Clickhouse: Cannot parse CSV with space delmiter.

[akuzm]

$ echo "1 2" | clickhouse-local -S "a int, b int" --input-format="CSV" --format_csv_delimiter=' ' -q "select * from table"
Code: 27, e.displayText() = DB::Exception: Cannot parse input: expected   before: 2\n: (at row 1)

Row 1:
Column 0,   name: a, type: Int32, parsed text: "1"
ERROR: There is no delimiter ( ). "2" found instead.

 (version 19.13.1.1)

Also, the expected before could use some quoting.

[alexey-milovidov]

BTW, we cannot support any delimiter that may happen to be parsed as part of value.
For example . is not supported as a delimiter, because we cannot determine, what 1.2 is.

But this is another issue: we support padding by spaces and skip spaces around values unconditionally* (before parsing delimiter). Better to introduce a setting... and probably turn it off automatically when delimiter is space.

* - this contradicts RFC.

[tavplubix]

It can be done with CustomSeparated format:

$ echo "1 2" | clickhouse-local -S "a int, b int" --input-format=CustomSeparated --format_custom_escaping_rule=CSV --format_custom_field_delimiter=' ' -q "select * from table"
1   2

[akuzm]

We should add an error message about unsupported delimiters, and maybe mention CustomSeparated.
It's just so annoying when a simple thing breaks for unknown reasons with a cryptic message, and the user has no idea what's wrong and how it can be fixed.

[akuzm]

I'm not woking on this now, so I'll remove myself from the assignees list.