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_null(ty: &Type, 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&lt;u8&gt; BYTEA
HashMap&lt;String, Option&lt;String&gt;&gt; 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_json 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&lt;UTC&gt; TIMESTAMP WITH TIME ZONE
chrono::DateTime&lt;Local&gt; TIMESTAMP WITH TIME ZONE
chrono::DateTime&lt;FixedOffset&gt; TIMESTAMP WITH TIME ZONE
chrono::NaiveDate DATE
chrono::NaiveTime TIME
eui48::MacAddress MACADDR
uuid::Uuid UUID
bit_vec::BitVec BIT, VARBIT
eui48::MacAddress MACADDR

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.

Arrays

FromSql is implemented for Vec<T> where T implements FromSql, and corresponds to one-dimensional Postgres arrays.

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_null(ty: &Type, ctx: &SessionInfo) -> Result<Self>

Creates a new value of this type from a NULL SQL value.

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

The default implementation returns Err(Error::Conversion(Box::new(WasNull)).

Implementors