|Constructs a record with two fields named 1 and 2. Field _1 contains int value 1 while field _2 contains float value 2.0.|
|Constructs a record with two fields named a and b. Field a contains int value 1 while field b contains float value 2.0.|
(a: 1, 2) where some fields named and others are not is not
It is possible to construct a record with repeated field names as in
1, a: 2, b: 3). However, requesting field
a will trigger an ambiguity
error since it is not known which a to retrieve. Field
b can be
Record types have an order of their fields that is maintained. However, similarly to SQL implementations, there is no possibility to access the fields of a record by ordinal position. (Otherwise queries could accidentally refer to the wrong column in case of schema/view changes.)
Records cannot be compared with equality operators
=, <>, etc.
However, records can be compared using IS DISTINCT FROM / IS NOT DISTINCT FROM as
described in Comparisons.
Records can be casted to other records with the same field names and whose field values can be casted to the requested type.
cast( (a: 1, b: 2) as record(a: float, b: string) ) // (a: 1.0, b: "2")
cast( (a: 1, b: 2) as record(a: float) ) // Error!
A collection of tuple-2 can be casted to a map. If the element corresponding to the key appears more than once in the collection, only one of the keys is kept without ensuring which one.
CAST([(1,"x"), (2, "y")] AS MAP(int, string)) // map(1: "x", 2: "y")