<div align="center">
<img src="docs/SeaQL logo dual.png" width="320"/>
<h1>SeaSchema</h1>
<p>
<strong>🌿 SQL schema definition and discovery</strong>
</p>
[](https://crates.io/crates/sea-schema)
[](https://docs.rs/sea-schema)
[](https://github.com/SeaQL/sea-schema/actions/workflows/rust.yml)
</div>
## About
SeaSchema is a library to help you manage database schema for MySQL, Postgres and SQLite. It provides 1) type definitions for representing database schema mapping each database closely and 2) utilities to discover them.
[](https://github.com/SeaQL/sea-schema/stargazers/)
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## Architecture
The crate is divided into different modules:
+ `def`: type definitions
+ `query`: for querying information_schema
+ `parser`: for parsing information_schema (parsing sqldump is WIP)
+ `writer`: for exporting `Schema` into SeaQuery and SQL
+ `discovery`: query, parse and construct a `Schema`
JSON de/serialize on type definitions can be enabled with `with-serde`.
## Schema Discovery
Take the MySQL [Sakila Sample Database](tests/sakila/mysql/sakila-schema.sql) as example, given the following table:
```SQL
CREATE TABLE film_actor (
actor_id SMALLINT UNSIGNED NOT NULL,
film_id SMALLINT UNSIGNED NOT NULL,
last_update TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (actor_id,film_id),
KEY idx_fk_film_id (`film_id`),
CONSTRAINT fk_film_actor_actor FOREIGN KEY (actor_id) REFERENCES actor (actor_id) ON DELETE RESTRICT ON UPDATE CASCADE,
CONSTRAINT fk_film_actor_film FOREIGN KEY (film_id) REFERENCES film (film_id) ON DELETE RESTRICT ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
```
The [discovered schema result](tests/discovery/mysql/schema.rs):
```rust
TableDef {
info: TableInfo {
name: "film_actor",
engine: InnoDb,
auto_increment: None,
char_set: Utf8Mb4,
collation: Utf8Mb40900AiCi,
comment: "",
},
columns: [
ColumnInfo {
name: "actor_id",
col_type: SmallInt(
NumericAttr {
maximum: None,
decimal: None,
unsigned: Some(
true,
),
zero_fill: None,
},
),
null: false,
key: Primary,
default: None,
extra: ColumnExtra {
auto_increment: false,
on_update_current_timestamp: false,
generated: false,
default_generated: false,
},
expression: None,
comment: "",
},
ColumnInfo {
name: "film_id",
col_type: SmallInt(
NumericAttr {
maximum: None,
decimal: None,
unsigned: Some(
true,
),
zero_fill: None,
},
),
null: false,
key: Primary,
default: None,
extra: ColumnExtra {
auto_increment: false,
on_update_current_timestamp: false,
generated: false,
default_generated: false,
},
expression: None,
comment: "",
},
ColumnInfo {
name: "last_update",
col_type: Timestamp(
TimeAttr {
fractional: None,
},
),
null: false,
key: NotKey,
default: Some(
ColumnDefault {
expr: "CURRENT_TIMESTAMP",
},
),
extra: ColumnExtra {
auto_increment: false,
on_update_current_timestamp: true,
generated: false,
default_generated: true,
},
expression: None,
comment: "",
},
],
indexes: [
IndexInfo {
unique: false,
name: "idx_fk_film_id",
parts: [
IndexPart {
column: "film_id",
order: Ascending,
sub_part: None,
},
],
nullable: false,
idx_type: BTree,
comment: "",
functional: false,
},
IndexInfo {
unique: true,
name: "PRIMARY",
parts: [
IndexPart {
column: "actor_id",
order: Ascending,
sub_part: None,
},
IndexPart {
column: "film_id",
order: Ascending,
sub_part: None,
},
],
nullable: false,
idx_type: BTree,
comment: "",
functional: false,
},
],
foreign_keys: [
ForeignKeyInfo {
name: "fk_film_actor_actor",
columns: [
"actor_id",
],
referenced_table: "actor",
referenced_columns: [
"actor_id",
],
on_update: Cascade,
on_delete: Restrict,
},
ForeignKeyInfo {
name: "fk_film_actor_film",
columns: [
"film_id",
],
referenced_table: "film",
referenced_columns: [
"film_id",
],
on_update: Cascade,
on_delete: Restrict,
},
],
}
```