Committed calls f after committed or immediate if not in tx.

Exec calls db.ExecContext.

IsInTx checks is context inside RunInTx.

Iter calls pgsql.IterContext.

Middleware injects db into request's context.

NewContext creates new context.

Prepare calls db.PrepareContext.

Query calls db.QueryContext.

QueryRow calls db.QueryRowContext.

RunInReadOnlyTx calls RunInTxOptions with read only options.

RunInTx calls RunInTxOptions with default options.

RunInTxOptions starts sql tx if not started.

With creates new empty key context with db from keyed context.

Queryer interface.