-- Test: COMMENT ON TABLE add & remove
CREATE TABLE comment_table_test (
	pk INT,
	val DOUBLE,
	ts TIMESTAMP TIME INDEX,
	PRIMARY KEY(pk)
);

Affected Rows: 0

-- Add table comment
COMMENT ON TABLE comment_table_test IS 'table level description';

Affected Rows: 0

SHOW CREATE TABLE comment_table_test;

+--------------------+---------------------------------------------------+
| Table              | Create Table                                      |
+--------------------+---------------------------------------------------+
| comment_table_test | CREATE TABLE IF NOT EXISTS "comment_table_test" ( |
|                    |   "pk" INT NULL,                                  |
|                    |   "val" DOUBLE NULL,                              |
|                    |   "ts" TIMESTAMP(3) NOT NULL,                     |
|                    |   TIME INDEX ("ts"),                              |
|                    |   PRIMARY KEY ("pk")                              |
|                    | )                                                 |
|                    |                                                   |
|                    | ENGINE=mito                                       |
|                    | WITH(                                             |
|                    |   comment = 'table level description'             |
|                    | )                                                 |
+--------------------+---------------------------------------------------+

SELECT table_comment
FROM information_schema.tables
WHERE table_schema = 'public'
  AND table_name = 'comment_table_test';

+-------------------------+
| table_comment           |
+-------------------------+
| table level description |
+-------------------------+

-- Remove table comment
COMMENT ON TABLE comment_table_test IS NULL;

Affected Rows: 0

SHOW CREATE TABLE comment_table_test;

+--------------------+---------------------------------------------------+
| Table              | Create Table                                      |
+--------------------+---------------------------------------------------+
| comment_table_test | CREATE TABLE IF NOT EXISTS "comment_table_test" ( |
|                    |   "pk" INT NULL,                                  |
|                    |   "val" DOUBLE NULL,                              |
|                    |   "ts" TIMESTAMP(3) NOT NULL,                     |
|                    |   TIME INDEX ("ts"),                              |
|                    |   PRIMARY KEY ("pk")                              |
|                    | )                                                 |
|                    |                                                   |
|                    | ENGINE=mito                                       |
|                    |                                                   |
+--------------------+---------------------------------------------------+

SELECT table_comment
FROM information_schema.tables
WHERE table_schema = 'public'
  AND table_name = 'comment_table_test';

+---------------+
| table_comment |
+---------------+
|               |
+---------------+

DROP TABLE comment_table_test;

Affected Rows: 0

-- Test: COMMENT ON COLUMN add & remove
CREATE TABLE comment_column_test (
	pk INT,
	val DOUBLE,
	ts TIMESTAMP TIME INDEX,
	PRIMARY KEY(pk)
);

Affected Rows: 0

-- Add column comment
COMMENT ON COLUMN comment_column_test.val IS 'value column description';

Affected Rows: 0

SHOW CREATE TABLE comment_column_test;

+---------------------+---------------------------------------------------------+
| Table               | Create Table                                            |
+---------------------+---------------------------------------------------------+
| comment_column_test | CREATE TABLE IF NOT EXISTS "comment_column_test" (      |
|                     |   "pk" INT NULL,                                        |
|                     |   "val" DOUBLE NULL COMMENT 'value column description', |
|                     |   "ts" TIMESTAMP(3) NOT NULL,                           |
|                     |   TIME INDEX ("ts"),                                    |
|                     |   PRIMARY KEY ("pk")                                    |
|                     | )                                                       |
|                     |                                                         |
|                     | ENGINE=mito                                             |
|                     |                                                         |
+---------------------+---------------------------------------------------------+

SELECT column_comment
FROM information_schema.columns
WHERE table_schema = 'public'
  AND table_name = 'comment_column_test'
  AND column_name = 'val';

+--------------------------+
| column_comment           |
+--------------------------+
| value column description |
+--------------------------+

-- Remove column comment
COMMENT ON COLUMN comment_column_test.val IS NULL;

Affected Rows: 0

SHOW CREATE TABLE comment_column_test;

+---------------------+----------------------------------------------------+
| Table               | Create Table                                       |
+---------------------+----------------------------------------------------+
| comment_column_test | CREATE TABLE IF NOT EXISTS "comment_column_test" ( |
|                     |   "pk" INT NULL,                                   |
|                     |   "val" DOUBLE NULL,                               |
|                     |   "ts" TIMESTAMP(3) NOT NULL,                      |
|                     |   TIME INDEX ("ts"),                               |
|                     |   PRIMARY KEY ("pk")                               |
|                     | )                                                  |
|                     |                                                    |
|                     | ENGINE=mito                                        |
|                     |                                                    |
+---------------------+----------------------------------------------------+

SELECT column_comment
FROM information_schema.columns
WHERE table_schema = 'public'
  AND table_name = 'comment_column_test'
  AND column_name = 'val';

+----------------+
| column_comment |
+----------------+
|                |
+----------------+

DROP TABLE comment_column_test;

Affected Rows: 0

-- Test: COMMENT ON FLOW add & remove
-- Prepare source & sink tables
CREATE TABLE flow_source_comment_test (
	desc_str STRING,
	ts TIMESTAMP TIME INDEX
);

Affected Rows: 0

CREATE TABLE flow_sink_comment_test (
	desc_str STRING,
	ts TIMESTAMP TIME INDEX
);

Affected Rows: 0

CREATE FLOW flow_comment_test
SINK TO flow_sink_comment_test
AS
SELECT desc_str, ts FROM flow_source_comment_test;

Affected Rows: 0

-- Add flow comment
COMMENT ON FLOW flow_comment_test IS 'flow level description';

Affected Rows: 0

SHOW CREATE FLOW flow_comment_test;

+-------------------+------------------------------------------------------+
| Flow              | Create Flow                                          |
+-------------------+------------------------------------------------------+
| flow_comment_test | CREATE FLOW IF NOT EXISTS flow_comment_test          |
|                   | SINK TO public.flow_sink_comment_test                |
|                   | COMMENT 'flow level description'                     |
|                   | AS SELECT desc_str, ts FROM flow_source_comment_test |
+-------------------+------------------------------------------------------+

SELECT comment
FROM information_schema.flows
WHERE flow_name = 'flow_comment_test';

+------------------------+
| comment                |
+------------------------+
| flow level description |
+------------------------+

-- Remove flow comment
COMMENT ON FLOW flow_comment_test IS NULL;

Affected Rows: 0

SHOW CREATE FLOW flow_comment_test;

+-------------------+------------------------------------------------------+
| Flow              | Create Flow                                          |
+-------------------+------------------------------------------------------+
| flow_comment_test | CREATE FLOW IF NOT EXISTS flow_comment_test          |
|                   | SINK TO public.flow_sink_comment_test                |
|                   | AS SELECT desc_str, ts FROM flow_source_comment_test |
+-------------------+------------------------------------------------------+

SELECT comment
FROM information_schema.flows
WHERE flow_name = 'flow_comment_test';

+---------+
| comment |
+---------+
|         |
+---------+

DROP FLOW flow_comment_test;

Affected Rows: 0

DROP TABLE flow_source_comment_test;

Affected Rows: 0

DROP TABLE flow_sink_comment_test;

Affected Rows: 0