Fix `CREATE TABLE` example by moving a comment.

[AntonFriberg]

Here https://clickhouse.com/docs/en/sql-reference/statements/create/table#with-explicit-schema

It is listed as

CREATE TABLE [IF NOT EXISTS] [db.]table_name [ON CLUSTER cluster]
(
    name1 [type1] [NULL|NOT NULL] [DEFAULT|MATERIALIZED|EPHEMERAL|ALIAS expr1] [compression_codec] [TTL expr1] [COMMENT 'comment for column'],
    name2 [type2] [NULL|NOT NULL] [DEFAULT|MATERIALIZED|EPHEMERAL|ALIAS expr2] [compression_codec] [TTL expr2] [COMMENT 'comment for column'],
    ...
) ENGINE = engine
  COMMENT 'comment for table'

But if I try to create a table with a column with comment I get an error using the order above.

ClickHouse client version 23.10.1.1976 (official build).
Connecting to localhost:9000 as user admin.
Connected to ClickHouse server version 23.10.1 revision 54466.

625795cd2cec :) create table x( `test` Nullable(String) CODEC(ZSTD) COMMENT 'Some comment') Engine=Memory;

Syntax error: failed at position 53 ('COMMENT'):

create table x( `test` Nullable(String) CODEC(ZSTD) COMMENT 'Some comment') Engine=Memory;

Expected one of: TTL, PRIMARY KEY, token, Comma, ClosingRoundBracket

But if I change the order it works.

ClickHouse client version 23.10.1.1976 (official build).
Connecting to localhost:9000 as user admin.
Connected to ClickHouse server version 23.10.1 revision 54466.

625795cd2cec :) create table x( `test` Nullable(String) COMMENT 'Some comment' CODEC(ZSTD)) Engine=Memory;

CREATE TABLE x
(
    `test` Nullable(String) COMMENT 'Some comment' CODEC(ZSTD)
)
ENGINE = Memory

Query id: 7aee263b-70a9-44e1-a1f9-dd70d512a994

Ok.

0 rows in set. Elapsed: 0.005 sec.

[johnnymatthews]

Are you trying to add a comment to the column, or the table? To add a table comment:

CREATE TABLE x
  (
    `test` Nullable(String) 
    CODEC(ZSTD)
  ) 
  Engine=Memory
  COMMENT 'Some comment';

To add a column comment:

CREATE TABLE x
 (
   `test` Nullable(String) 
   CODEC(ZSTD)
 ) 
 Engine=Memory;

ALTER TABLE x COMMENT COLUMN test 'This is a test column.';

In the interest of keeping this repo clean, I'm gonna close this issue as solved. But if you're still having issues, or I haven't actually addressed your problem, feel free to add further comments.

[AntonFriberg]

@johnnymatthews I want to add a comment to a column during table creation.

[AntonFriberg]

Which works but the order is different than in the documentation.

CREATE TABLE x
(
    `test` Nullable(String) COMMENT 'Some comment' CODEC(ZSTD)
)
ENGINE = Memory;

Note that codec is after comment.

[johnnymatthews]

Ah, I see! I'll make a PR.