Struct PreparedStatement 

pub struct PreparedStatement<'a, V: SQLParam> {
    pub text_segments: Box<[CompactString]>,
    pub params: Box<[Param<'a, V>]>,
    pub sql: CompactString,
}

A statement rendered once, whose placeholders are bound each time it runs.

Create one with prepare_render; drivers wrap it in their own prepared statement types. The SQL is stored as text segments with one parameter between each pair: [text, param, text, param, text]. Parameters that already had a value when the statement was rendered keep it.

Examples

use drizzle_core::prepared::prepare_render;
use drizzle_core::{ParamBind, Placeholder, SQL, ToSQL};

let sql: SQL<'_, Value> = SQL::raw("SELECT * FROM users WHERE id =")
    .append(Placeholder::named("id").to_sql());
let prepared = prepare_render(&sql);
assert_eq!(prepared.sql(), "SELECT * FROM users WHERE id = :id");
assert_eq!(prepared.external_param_count(), 1);

let (text, values) = prepared.bind([ParamBind::new("id", Value(5))])?;
assert_eq!(text, "SELECT * FROM users WHERE id = :id");
assert_eq!(values.collect::<Vec<_>>(), [Value(5)]);

Fields

text_segments: Box<[CompactString]>

Rendered SQL text between the parameters; one more than params.

params: Box<[Param<'a, V>]>

The parameters, in order.

sql: CompactString

The full SQL text, with the dialect’s placeholders.

Implementations

impl<'a, V: SQLParam> PreparedStatement<'a, V>

pub fn external_param_count(&self) -> usize

Returns how many bindings bind expects.

Counts parameters without a value, with each placeholder name counted once, since one binding fills every use of a name.

pub fn bind<T: SQLParam + Into<V>>( &self, param_binds: impl IntoIterator<Item = ParamBind<'a, T>>, ) -> Result<(&str, impl Iterator<Item = V>)>

Binds values to the placeholders and returns the SQL text with the values to send, in order.

Named bindings match placeholders by name; unnamed ones (ParamBind::positional) fill unnamed placeholders in order. For SQLite, a name used more than once is sent once.

Errors

Returns DrizzleError::ParameterError when a name is bound twice, a placeholder has no binding, or a binding matches no placeholder.

pub fn sql(&self) -> &str

Returns the SQL text, with the dialect’s placeholders.

Trait Implementations

impl<'a, V: Clone + SQLParam> Clone for PreparedStatement<'a, V>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a, V: Debug + SQLParam> Debug for PreparedStatement<'a, V>

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

Formats the value using the given formatter.

impl<V: SQLParam> Display for PreparedStatement<'_, V>

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

Formats the value using the given formatter.

impl<V: SQLParam> From<OwnedPreparedStatement<V>> for PreparedStatement<'_, V>

fn from(value: OwnedPreparedStatement<V>) -> Self

Converts to this type from the input type.

impl<'a, V: SQLParam> From<PreparedStatement<'a, V>> for OwnedPreparedStatement<V>

fn from(prepared: PreparedStatement<'a, V>) -> Self

Converts to this type from the input type.

impl<'a, V: SQLParam> ToSQL<'a, V> for PreparedStatement<'a, V>

fn to_sql(&self) -> SQL<'a, V>

Renders self as a SQL fragment.

fn into_sql(self) -> SQL<'a, V>

where Self: Sized,

Renders self as a SQL fragment, consuming it.