= (equality operator)
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Purpose: Test if two
jsonb values are equal.
input values: jsonb = jsonb return value: boolean
Notes: There is no
json overload. If you want to test that two
json values are equal, express the predicate thus:
lhs_json_value::text = rhs_json_value::text
do $body$ declare j1 constant jsonb := '["a","b","c"]'; j2 constant jsonb := ' [ "a","b","c" ]'; begin assert j1 = j2, 'unexpected'; end; $body$;
Notice that the text definitions of the to-be-compared JSON values may differ in whitespace. Because
jsonb holds a fully parsed representation of the value, whitespace (except within primitive JSON string values and key names) has no meaning.
If you need to test two
json values for equality, then you must
::text typecast each.
See the account of the
::text operator when the input is a
json value. The
json representation preserves semantically insignificant whitespace and repeats occurrences of the same keys in an object. This implies that the equality comparison of two
json values would in general be unpredictable and therefore meaningless. This is why the
= operator doesn't have a
json overload and is is another reason to prefer consistently to choose to use
do $body$ declare j1 constant json := '["a","b","c"]'; j2 constant json := '["a","b","c"]'; j3 constant json := '["a","b", "c"]'; begin assert (j1::text = j2::text) and not (j1::text = j3::text), 'unexpected'; end; $body$;