UPPER_ATTRIBUTE_NAMES function

Converts all applicable attribute names in a SUPER value to uppercase, using the same case conversion routine as the UPPER function. UPPER_ATTRIBUTE_NAMES supports UTF-8 multibyte characters, up to a maximum of four bytes per character.

To convert SUPER attribute names to lowercase, use the LOWER_ATTRIBUTE_NAMES function.

Syntax

UPPER_ATTRIBUTE_NAMES(super_expression)

Arguments

super_expression

A SUPER expression.

Return type

SUPER

Examples

Converting SUPER attribute names to uppercase

The following example uses UPPER_ATTRIBUTE_NAMES to convert the attribute names of all SUPER values in a table.

-- Create a table and insert several SUPER values.
CREATE TABLE t (i INT, s SUPER);

INSERT INTO t VALUES
  (1, NULL), 
  (2, 'a'::SUPER),
  (3, JSON_PARSE('{"AttributeName": "b"}')),
  (4, JSON_PARSE(
     '[{"Subobject": {"c": "c"},
        "Subarray": [{"d": "d"}, "e"]
      }]'));

-- Convert all attribute names to uppercase.
UPDATE t SET s = UPPER_ATTRIBUTE_NAMES(s);

SELECT i, s FROM t ORDER BY i;

 i |                        s
---+--------------------------------------------------
 1 | NULL
 2 | "a"
 3 | {"ATTRIBUTENAME":"B"}
 4 | [{"SUBOBJECT":{"C":"c"},"SUBARRAY":[{"D":"d"}, "e"]}]

Observe how UPPER_ATTRIBUTE_NAMES functions.

• NULL values and scalar SUPER values such as "a" are unchanged.

• In a SUPER object, all attribute names are changed to uppercase, but attribute values such as "b" remain unchanged.

• UPPER_ATTRIBUTE_NAMES applies recursively to any SUPER object that is nested inside a SUPER array or inside another object.

Using UPPER_ATTRIBUTE_NAMES on a SUPER object with duplicate attribute names

If a SUPER object contains attributes whose names differ only in their case, UPPER_ATTRIBUTE_NAMES will raise an error. Consider the following example.

SELECT UPPER_ATTRIBUTE_NAMES(JSON_PARSE('{"A": "A", "a": "a"}'));      

error:   Invalid input
code:    8001
context: SUPER value has duplicate attributes after case conversion.