MySQL BaseRule.g4 file contains reserve words in identifierUnambiguousKeywords

[Yash-cor]

Feature Request

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Is your feature request related to a problem?

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Describe the feature you would like.

Some Reserve Keywords of MySQL are kept in identifierUnambiguousKeywords in BaseRule.g4

For Example:
RANK is a reserve keyword stored in identifierUnambiguousKeywords.

This causes it to parse SQL queries correctly like - SELECT id as rank FROM employees;
whereas MySQL does not allow this query to parse without using ```.

[Yash-cor]

Hello @strongduanmu could you please assign it to me.

[strongduanmu]

Hi @Yash-cor, thank you for your feedback. Although the MySQL documentation describes this, there are some hidden features. For example select table.id , table.condition from table where table.type=? in #32283, condition is a reserved word, but it is legal in this SQL.

At present, we have not fully understood how many hidden scenarios MySQL has, so ShardingSphere SQL Parser maintains as loose rules as possible, that is, it allows the use of reserved words as identifiers, so that no errors will be reported during parsing. If MySQL does not support this writing method, a parsing exception will be thrown during SQL execution.

If you are interested in this question, I think you can read the parsing in the MySQL source code and maybe find some clear rules.

[Yash-cor]

Hi @Yash-cor, thank you for your feedback. Although the MySQL documentation describes this, there are some hidden features. For example select table.id , table.condition from table where table.type=? in #32283, condition is a reserved word, but it is legal in this SQL.

At present, we have not fully understood how many hidden scenarios MySQL has, so ShardingSphere SQL Parser maintains as loose rules as possible, that is, it allows the use of reserved words as identifiers, so that no errors will be reported during parsing. If MySQL does not support this writing method, a parsing exception will be thrown during SQL execution.

If you are interested in this question, I think you can read the parsing in the MySQL source code and maybe find some clear rules.

Ok I will give it a try then, thanks for the response