number of seconds	30s, 15m, 1h, 7d, 2w	3600s
T[]	an array of one type	[a, b], r.getStakingModuleIds()	its elements
record	named fields	{ a: 1, b: 2 }	its fields
null	no value	null	null

Comparing

== and != work between values of the same type. The ordering operators <, <=, > and >= work on numbers, datetimes, durations and bytes of the same width. Two exceptions are worth knowing:

• A bigint and a decimal compare as numbers; 1 == 1.0 is true.
• An address compares with a bare 20-byte literal by its bytes alone, ignoring the chain — t.to == 0x7f39c581f595b53c5cb19bd0b3f8da6c935e2ca0 matches on any chain. In a query that spans two chains CQL warns (CQL2901); write the address with its chain to say which you meant.

bytes4 == bytes32 is a type error, and so is comparing a string with a bigint.

Converting

From	To	Use
bytesN, string, decimal	bigint	tobigint(x)
bigint, string	decimal	todecimal(x)
bigint with a scale	decimal	format(x, decimals)
decimal with a scale	bigint	parse(d, decimals)
anything	string	tostring(x)
bigint, bytes, address	hex string	tohex(x)
a 32-byte word	address, uint8…uint256, int8…int256, bytes1…bytes32, bool, string	x as address
string or unix seconds	datetime	datetime(x)
datetime	unix seconds	unixtime(t)
seconds	duration	duration(n)

x as T reinterprets one 32-byte word — a storage slot or a bytes32 — the way Solidity lays it out: as address takes the low 20 bytes, as uint8 the low byte, as bytes4 the high four. Read a storage slot uses it.

Arithmetic across types

• datetime ± duration is a datetime; datetime - datetime is a duration.
• duration ± duration, duration * bigint and duration / bigint are durations.
• bigint ± decimal is a decimal. + does not join strings or bytes; use concat.

Null

Any column can be null: a call the contract reverted, a decode that did not fit, an event argument this interval's ABI lacks. null passes through every operator and function — null + 1 is null — except isnull, isnotnull, coalesce and iff, which exist to deal with it. In where, only true keeps a row; null drops it like false does.

See also

• Numbers — bigint and decimal in practice.
• Functions — every conversion above.