Using SQL databases in a typed language is a pain unless you have great libraries to support you. There's a lot of different libraries for TypeScript, but they all have flaws.
This is complete overview of SQL libraries for TypeScript. If I'm missing a library, please let me know.
In an ORM you declare the schema completely in the host language (TypeScript). The ORM then completely manages synchronization between your objects / classes and the corresponding database tables.
ORMs always have the same issues: If you have somewhat complex queries, you will get to the limit of the ORM and not be able to represent that query in it without escape hatching. You also lose direct control over how the queries are handled, and thus may get surprising performance issues when the ORM uses dumb SQL queries in the background.