Attribute Macro inline_sql::inline_sql

#[inline_sql]

Mark a function that executes an SQL query.

The function body must follow the form query! { ... } or query!(...).

The return type of the function determines the behavior of the function. There are a few options for the return type:

• Result<(), E>: Execute the query without returning anything. Errors are still reported.
• Result<u64, E>: Execute the query and return the number of affected rows.
• Result<Vec<T>, E>: Execute the query and return the rows as a vector.
• Result<Option<T>, E>: Execute the query and return a single optional row.
• Result<RowStream, E>: Execute the query and return a RowStream.

The row type T must implement TryFrom<tokio_postgres::Row>. The TryFrom::Error type must implement Into<E>.

The error type E must implement From<tokio_postgres::Error>`.

For functions that return a Result<Option<T>, E>, an error is reported if the query returned more than one row.

You can generally not use a type alias in the return type of the function. The proc macro can not resolve the alias, and will not know which variant to generate.

Example 1: Ignore the query output.

use inline_sql::inline_sql;

#[inline_sql]
async fn create_pets_table(
  client: &tokio_postgres::Client
) -> Result<(), tokio_postgres::Error> {
  query! {
    CREATE TABLE pets (
      name TEXT PRIMARY KEY,
      species TEXT NOT NULL
    )
  }
}

Example: Return a Vec of rows.

use inline_sql::inline_sql;


#[inline_sql]
async fn get_pets_by_species(
  client: &tokio_postgres::Client,
  species: &str,
) -> Result<Vec<Pet>, tokio_postgres::Error> {
    query!(SELECT * FROM pets WHERE species = #species)
}

Example: Return an Option.

use inline_sql::inline_sql;


#[inline_sql]
async fn get_pet_by_name(
  client: &tokio_postgres::Client,
  name: &str,
) -> Result<Option<Pet>, tokio_postgres::Error> {
    query!(SELECT * FROM pets WHERE name = #name)
}

Example: Return the number of affected rows.

use inline_sql::inline_sql;


#[inline_sql]
async fn rename_species(
  client: &tokio_postgres::Client,
  old_species: &str,
  new_species: &str,
) -> Result<u64, tokio_postgres::Error> {
    query!(UPDATE pets SET species = #new_species WHERE species = #old_species)
}