PgForLocking

class PgForLocking(kind)

A FOR locking clause. Created via SQL.for_locking(kind). Inherits from SqlObj.

Parameters:

kind – Lock strength string — 'UPDATE', 'NO KEY UPDATE', 'SHARE', or 'KEY SHARE'.

SQL.for_locking('UPDATE')
# FOR UPDATE

SQL.for_locking('NO KEY UPDATE')
# FOR NO KEY UPDATE

of(*expr)

Restrict locking to specific tables.

Parameters:

expr – One or more table name strings.

SQL.for_locking('UPDATE').of('employees')
# FOR UPDATE OF employees

SQL.for_locking('UPDATE').of('employees', 'tasks')
# FOR UPDATE OF employees, tasks

locking(expr)

Set wait policy.

Parameters:

expr – Wait policy string — 'NOWAIT' or 'SKIP LOCKED'.

SQL.for_locking('UPDATE').locking('NOWAIT')
# FOR UPDATE NOWAIT

SQL.for_locking('UPDATE').of('t1').locking('SKIP LOCKED')
# FOR UPDATE OF t1 SKIP LOCKED