列类型

类型映射

列类型将根据以下映射自动派生。

SQL Server (MSSQL) 后端

MSSQL 的类型映射可在此处找到。

Rust 基本数据类型的映射：

Rust type	Database Type (ColumnType)	SQLite datatype	MySQL datatype	PostgreSQL datatype
String	Char	char	char	char
String	String	varchar	varchar	varchar
i8	TinyInteger	tinyint	tinyint	char
u8	TinyUnsigned	tinyint	tinyint unsigned	N/A
i16	SmallInteger	smallint	smallint	smallint
u16	SmallUnsigned	smallint	smallint unsigned	N/A
i32	Integer	integer	int	integer
u32	Unsigned	integer	int unsigned	N/A
i64	BigInteger	integer	bigint	bigint
u64	BigUnsigned	integer	bigint unsigned	N/A
f32	Float	float	float	real
f64	Double	double	double	double precision
bool	Boolean	boolean	bool	bool
Vec<u8>	Binary	blob	blob	bytea

Rust 非基本数据类型的映射。你可以查看 entity/prelude.rs 了解所有重新导出的类型。

Rust type	Database Type (ColumnType)	SQLite datatype	MySQL datatype	PostgreSQL datatype
Date: chrono::NaiveDate TimeDate: time::Date	Date	date_text	date	date
Time: chrono::NaiveTime TimeTime: time::Time	Time	time_text	time	time
DateTime: chrono::NaiveDateTime TimeDateTime: time::PrimitiveDateTime	DateTime	datetime_text	datetime	timestamp
DateTimeLocal: chrono::DateTime<Local> DateTimeUtc: chrono::DateTime<Utc>	Timestamp	timestamp_text	timestamp	N/A
DateTimeWithTimeZone: chrono::DateTime<FixedOffset> TimeDateTimeWithTimeZone: time::OffsetDateTime	TimestampWithTimeZone	timestamp_with_timezone_text	timestamp	timestamp with time zone
Uuid: uuid::Uuid, uuid::fmt::Braced, uuid::fmt::Hyphenated, uuid::fmt::Simple, uuid::fmt::Urn	Uuid	uuid_text	binary(16)	uuid
Json: serde_json::Value	Json	json_text	json	json
Decimal: rust_decimal::Decimal	Decimal	real	decimal	decimal
PgVector: pgvector::Vector	Vector	N/A	N/A	vector
IpNetwork: ipnetwork::IpNetwork	Inet	N/A	N/A	inet

你可以使用 column_type 属性覆盖 Rust 类型与 ColumnType 之间的默认映射。

#[sea_orm(column_type = "Text")]
pub name: String
#[sea_orm(column_type = "Decimal(Some((16, 4)))")]
pub price: Decimal,

JSON 列

如果你需要将 JSON 字段反序列化为结构体，需要为其派生 FromJsonQueryResult。

#[derive(Clone, Debug, PartialEq, Eq, DeriveEntityModel)]
#[sea_orm(table_name = "json_struct")]
pub struct Model {
    #[sea_orm(primary_key)]
    pub id: i32,
    // JSON column as `serde_json::Value`
    pub json: Json,
    // JSON column as custom struct
    pub json_value: KeyValue,
    // nullable JSON column as custom struct, backed by jsonb (Postgres only)
    #[sea_orm(column_type = "JsonBinary")]
    pub json_value_opt: Option<KeyValue>,
    // JSON column storing a vector of objects
    pub json_value_vec: Vec<KeyValue>,
}

// The custom struct must derive `FromJsonQueryResult`, `Serialize` and `Deserialize`
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, FromJsonQueryResult)]
pub struct KeyValue {
    pub id: i32,
    pub name: String,
    pub price: f32,
    pub notes: Option<String>,
}

如果你想要一种跨数据库实现数组列的方式，可以使用封装类型包装它。

#[derive(Clone, Debug, PartialEq, Eq, DeriveEntityModel)]
#[sea_orm(table_name = "json_string_vec")]
pub struct Model {
    #[sea_orm(primary_key)]
    pub id: i32,
    // nullable JSON column storing a vector of string
    pub str_vec: Option<StringVec>,
}

#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, FromJsonQueryResult)]
pub struct StringVec(pub Vec<String>);

更多细节和示例请参阅下一章。

Postgres 数组

数组数据类型是 Postgres 专有功能。你可以定义 SeaORM 已支持的原始类型的向量。

#[derive(Clone, Debug, PartialEq, DeriveEntityModel)]
#[sea_orm(table_name = "collection")]
pub struct Model {
    #[sea_orm(primary_key)]
    pub id: i32,
    pub integers: Vec<i32>,
    pub integers_opt: Option<Vec<i32>>,
    pub floats: Vec<f32>,
    pub doubles: Vec<f64>,
    pub strings: Vec<String>,
}

Postgres Vector

自 1.1.6 起，添加了 PgVector 支持。需要 postgres-vector feature 标志。

#[derive(Clone, Debug, PartialEq, DeriveEntityModel)]
#[sea_orm(table_name = "image_model")]
pub struct Model {
    #[sea_orm(primary_key, auto_increment = false)]
    pub id: i32,
    pub embedding: PgVector,
}

完整示例请参阅 embedding_tests。

IpNetwork (Postgres)

自 1.1.8 起，添加了 IpNetwork 支持。需要 with-ipnetwork feature 标志。

#[derive(Clone, Debug, PartialEq, DeriveEntityModel)]
#[sea_orm(table_name = "host_network")]
pub struct Model {
    #[sea_orm(primary_key)]
    pub id: i32,
    pub ipaddress: IpNetwork,
    #[sea_orm(column_type = "Cidr")]
    pub network: IpNetwork,
}

Unix 时间戳

自 2.0.0 起，添加了多个新的封装类型，用于将 chrono / time 的 datetime 映射为 BigInteger。这些值在发送到数据库之前会转换为 i64。

#[derive(Clone, Debug, PartialEq, Eq, DeriveEntityModel)]
#[sea_orm(table_name = "access_log")]
pub struct Model {
    #[sea_orm(primary_key)]
    pub id: i32,
    pub ts: ChronoUnixTimestamp,
    pub ms: ChronoUnixTimestampMillis,
    pub ts: TimeUnixTimestamp,
    pub ms: TimeUnixTimestampMillis,
}