Let's say you have an intrinsic safety application and you may wish to not only ignore the conflict, but report it by failing and stopping the entire transaction (and return a FAIL response in the API), then you would say: "INSERT OR FAIL. The way to say that is: "INSERT OR IGNORE INTO. One way of handling that conflict is to say "If I try to add a row that causes a conflict, please ignore my attempt and continue as if nothing changed" - aka, "IGNORE it". In a database it can easily be less than Zero, unless you place that constraint rule on the column by adding, for instance.Ī unique key is a constraint too, so if you declare a column as UNIQUE or PRIMARY KEY or such, you say "This column can never contain duplicate values", so when you try to insert a row with the exact same value for that column than an existing row, a constraint failure happens, which is called a "conflict" and which could be handled in several different ways.
SQLITE INSERT UPDATE ON DUPLICATE KEY HOW TO
it tells the engine how to handle conflicts.Ī conflict is when you are trying to add/insert/update something that causes a constraint to fail.Ī constraint is a clear rule you've added to the database.Īn example of a real life constraint is that any human's Age can never be less than Zero. " clause is a conflict handling directive, i.e. The "OR IGNORE" part of the "INSERT OR IGNORE. This may be boring to seasoned users, so consider TLDR warning issued. I've seen now quite a few questions in this thread, so thought it prudent to elaborate on conflict resolution. In some narrowly defined and specific implementations with very particular database schema constructions they made achieve the same result, but that is only by happenstance and sheer luck. One does an UPDATE when a matching conflict is found, the other DELETEs conflicting rows and does an insert, which are entirely different things. because they behave entirely differently. That is, "INSERT or REPLACE" is not and never will be equivalent to any INSERT.
INSERT INTO x VALUES (.) ON CONFLICT DO NOTHING īecause one prefers using ON CONFLICT resolution clauses rather than the "or IGNORE" clause, however the ON CONFLICT clause does not (and cannot) equate to the "or REPLACE"/"or ROLLBACK"/"or ABORT"/"or FAIL" clauses. Though I don't really understand why you would do that - it seems rather foolish to me. INSERT or REPLACE INTO x VALUES (.) ON CONFLICT DO NOTHING Īnd indeed the "last seen" conflict resolution method (ON CONFLICT) overrides the prior resolution method (or REPLACE). Which is of course an alternate spelling for REPLACE INTO x VALUES (.) ON CONFLICT DO NOTHING Yes, you can apparently specify something ludicrous like:
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