Transactions

EdgeQL supports atomic transactions. The transaction API consists of several commands:

start transaction: Start a transaction, specifying the isolation level, access mode (read only vs read write), and deferrability.
declare savepoint: Establish a new savepoint within the current transaction. A savepoint is a intermediate point in a transaction flow that provides the ability to partially rollback a transaction.
release savepoint: Destroys a savepoint previously defined in the current transaction.
rollback to savepoint: Rollback to the named savepoint. All changes made after the savepoint are discarded. The savepoint remains valid and can be rolled back to again later, if needed.
rollback: Rollback the entire transaction. All updates made within the transaction are discarded.
commit: Commit the transaction. All changes made by the transaction become visible to others and will persist if a crash occurs.

Client libraries

There is rarely a reason to use these commands directly. All EdgeDB client libraries provide dedicated transaction APIs that handle transaction creation under the hood.

Examples below show a transaction that sends 10 cents from the account of a BankCustomer called 'Customer1' to BankCustomer called 'Customer2'. The equivalent EdgeDB schema and queries are:

module default {
  type BankCustomer {
    required name: str;
    required balance: int64;
  }
}
update BankCustomer
    filter .name = 'Customer1'
    set { bank_balance := .bank_balance -10 };
update BankCustomer
    filter .name = 'Customer2'
    set { bank_balance := .bank_balance +10 }

TypeScript/JS

Using an EdgeQL query string:

Copy

client.transaction(async tx => {
  await tx.execute(`update BankCustomer
    filter .name = 'Customer1'
    set { bank_balance := .bank_balance -10 }`);
  await tx.execute(`update BankCustomer
    filter .name = 'Customer2'
    set { bank_balance := .bank_balance +10 }`);
});

Using the querybuilder:

Copy

const query1 = e.update(e.BankCustomer, () => ({
  filter_single: { name: "Customer1" },
  set: {
    bank_balance: { "-=":  10 }
  },
}));
const query2 = e.update(e.BankCustomer, () => ({
  filter_single: { name: "Customer2" },
  set: {
    bank_balance: { "+=":  10 }
  },
}));

client.transaction(async (tx) => {
  await query1.run(tx);
  await query2.run(tx);
});

Full documentation at Client Libraries > TypeScript/JS;

Python

Copy

async for tx in client.transaction():
    async with tx:
        await tx.execute("""update BankCustomer
            filter .name = 'Customer1'
            set { bank_balance := .bank_balance -10 };""")
        await tx.execute("""update BankCustomer
            filter .name = 'Customer2'
            set { bank_balance := .bank_balance +10 };""")

Full documentation at Client Libraries > Python;

Golang

Copy

err = client.Tx(ctx, func(ctx context.Context, tx *edgedb.Tx) error {
        query1 := `update BankCustomer
                filter .name = 'Customer1'
                set { bank_balance := .bank_balance -10 };`
        if e := tx.Execute(ctx, query1); e != nil {
                return e
        }
        query2 := `update BankCustomer
                filter .name = 'Customer2'
                set { bank_balance := .bank_balance +10 };`
        if e := tx.Execute(ctx, query2); e != nil {
                return e
        }
        return nil
})
if err != nil {
        log.Fatal(err)
}

Full documentation at Client Libraries > Go.

Rust

Copy

let balance_change_query = "update BankCustomer
  filter .name = <str>$0
  set { bank_balance := .bank_balance + <int32>$1 }";

client
    .transaction(|mut conn| async move {
        conn.execute(balance_change_query, &("Customer1", -10))
            .await
            .expect("Execute should have worked");
        conn.execute(balance_change_query, &("Customer2", 10))
            .await
            .expect("Execute should have worked");
        Ok(())
    })
    .await
    .expect("Transaction should have worked");

Full documentation at Client Libraries > Rust.

Transactions​

Client libraries​

TypeScript/JS​

Python​

Golang​

Rust​

Transactions

Client libraries

TypeScript/JS

Python

Golang

Rust