Parse queries into objects

[vitusortner]

Create SqlParser that returns a query object, which holds information about the query (SELECT, DELETE, etc.).
This is only required for queries annotated with @Query.

This is the first step in making returning the result of inserting, updating or deleting records possible.

[ghost]

The Query needs to return simple data. (int, String, double, bool)

[vitusortner]

Parsing SQL queries seems more tricky than expected. Unluckily I didn't find a package that could help with that.

[cw-dev]

You might be interested in https://github.com/AlecStrong/sqlite-psi

It’s the backend for https://github.com/square/sqldelight

[vitusortner]

@cw-dev thanks, I'll take a look at it!

[simolus3]

I've written https://pub.dev/packages/sqlparser, which is a pure-Dart sql parser and static analyzer. Originally, it was written for another project, but it might be helpful to this library as well. It can turn any sql query into an AST (so you know whether it is an insert/update/select/etc.), so you could just do

final engine = SqlEngine();
print(engine.parse('SELECT * FROM tbl').rootNode is SelectStatement) // true

If you know the table structure at build-time, you can also register available tables to the sql engine by adding them to SqlEngine.knownTables. Then, SqlEngine.analyze can be used to figure out what's returned by queries and it can resolve the type of variables in the query.

[vitusortner]

This looks awesome and seems to be the right fit for the library's needs. Thanks @simolus3!

[vladimirfx]

As now is any way to do partial updates? With UPDATE queries or like Room's 2.2 partial updates.

[dkaera]

Many thanks to @simolus3 for the SQL parser, it saved a lot of time to solve this issue.
PR #733