>>> printSQL $ true & cast int4
(TRUE :: int4)

A safe version of cast which just matches a value with its type.

>>> printSQL (1 & astype int)
((1 :: int4) :: int)

inferredtype will add a type annotation to an Expression which can be useful for fixing the storage type of a value.

>>> printSQL (inferredtype true)
(TRUE :: bool)

TypeExpressions are used in casts and createTable commands.

The composite type corresponding to a relation can be expressed by its alias. A relation is either a composite type, a table or a view. It subsumes typetable and typeview and partly overlaps typedef.

An enumerated type can be expressed by its alias. typeenum is subsumed by typedef.

The enum or composite type in a Typedef can be expressed by its alias.

The composite type corresponding to a Table definition can be expressed by its alias. It is subsumed by typerow

The composite type corresponding to a View definition can be expressed by its alias. It is subsumed by typerow.

logical Boolean (true/false)

signed two-byte integer

signed two-byte integer

signed four-byte integer

signed four-byte integer

signed four-byte integer

signed eight-byte integer

signed eight-byte integer

arbitrary precision numeric type

single precision floating-point number (4 bytes)

single precision floating-point number (4 bytes)

double precision floating-point number (8 bytes)

double precision floating-point number (8 bytes)

currency amount

variable-length character string

fixed-length character string

fixed-length character string

variable-length character string

variable-length character string

binary data ("byte array")

date and time (no time zone)

date and time, including time zone

date and time, including time zone

calendar date (year, month, day)

time of day (no time zone)

time of day, including time zone

time of day, including time zone

time span

universally unique identifier

IPv4 or IPv6 host address

textual JSON data

binary JSON data, decomposed

variable length array

fixed length array

>>> renderSQL (fixarray @'[2] json)
"json[2]"

text search query

text search document

Object identifiers (OIDs) are used internally by PostgreSQL as primary keys for various system tables.

Range of integer

Range of bigint

Range of numeric

Range of timestamp without time zone

Range of timestamp with time zone

Range of date

Anonymous composite record

ColumnTypeExpressions are used in createTable commands.

used in createTable commands as a column constraint to note that NULL may be present in a column

used in createTable commands as a column constraint to ensure NULL is not present in a column

used in createTable commands as a column constraint to give a default

not a true type, but merely a notational convenience for creating unique identifier columns with type PGint2

not a true type, but merely a notational convenience for creating unique identifier columns with type PGint2

not a true type, but merely a notational convenience for creating unique identifier columns with type PGint4

not a true type, but merely a notational convenience for creating unique identifier columns with type PGint4

not a true type, but merely a notational convenience for creating unique identifier columns with type PGint8

not a true type, but merely a notational convenience for creating unique identifier columns with type PGint8

pgtype is a demoted version of a PGType

Specify TypeExpression from a Haskell type.

>>> printSQL $ pgtypeFrom @String
text

>>> printSQL $ pgtypeFrom @Double
float8

Like PGTyped but also accounts for null.

Specify null TypeExpression from a Haskell type.

>>> printSQL $ nulltypeFrom @(Maybe String)
text

>>> printSQL $ nulltypeFrom @Double
float8

Like PGTyped but also accounts for null.

Specify ColumnTypeExpression from a Haskell type.

>>> printSQL $ columntypeFrom @(Maybe String)
text NULL

>>> printSQL $ columntypeFrom @Double
float8 NOT NULL

Lift PGTyped to a field