glite/tx

Statements inside a transaction.

A transaction’s callback runs in the calling process, holding the connection, and gets a Tx. Nothing else uses the connection until the callback returns, so no other caller’s statements can mix into the transaction. Use only the Tx inside the callback: calling the Connection from there panics, because the callback holds it.

Once the call’s call_timeout_ms has passed, every statement on the Tx returns Timeout without running, so a body that keeps going after a timeout can’t keep the connection busy with more SQL.

Types

Tx

opaque </>

A running transaction.

pub opaque type Tx

Values

exec

</>

pub fn exec(
  tx: Tx,
  sql: String,
  params: List(value.Value),
) -> Result(Int, error.Error)

Run one statement and return the number of rows it changed.

exec_many

</>

pub fn exec_many(
  tx: Tx,
  sql: String,
  params: List(List(value.Value)),
) -> Result(Int, error.Error)

Run one statement once per parameter list, all or nothing.

exec_script

</>

pub fn exec_script(
  tx: Tx,
  sql: String,
) -> Result(Nil, error.Error)

Run a script of several statements, without parameters.

query

</>

pub fn query(
  tx: Tx,
  sql: String,
  params: List(value.Value),
  decoder: decode.RowDecoder(a),
) -> Result(List(a), error.Error)

Run a query and decode every row.

query_one

</>

pub fn query_one(
  tx: Tx,
  sql: String,
  params: List(value.Value),
  decoder: decode.RowDecoder(a),
) -> Result(a, error.Error)

Run a query that returns exactly one row, and decode it.

query_rows

</>

pub fn query_rows(
  tx: Tx,
  sql: String,
  params: List(value.Value),
) -> Result(@internal Rows, error.Error)

Run a query and return its column names and raw rows.

set_user_version

</>

pub fn set_user_version(
  tx: Tx,
  version: Int,
) -> Result(Nil, error.Error)

Set the database’s user_version.

user_version

</>

pub fn user_version(tx: Tx) -> Result(Int, error.Error)

The database’s user_version, for schema migrations.