SurrealDB - define field type - try to create entry with incorrect type (int, string)

• SCHEMAFULL

• TABLE

• FIELD

• DEFINE

• Using the DEFINE keyword we can define a table to have schema, then we can define the column and their type.

• Then if we try to insert (CREATE) an entry that does not match the type the query will fail. We need to use check to verify success.

use serde::{Deserialize, Serialize};
use surrealdb::engine::local::Mem;
use surrealdb::sql::Thing;
use surrealdb::Surreal;

#[derive(Debug, Deserialize, Serialize)]
struct Entry {
    id: Thing,
    number: u32,
}

#[tokio::main]
async fn main() -> surrealdb::Result<()> {
    let dbh = Surreal::new::<Mem>(()).await?;

    dbh.use_ns("demo").use_db("demo").await?;

    dbh.query("DEFINE TABLE entry SCHEMAFULL").await?;
    dbh.query("DEFINE FIELD number ON TABLE entry TYPE int")
        .await?;

    let res = dbh
        .query(
            "CREATE entry CONTENT {
        number: 42,
    };",
        )
        .await?;
    match res.check() {
        Ok(val) => println!("Success: {val:?}"),
        Err(err) => println!("Error: {err}"),
    }
    println!("---------");

    let res = dbh
        .query(
            "CREATE entry CONTENT {
        number: 'fortytwo',
    };",
        )
        .await?;
    match res.check() {
        Ok(val) => println!("Success: {val:?}"),
        Err(err) => println!("Error: {err}"),
    }

    println!("---------");
    let mut entries = dbh.query("SELECT * FROM entry").await?;
    let entries: Vec<Entry> = entries.take(0)?;
    for entry in entries {
        println!("{} {}", entry.id, entry.number);
    }
    println!("---------");

    Ok(())
}

Success: Response { client: Surreal { router: OnceLock(Router { sender: Sender { .. }, last_id: 4, features: {Backup, LiveQueries} }), engine: PhantomData<surrealdb::api::engine::any::Any> }, results: {0: (Stats { execution_time: Some(639.419µs) }, Ok(Array(Array([Object(Object({"id": Thing(Thing { tb: "entry", id: String("y93feg7h3xxu6ww51spz") }), "number": Number(Int(42))}))]))))}, live_queries: {} }
---------
Error: Found 'fortytwo' for field `number`, with record `entry:o31e2ou83s5buvxc55yq`, but expected a int
---------
entry:y93feg7h3xxu6ww51spz 42
---------