Struct ComputedColumn 

pub struct ComputedColumn {
    pub function: QualifiedIdentifier,
    pub data_type: String,
    pub description: Option<String>,
    pub row_argument: Option<String>,
    pub session_argument: Option<String>,
    pub takes_arguments: bool,
}

A function of the table’s row type, read as though it were a column.

Fields

function: QualifiedIdentifier

The function to call.

data_type: String

What it returns.

description: Option<String>

The comment on the function, which is the field’s description.

A column’s description comes from a comment on the column; a computed column has no column to comment on, so it comes from the function – which is where a schema author would write it and where Hasura reads it from.

row_argument: Option<String>

The name of the parameter that takes the table’s row.

Usually the first and usually the only one, but not always: Hasura records a table_argument because a function may take the row second, after the session. Where it is not first the call has to be written in named notation, which is why the name is kept rather than the position.

session_argument: Option<String>

The name of the parameter filled from the caller’s session, if any.

A function with one is not callable from the REST surface, which has no session document to give it, and is skipped there.

takes_arguments: bool

Whether the function takes anything besides the row.

The REST surface has nowhere to write an argument and no session to supply, so it reads only the fields that take neither: a field it could only ever call wrongly is worse than a field that is not there.

Trait Implementations

impl Clone for ComputedColumn

fn clone(&self) -> ComputedColumn

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ComputedColumn

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ComputedColumn

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for ComputedColumn

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.