Data Access Layer

Our data access layer has the following directory outline:

dal
└── Cargo.toml
   ├── migrations
   │   └── 20240523088625_initial-setup.sql
   └── src
       ├── connections
       │   ├── mod.rs
       │   └── sqlx_postgres.rs
       ├── lib.rs
       ├── migrations.rs
       └── users
           ├── descriptors.rs
           ├── mod.rs
           ├── schema.rs
           └── transactions
               ├── create.rs
               ├── get.rs
               └── mod.rs

To avoid bloat of the chapter, we will not cover every line of boilerplate code. First off, ensure that all the files are linked...