Modern personal database solution for Windows

I currently use Simplenote to handle basic "databases" of a few hundred rows.

I’m looking to move away from Simplenote for these because:

• This data is long-term and obstructs access to what I like to use Simplenote for: short-term, disposable notes
• I’d like to be able to easily search within a "database" only, instead of across Simplenote
• Simplenote doesn’t allow relational (i.e. tabular) data outside of Markdown tables, which are too simple and require switching back and forth between Preview mode

However, most traditional DBMS solutions I’ve come across are not suitable because they lack a key feature that Simplenote has: they don’t have mobile equivalents that make the data easily browsable and updatable from my phone while always keeping my data in sync (in other words, they aren’t designed for personal users in the modern world).

Is there a personal database solution that solves my above problems while having a usable, syncable mobile app?