Enum ScalarFunctionForm 

#[non_exhaustive]
pub enum ScalarFunctionForm {
    PostgreSql,
    DuckDb,
    TSql,
    ClickHouse,
    Snowflake,
    MySql,
    Databricks,
    GoogleSql,
    Redshift,
    Custom(&'static str),
    Unsupported(&'static str),
}

Which scalar-function grammar this engine speaks.

The default is ScalarFunctionForm::PostgreSql, which is what an unlisted dialect has always been handed. It is a guess and a dangerous one on a near neighbour: LANGUAGE SQL IMMUTABLE PARALLEL SAFE is a “syntax error at or near PARALLEL” on Redshift, an engine that descends from PostgreSQL and reports itself as one. State your form.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

PostgreSql

CREATE FUNCTION … RETURNS … LANGUAGE SQL IMMUTABLE PARALLEL SAFE AS $$…$$ — PostgreSQL, Citus and Razeri’s agnostic renderer.

DuckDb

DuckDB’s CREATE MACRO.

TSql

T-SQL’s scalar UDF.

ClickHouse

ClickHouse’s lambda CREATE FUNCTION … AS (x) -> ….

Snowflake

Snowflake’s UDF.

MySql

MySQL/MariaDB’s CREATE FUNCTION … DETERMINISTIC.

Databricks

Databricks SQL’s UDF.

GoogleSql

GoogleSQL’s CREATE FUNCTION — BigQuery’s.

Redshift

Redshift’s: the volatility is mandatory rather than optional, there is no PARALLEL SAFE, LANGUAGE follows the body rather than preceding it, and the body addresses its parameters as $1 and never by name.

Custom(&'static str)

This engine has scalar functions and spells them in a grammar Razeri does not carry. The string is the grammar’s own name.

Your dialect renders the whole CREATE, through SqlRenderer::render_scalar_function. Razeri substitutes no near neighbour and refuses nothing; a dialect that answers Custom without overriding that method has promised a rendering it does not provide, and the conformance kit reports it.

Unsupported(&'static str)

This engine has no scalar function.

Rare — rare enough that no engine Razeri has measured is one — and the default was a silent PostgreSql for want of anywhere to say it. The string is the orientation an author reads: say what this engine offers instead before saying what it lacks, and name the near form if there is one.

It is prose that lands inside a SQL comment, so it must never spell a complete statement.

Implementations

impl ScalarFunctionForm

pub const fn refusal(self) -> Option<&'static str>

The dialect’s own refusal wording, or None where this engine has a scalar function.

pub const fn custom_grammar(self) -> Option<&'static str>

The name of the grammar this dialect renders itself, or None where Razeri renders the function.

Trait Implementations

impl Clone for ScalarFunctionForm

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ScalarFunctionForm

impl Debug for ScalarFunctionForm

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

Formats the value using the given formatter.

impl Default for ScalarFunctionForm

fn default() -> Self

Returns the “default value” for a type.

impl Eq for ScalarFunctionForm

impl PartialEq for ScalarFunctionForm

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for ScalarFunctionForm