Struct QueryBuilder 

pub struct QueryBuilder<'a, T> { /* private fields */ }

A fluent Query Builder for constructing SQL queries.

Handles SELECT, INSERT, filtering (WHERE), pagination (LIMIT/OFFSET), and ordering.

Implementations

impl<'a, T: Model + Send + Sync + Unpin> QueryBuilder<'a, T>

pub fn new( db: &'a Database, table_name: &'static str, columns_info: Vec<ColumnInfo>, columns: Vec<String>, ) -> Self

Creates a new QueryBuilder instance.

Usually called via db.model::<T>().

pub fn filter<V>(self, col: &'static str, op: &'static str, value: V) -> Self

where V: 'static + for<'q> Encode<'q, Any> + Type<Any> + Send + Sync + Clone,

Adds a WHERE clause to the query.

Arguments

• col - The column name.
• op - The operator (e.g., “=”, “>”, “LIKE”).
• value - The value to compare against.

Example

db.model::<User>().filter("age", ">", 18).scan().await?;

pub fn order(self, order: &str) -> Self

pub fn preload(self) -> Self

pub fn join(self) -> Self

pub fn pagination( self, max_value: usize, default: usize, page: usize, value: isize, ) -> Result<Self, Error>

pub fn select(self, columns: &str) -> Self

Selects specific columns to return.

By default, all columns (*) are selected.

pub fn offset(self, offset: usize) -> Self

Sets the query offset (pagination).

pub fn limit(self, limit: usize) -> Self

Sets the maximum number of records to return.

pub async fn insert(&self, model: &T) -> Result<&Self, Error>

Inserts a new record into the database based on the model instance.

Uses manual string parsing to bind values (temporary solution until fuller serialization support).

pub fn to_sql(&self) -> String

Returns the generated SQL string (for debugging purposes, without arguments).

pub async fn scan<R>(self) -> Result<Vec<R>, Error>

where R: for<'r> FromRow<'r, AnyRow> + Send + Unpin,

Executes the query and returns a list of results.

Example

let users: Vec<User> = db.model::<User>().scan().await?;

pub async fn first<R>(self) -> Result<R, Error>

where R: for<'r> FromRow<'r, AnyRow> + Send + Unpin,

Executes the query and returns only the first result.

Automatically adds LIMIT 1 and orders by Primary Key if available.

Example

let user: User = db.model::<User>().filter("id", "=", 1).first().await?;