Trait StrColExt 

pub trait StrColExt<T> {
    // Required methods
    fn lower(&self) -> ColExpr<T>;
    fn upper(&self) -> ColExpr<T>;
    fn length(&self) -> ColExpr<T>;
    fn trim(&self) -> ColExpr<T>;
    fn coalesce<V: Into<Value>>(&self, default: V) -> ColExpr<T>;
    fn concat<V: Into<Value>>(&self, suffix: V) -> ColExpr<T>;
}

String-function helpers — lower(), upper(), length(), trim(), coalesce(), concat(). Implemented for both StrCol<T> and NullableStrCol<T> so the extension methods work whether the column is String or Option<String>.

Each returns a ColExpr; chain a comparison (.eq / .ne / .lt …) to produce a Predicate<T> for filter / exclude. All six render identically on SQLite and Postgres (TRIM, COALESCE are standard SQL; || is the standard concatenation operator both backends accept).

Required Methods

fn lower(&self) -> ColExpr<T>

LOWER(col) — case-insensitive comparison primitive.

fn upper(&self) -> ColExpr<T>

UPPER(col).

fn length(&self) -> ColExpr<T>

LENGTH(col) — character count of the stored value.

fn trim(&self) -> ColExpr<T>

TRIM(col) — strip leading/trailing whitespace before comparing, so name.trim().eq("ada") matches a stored " ada ".

fn coalesce<V: Into<Value>>(&self, default: V) -> ColExpr<T>

COALESCE(col, default) — substitute default when the column is NULL, so a nullable column compares as the fallback. Mostly paired with NullableStrCol.

fn concat<V: Into<Value>>(&self, suffix: V) -> ColExpr<T>

col || suffix — append suffix (the standard SQL concatenation operator, which both backends accept) before comparing.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl<T> StrColExt<T> for NullableStrCol<T>

impl<T> StrColExt<T> for StrCol<T>