Struct TemplateArg 

pub struct TemplateArg<'q, DB: Database, D> { /* private fields */ }

SQL template argument processor handling safe parameter encoding and placeholder generation

Generic Parameters

• 'q: Lifetime for database arguments
• DB: Database type implementing [sqlx::Database]
• D: Template data type

Implementations

impl<'q, DB: Database, D> TemplateArg<'q, DB, D>

pub fn new(d: &'q D) -> Self

Creates a new TemplateArg instance wrapping template data

Arguments

• d - Reference to template data with lifetime 'q

pub fn set_encode_placeholder_fn(&mut self, f: fn(usize, &mut String))

Sets custom placeholder formatting function

Arguments

• f - Function that takes parameter index and appends placeholder

pub fn e<ImplEncode>(&self, t: ImplEncode) -> String

where ImplEncode: Encode<'q, DB> + Type<DB> + 'q,

Encodes a single parameter and returns its placeholder

Arguments

• t - Value implementing [sqlx::Encode] and [sqlx::Type]

Returns

Placeholder string (e.g., $1 or ?)

Example

let placeholder = arg.e(user_id);

pub fn el<ImplEncode>( &self, args: impl IntoIterator<Item = ImplEncode>, ) -> String

where ImplEncode: Encode<'q, DB> + Type<DB> + 'q,

Encodes an iterable of parameters and returns parenthesized placeholders

Arguments

• args - Iterator of encodable values

Returns

Comma-separated placeholders wrapped in parentheses

Example

let placeholders = arg.el(&[1, 2, 3]);

pub fn et<ImplEncode>(&self, t: &ImplEncode) -> String

where ImplEncode: Encode<'q, DB> + Type<DB> + Clone + 'q,

Clone-and-encode variant for types requiring cloning

Arguments

• t - Reference to clonable encodable value

pub fn etl<'arg_b, ImplEncode>( &self, args: impl IntoIterator<Item = &'arg_b ImplEncode>, ) -> String

where ImplEncode: Encode<'q, DB> + Type<DB> + Clone + 'q, 'q: 'arg_b,

Clone-and-encode list variant

Arguments

• args - Iterator of references to clonable values

pub fn get_err(&self) -> Option<Error>

Takes any encoding error that occurred

pub fn get_arguments(&self) -> Option<DB::Arguments<'q>>

Takes ownership of the encoded arguments

Trait Implementations

impl<'q, DB: Database, D> Deref for TemplateArg<'q, DB, D>

type Target = &'q D

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.