Easy local data persistence layer, backed by SQLite.
- Schema auto-defined by your Rust
struct
s - Automatic schema migrations
- Super-simple basic CRUD operations
- Use complex SQL if that's your jam
- Validates all SQL (including user-supplied) at compile time
In active development, updated February 2021! Contributions are very much welcome!
[dependencies]
turbosql = "0.1"
use turbosql::{Turbosql, Blob, select, execute};
#[derive(Turbosql, Default)]
struct Person {
rowid: Option<i64>, // rowid member required & enforced at compile time
name: Option<String>,
age: Option<i64>,
image_jpg: Option<Blob>
}
// INSERT a row
let rowid = Person {
rowid: None,
name: Some("Joe".to_string()),
age: Some(42),
image_jpg: None
}.insert().unwrap();
// SELECT all rows
let people: Vec<Person> = select!(Vec<Person>).unwrap();
// SELECT multiple rows with a predicate
let people: Vec<Person> = select!(Vec<Person> "WHERE age > ?", 21).unwrap();
// SELECT a single row with a predicate
let person: Person = select!(Person "WHERE name = ?", "Joe").unwrap();
// UPDATE
execute!("UPDATE person SET age = ? WHERE name = ?", 18, "Joe").unwrap();
// DELETE
execute!("DELETE FROM person WHERE rowid = ?", 1).unwrap();
See integration_test.rs
for more usage examples!
Turbosql generates a SQLite schema and prepared queries for each struct:
use turbosql::{Turbosql, Blob};
#[derive(Turbosql, Default)]
struct Person {
rowid: Option<i64>, // rowid member required & enforced
name: Option<String>,
age: Option<i64>,
image_jpg: Option<Blob>
}
↓ auto-generates and validates the schema
CREATE TABLE person (
rowid INTEGER PRIMARY KEY,
name TEXT,
age INTEGER,
image_jpg BLOB,
)
INSERT INTO person (rowid, name, age, image_jpg) VALUES (?, ?, ?, ?)
SELECT rowid, name, age, image_jpg FROM person
Queries with SQL predicates are also assembled and validated at compile time. Note that SQL types vs Rust types for parameter bindings are not currently checked at compile time.
let people = select!(Vec<Person> "WHERE age > ?", 21);
↓
SELECT rowid, name, age, image_jpg FROM person WHERE age > ?
At compile time, the #[derive(Turbosql)]
macro runs and creates a migrations.toml
file in your project root that describes the database schema.
Each time you change a struct
declaration and the macro is re-run (e.g. by cargo
or rust-analyzer
), migration SQL statements are generated that update the database schema. These new statements are recorded in migrations.toml
, and are automatically embedded in your binary.
#[derive(turbosql::Turbosql, Default)]
struct Person {
rowid: Option<i64>,
name: Option<String>
}
↓ auto-generates migrations.toml
migrations_append_only = [
'CREATE TABLE person(rowid INTEGER PRIMARY KEY)',
'ALTER TABLE person ADD COLUMN name TEXT',
]
output_generated_schema_for_your_information_do_not_edit = '''
CREATE TABLE person (
rowid INTEGER PRIMARY KEY,
name TEXT
)
'''
When your schema changes, any new version of your binary will automatically migrate any older database file to the current schema by applying the appropriate migrations in sequence.
This migration process is a one-way ratchet: Old versions of the binary run on a database file with a newer schema will detect a schema mismatch and will be blocked from operating on the futuristically-schema'd database file.
Unused or reverted migrations that are created during development can be manually removed from migrations.toml
before being released, but any database files that have already applied these deleted migrations will error and must be rebuilt. Proceed with care. When in doubt, refrain from manually editing migrations.toml
, and everything should work fine.
- Just declare and freely append fields to your
struct
s. - Check out the
migrations.toml
file that is generated in your project root to see what's happening. - If you run into any weird compiler errors, try just re-compiling first; depending on the order the proc macros run, sometimes it just needs a little push to get in sync after a schema change.
- Schema migrations are one-way, append-only. (SQLite doesn't even support
ALTER TABLE DROP {column}
, so we're not even going there for now.) - On launch, versions of your binary built with a newer schema will automatically apply the appropriate migrations to an older database.
- If you're feeling adventurous, you can add your own schema migration entries to the bottom of the list. (For creating indexes, etc.)
- Questions? Ask on Discord (https://discord.gg/RX3rTWUzUD) or open a GitHub discussion! -> https://github.com/trevyn/turbosql/discussions/new
The SQLite database is created in the directory returned by directories_next
::ProjectDirs::data_dir()
+ your executable's filename stem, which resolves to something like:
Linux |
|
macOS |
|
Windows |
|
SQLite is an extremely reliable database engine, but it helps to understand how it interfaces with the filesystem. The main .sqlite
file contains the bulk of the database. During database writes, SQLite also creates .sqlite-wal
and .sqlite-shm
files. If the host process is terminated without flushing writes, you may end up with these three files when you expected to have a single file. This is always fine; on next launch, SQLite knows how to resolve any interrupted writes and make sense of the world. However, if the -wal
and/or -shm
files are present, they must be considered essential to database integrity. Deleting them may result in a corrupted database. See https://sqlite.org/tempfiles.html .
integration_test.rs
for examples of what works today and is tested in CI.
Returns one value cast to specified type, returns
| |
Use tuple types for multiple manually declared columns. | |
Types must be specified in column names to generate an anonymous struct. | |
Vec<_> |
Returns
Anonymous structs work, too. |
Option<_> |
Returns |
Column list and table name are optional if type is a
You can use other struct types as well; column names must match the struct.
Sometimes everything is optional; this example will retrieve all | |
Inititally, this implementation might just open a new SQLite connection, and use it for all child calls. |
Your choice, but you definitely do not want to capitalize any of the other letters in the name! ;)