INSERT IF NOT EXISTS ELSE UPDATE?

user_1766790 0
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I've found a few "would be" solutions for the classic "How do I insert a new record or update one if it already exists" but I cannot get any of them to work in SQLite.

I have a table defined as follows:

CREATE TABLE Book 
ID     INTEGER PRIMARY KEY AUTOINCREMENT,
Name   VARCHAR(60) UNIQUE,
TypeID INTEGER,
Level  INTEGER,
Seen   INTEGER

What I want to do is add a record with a unique Name. If the Name already exists, I want to modify the fields.

Can somebody tell me how to do this please?

merge-conflict-resolution insert exists upsert sqlite
9 Answers

You should use the INSERT OR IGNORE command followed by an UPDATE command: In the following example name is a primary key:

INSERT OR IGNORE INTO my_table (name, age) VALUES ('Karen', 34)
UPDATE my_table SET age = 34 WHERE name='Karen'

The first command will insert the record. If the record exists, it will ignore the error caused by the conflict with an existing primary key.

The second command will update the record (which now definitely exists)

user_30541280

You need to set a constraint on the table to trigger a "conflict" which you then resolve by doing a replace:

CREATE TABLE data   (id INTEGER PRIMARY KEY, event_id INTEGER, track_id INTEGER, value REAL);
CREATE UNIQUE INDEX data_idx ON data(event_id, track_id);

Then you can issue:

INSERT OR REPLACE INTO data VALUES (NULL, 1, 2, 3);
INSERT OR REPLACE INTO data VALUES (NULL, 2, 2, 3);
INSERT OR REPLACE INTO data VALUES (NULL, 1, 2, 5);

The "SELECT * FROM data" will give you:

2|2|2|3.0
3|1|2|5.0

Note that the data.id is "3" and not "1" because REPLACE does a DELETE and INSERT, not an UPDATE. This also means that you must ensure that you define all necessary columns or you will get unexpected NULL values.

user_2521240

Upsert is what you want. UPSERT syntax was added to SQLite with version 3.24.0 (2018-06-04).

CREATE TABLE phonebook2(
  name TEXT PRIMARY KEY,
  phonenumber TEXT,
  validDate DATE
);

INSERT INTO phonebook2(name,phonenumber,validDate)
  VALUES('Alice','704-555-1212','2018-05-08')
  ON CONFLICT(name) DO UPDATE SET
    phonenumber=excluded.phonenumber,
    validDate=excluded.validDate
  WHERE excluded.validDate>phonebook2.validDate;

Be warned that at this point the actual word "UPSERT" is not part of the upsert syntax.

The correct syntax is

INSERT INTO ... ON CONFLICT(...) DO UPDATE SET...

and if you are doing INSERT INTO SELECT ... your select needs at least WHERE true to solve parser ambiguity about the token ON with the join syntax.

Be warned that INSERT OR REPLACE... will delete the record before inserting a new one if it has to replace, which could be bad if you have foreign key cascades or other delete triggers.

user_42624660
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