About
SeaSchema is a library to help you manage database schema for MySQL, Postgres and SQLite. It provides a suite of tools, including schema definition, discovery and migration.
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
migration
: schema manager and migrator
JSON de/serialize on type definitions can be enabled with with-serde
.
Schema Discovery
Take the MySQL Sakila Sample Database as example, given the following table:
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:
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,
},
],
}