Struct Function 

pub struct Function { /* private fields */ }

A SQLite function call, with the decorations SQLite’s grammar hangs off one.

From https://www.sqlite.org/syntax/aggregate-function-invocation.html and https://www.sqlite.org/syntax/window-function-invocation.html:

name ( [ DISTINCT ] expr [, ...] [ ORDER BY ordering-term [, ...] ] | * )
    [ FILTER ( WHERE expr ) ]
name ( expr [, ...] | * ) [ FILTER ( WHERE expr ) ]
    OVER ( window-defn | window-name )

That is the whole list, and it is shorter than PostgreSQL’s. SQLite has no WITHIN GROUP (ORDER BY …) — an ordered-set aggregate is not a thing it has — and no column-definition list on a table-valued function, so neither appears here. The aggregate ORDER BY inside the argument list needs SQLite 3.44 or later.

use keelson_sqlite::{f, quote, window};

// count(*) OVER (PARTITION BY "user_id")
let e = f("count", "*").over(window::partition_by(quote("user_id")));

Implementations

impl Function

pub fn new( name: impl Into<Cow<'static, str>>, args: impl IntoExprList, ) -> Function

A call to name with args.

pub fn distinct(self) -> Function

DISTINCT, for an aggregate that should see each distinct input once.

pub fn order_by(self, order: impl IntoExpr) -> Function

Add a sort key to the aggregate’s own ORDER BY, inside the argument list: group_concat("name" ORDER BY "id").

SQLite 3.44 and later.

pub fn filter(self, condition: impl IntoExpr) -> Function

Add a condition to FILTER (WHERE …). Several are AND-joined.

pub fn over(self, mods: impl Mod<Window>) -> Expr

Attach OVER (…), built from window and frame mods.

Ends the builder, because OVER is the last thing in the grammar. over(()) gives the legal OVER (), which means the whole partition.

To reference a window declared in the statement’s WINDOW clause use over_name, not over(window::based_on(..)) — the parenthesised form is the copying one.

pub fn over_name(self, name: impl Into<Cow<'static, str>>) -> Expr

Attach OVER "w" — a reference to a window in the statement’s WINDOW clause.

Unparenthesised, which is what makes it a reference rather than a copy.

pub fn as_(self, alias: impl Into<Cow<'static, str>>) -> Expr

f(…) AS "alias" — the result-column alias.

Ends the builder for the same reason Chain::as_ does: an alias is not an operand.

Trait Implementations

impl Clone for Function

fn clone(&self) -> Function

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Function

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

Formats the value using the given formatter.

impl Default for Function

fn default() -> Function

Returns the “default value” for a type.

impl Expression for Function

fn write_sql(&self, w: &mut SqlWriter<'_>)

Append this fragment to w.

impl HasOrderBy for Function

fn order_by_mut(&mut self) -> &mut OrderBy

The ORDER BY clause to modify.

impl IntoExpr for Function

fn into_expr(self) -> Expr

Perform the conversion.

impl IntoExprList for Function

fn into_expr_list(self) -> Vec<Expr>

Perform the conversion.