greptimedb/tests/cases/standalone/common/function/string/reverse.result

-- String REVERSE function tests
-- Basic REVERSE function
SELECT REVERSE('hello');

+------------------------+
| reverse(Utf8("hello")) |
+------------------------+
| olleh                  |
+------------------------+

SELECT REVERSE('world');

+------------------------+
| reverse(Utf8("world")) |
+------------------------+
| dlrow                  |
+------------------------+

SELECT REVERSE('');

+-------------------+
| reverse(Utf8("")) |
+-------------------+
|                   |
+-------------------+

SELECT REVERSE(NULL);

+---------------+
| reverse(NULL) |
+---------------+
|               |
+---------------+

-- REVERSE with numbers and special characters
SELECT REVERSE('12345');

+------------------------+
| reverse(Utf8("12345")) |
+------------------------+
| 54321                  |
+------------------------+

SELECT REVERSE('hello!');

+-------------------------+
| reverse(Utf8("hello!")) |
+-------------------------+
| !olleh                  |
+-------------------------+

SELECT REVERSE('a!@#$%b');

+--------------------------+
| reverse(Utf8("a!@#$%b")) |
+--------------------------+
| b%$#@!a                  |
+--------------------------+

-- REVERSE with palindromes
SELECT REVERSE('radar');

+------------------------+
| reverse(Utf8("radar")) |
+------------------------+
| radar                  |
+------------------------+

SELECT REVERSE('madam');

+------------------------+
| reverse(Utf8("madam")) |
+------------------------+
| madam                  |
+------------------------+

SELECT REVERSE('racecar');

+--------------------------+
| reverse(Utf8("racecar")) |
+--------------------------+
| racecar                  |
+--------------------------+

-- Test with table data
CREATE TABLE reverse_test(s VARCHAR, ts TIMESTAMP TIME INDEX);

Affected Rows: 0

INSERT INTO reverse_test VALUES
    ('hello', 1000),
    ('world', 2000),
    ('12345', 3000),
    ('radar', 4000),
    ('', 5000),
    (NULL, 6000);

Affected Rows: 6

SELECT s, REVERSE(s) FROM reverse_test ORDER BY ts;

+-------+-------------------------+
| s     | reverse(reverse_test.s) |
+-------+-------------------------+
| hello | olleh                   |
| world | dlrow                   |
| 12345 | 54321                   |
| radar | radar                   |
|       |                         |
|       |                         |
+-------+-------------------------+

-- Unicode REVERSE
SELECT REVERSE('世界');

+-----------------------+
| reverse(Utf8("世界")) |
+-----------------------+
| 界世                  |
+-----------------------+

SELECT REVERSE('café');

+-----------------------+
| reverse(Utf8("café")) |
+-----------------------+
| éfac                  |
+-----------------------+

SELECT REVERSE('🚀🌟');

+-----------------------+
| reverse(Utf8("🚀🌟")) |
+-----------------------+
| 🌟🚀                  |
+-----------------------+

-- REVERSE with spaces
SELECT REVERSE('hello world');

+------------------------------+
| reverse(Utf8("hello world")) |
+------------------------------+
| dlrow olleh                  |
+------------------------------+

SELECT REVERSE('  spaces  ');

+-----------------------------+
| reverse(Utf8("  spaces  ")) |
+-----------------------------+
|   secaps                    |
+-----------------------------+

-- Combining REVERSE with other functions
SELECT UPPER(REVERSE('hello'));

+-------------------------------+
| upper(reverse(Utf8("hello"))) |
+-------------------------------+
| OLLEH                         |
+-------------------------------+

SELECT REVERSE(UPPER('hello'));

+-------------------------------+
| reverse(upper(Utf8("hello"))) |
+-------------------------------+
| OLLEH                         |
+-------------------------------+

SELECT LENGTH(REVERSE('hello world'));

+--------------------------------------+
| length(reverse(Utf8("hello world"))) |
+--------------------------------------+
| 11                                   |
+--------------------------------------+

-- Double REVERSE (should return original)
SELECT REVERSE(REVERSE('hello world'));

+---------------------------------------+
| reverse(reverse(Utf8("hello world"))) |
+---------------------------------------+
| hello world                           |
+---------------------------------------+

SELECT REVERSE(REVERSE('中文测试'));

+------------------------------------+
| reverse(reverse(Utf8("中文测试"))) |
+------------------------------------+
| 中文测试                           |
+------------------------------------+

DROP TABLE reverse_test;

Affected Rows: 0