Checking the text maximum length with CHECK

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WITH column_checks AS (SELECT
    ns.nspname AS table_schema,
    cls.relname AS table_name,
    a.attname AS column_name,
    COALESCE(basetype.typname, t.typname) AS data_type,
    pg_get_constraintdef(c.oid) AS check_clause,
	'TABLE CHECK' AS check_type
FROM
    pg_constraint c
INNER JOIN
    pg_class cls ON c.conrelid = cls.oid
INNER JOIN
    pg_namespace ns ON cls.relnamespace = ns.oid
INNER JOIN
    pg_attribute a ON a.attrelid = c.conrelid AND a.attnum = c.conkey[1]
INNER JOIN
    pg_type t ON a.atttypid = t.oid
LEFT JOIN
    pg_type basetype ON t.typtype = 'd' AND t.typbasetype = basetype.oid
WHERE
    c.contype = 'c'
    AND c.conrelid != 0
    AND cardinality(c.conkey) = 1

UNION ALL

SELECT
    ns.nspname AS table_schema,
    cls.relname AS table_name,
    a.attname AS column_name,
    basetype.typname AS data_type,
    pg_get_constraintdef(c.oid) AS check_clause,
	'DOMAIN CHECK' AS check_type
FROM
    pg_attribute a
INNER JOIN
    pg_class cls ON a.attrelid = cls.oid
INNER JOIN
    pg_namespace ns ON cls.relnamespace = ns.oid
INNER JOIN
    pg_type t ON a.atttypid = t.oid
INNER JOIN
    pg_constraint c ON c.contypid = t.oid
INNER JOIN
    pg_type basetype ON t.typbasetype = basetype.oid
WHERE
    cls.relkind IN ('r', 'p', 'f')
    AND a.attnum > 0
    AND NOT a.attisdropped
    AND t.typtype = 'd'
    AND c.contype = 'c')
SELECT table_schema, table_name, column_name, data_type, check_clause, check_type
FROM column_checks
WHERE check_clause~'(length.*<(=){0,1}.*(?<![_[:alpha:]])[[:digit:]]+|length.*(?<![_[:alpha:]])[[:digit:]]+.*>|\{,[[:digit:]]+\})'
AND data_type~*'(char|text)'
ORDER BY table_schema, table_name, column_name;