sqlparser breaks CURRENT_TIMESTAMP for sqlite

[lovasoa]

In SQLPage, we parse SQL queries using sqlparser in order to be able to modify them, and then dump them as text to run them on the database. This requires the process of parsing and then stringifying back not to break the semantics nor the syntax of the query.

However, the following SQLite query:

SELECT CURRENT_TIMESTAMP;

when parsed and then dumped back, gives:

SELECT CURRENT_TIMESTAMP();

This breaks the syntax for SQLite, which gives

sqlite> SELECT CURRENT_TIMESTAMP();
Error: in prepare, near "(": syntax error (1)

[alamb]

Thanks @lovasoa the "do we have trailing parens" is already tracked by the "special" flag:

https://github.com/sqlparser-rs/sqlparser-rs/blob/eb288487a6a938b45004deda850e550a74fcf935/src/ast/mod.rs#L3494-L3496

https://github.com/sqlparser-rs/sqlparser-rs/blob/eb288487a6a938b45004deda850e550a74fcf935/src/ast/mod.rs#L3522-L3523

Perhaps we just need to adjust the mysql dialect to set that too

[lovasoa]

@alamb : thanks for the pointers ! I opened a PR