Trait postgres::types::FromSql [−] [src]

pub trait FromSql: Sized {
    fn from_sql<R: Read>(ty: &Type, raw: &mut R, ctx: &SessionInfo) -> Result<Self>;
    fn accepts(ty: &Type) -> bool;

    fn from_sql_nullable<R: Read>(ty: &Type, raw: Option<&mut R>, ctx: &SessionInfo) -> Result<Self> { ... }
}

A trait for types that can be created from a Postgres value.

Types

The following implementations are provided by this crate, along with the corresponding Postgres types:

Rust type	Postgres type(s)
bool	BOOL
i8	"char"
i16	SMALLINT, SMALLSERIAL
i32	INT, SERIAL
u32	OID
i64	BIGINT, BIGSERIAL
f32	REAL
f64	DOUBLE PRECISION
String	VARCHAR, CHAR(n), TEXT, CITEXT
Vec<u8>	BYTEA
HashMap<String, Option<String>>	HSTORE

In addition, some implementations are provided for types in third party crates. These are disabled by default; to opt into one of these implementations, activate the Cargo feature corresponding to the crate's name. For example, the serde feature enables the implementation for the serde::json::Value type.

Rust type	Postgres type(s)
serialize::json::Json	JSON, JSONB
serde::json::Value	JSON, JSONB
time::Timespec	TIMESTAMP, TIMESTAMP WITH TIME ZONE
chrono::NaiveDateTime	TIMESTAMP
chrono::DateTime<UTC>	TIMESTAMP WITH TIME ZONE
chrono::DateTime<Local>	TIMESTAMP WITH TIME ZONE
chrono::DateTime<FixedOffset>	TIMESTAMP WITH TIME ZONE
chrono::NaiveDate	DATE
chrono::NaiveTime	TIME
uuid::Uuid	UUID

Nullability

In addition to the types listed above, FromSql is implemented for Option<T> where T implements FromSql. An Option<T> represents a nullable Postgres value.

Required Methods

`fn from_sql<R: Read>(ty: &Type, raw: &mut R, ctx: &SessionInfo) -> Result<Self>`

Creates a new value of this type from a Reader of the binary format of the specified Postgres Type.

The caller of this method is responsible for ensuring that this type is compatible with the Postgres Type.

`fn accepts(ty: &Type) -> bool`

Determines if a value of this type can be created from the specified Postgres Type.

Provided Methods

`fn from_sql_nullable<R: Read>(ty: &Type, raw: Option<&mut R>, ctx: &SessionInfo) -> Result<Self>`

Creates a new value of this type from a Reader of Postgres data.

If the value was NULL, the Reader will be None.