column-mapping: set schemaID/tableID to 0 if numeric suffix is missing

[kennytm]

What problem does this PR solve?

(TOOL-1134) Support mixing names with and without numeric suffix.

What is changed and how it works?

Added an optional separator argument to column mapping. The suffix is extracted as prefix + separator + suffix.

If the name equals to prefix (without the separator), we treat this to mean using a zero numeric suffix, i.e. if prefix == "money", separator == "_":

• money → 0
• money_ → error
• money_5 → 5
• money_6 → 6
• money_7 → 7
• money_money_money → error
• mon → error
• not_money → error

Check List

Tests

• Unit test

Code changes

Side effects

Related changes

• Need to update the documentation

[csuzhangxc]

@GregoryIan @ericsyh Have we decided to support this?

if so, money, money_ and mon are all mapped to 0, we need to underline it in the doc to avoid misuse.

[kennytm]

We could also agree on a list of acceptable separators so that money and money_ works but not mo.

[IANTHEREAL]

mainly ambiguity problem, I think we can choose one in two way

• define prefix and separator, like prefix is money and separator is _, it also means money, and money_ are mapped to 0
• only define prefix, like prefix is money, money is mapped to 0 and ``money_` is invalid

The reason for this is based on the fact that we should provide a definition that is as simple and nature as possible, not easy to make mistakes. how about you? @kennytm @csuzhangxc

[kennytm]

The second option seems better. I suggest the following changes:

1. We extend the arguments to 4 elements

   arguments: [123, 'schemaprefix', 'tableprefix', '_']

   If the last argument is missing, it defaults to ''

2. Schema name must be schemaprefix or schemaprefix + sep + schemaID

3. Table name must be tableprefix or tableprefix + sep + tableID

[IANTHEREAL]

it's fine, and we still allow 3 elements arguments which implies sep is ""

[kennytm]

/run-all-tests

[kennytm]

PTAL @csuzhangxc @GregoryIan @ericsyh

[IANTHEREAL]

Rest LGTM

[IANTHEREAL]

LGTM @csuzhangxc PTAL

[csuzhangxc]

LGTM. Could you help to update the docs-cn or docs?

[kennytm]

pingcap/docs#1166.