Update with where clause

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Update with where clause

The update mode allows to update existing rows. You can use the --where flag (or -w) to specify a SQL WHERE clause. The update will only be performed if the condition matches.

$ lino push update dest --where "last_update > '2023-01-01'" < data.jsonl

The clause is added to the update query with an AND operator, combining it with the primary key condition.

Important: The --where clause is applied only to the start table of the push operation. If the push operation involves multiple tables (via recursion in the ingress descriptor), the condition will not be applied to child or parent tables.

Difference with __usingpk__

• __usingpk__ is used to target a specific row to update when the primary key itself is being modified. It provides the "old" primary key to locate the record.
• --where is used to add a logical condition to the update. It is useful for:
  • Optimistic locking: Update only if the record hasn't changed since last read (e.g. version = 1).
  • Business rules: Update only if the record is in a specific state (e.g. status = 'PENDING').

Both can be used together. __usingpk__ identifies which row to try to update, and --where adds an additional check to decide if the update should proceed.