postgres syntax error at or near "ON"

Question

I created this table:

CREATE TABLE IF NOT EXISTS config_activity_log
(
  id                      serial primary key,
  activity_name           varchar(100) NOT NULL,
  last_config_version     varchar(50) NOT NULL,
  activity_status         varchar(100) NOT NULL DEFAULT 'Awaiting for cofman',
  cofman_last_update      bigint NOT NULL DEFAULT -1,
  is_error                boolean DEFAULT FALSE,
  activity_timestamp      timestamp DEFAULT current_timestamp
);

I try to run this postgres script:

INSERT INTO config_activity_log
    (activity_name, last_config_version, activity_status)
VALUES
    ('test awating deployment','5837-2016-08-24_09-12-22', 'Awaiting for deployment')
ON CONFLICT (activity_name)
DO UPDATE SET
    activity_status = EXCLUDED.activity_status

why do i get this syntax error?

psql:upsert_test_log.sql:7: ERROR:  syntax error at or near "ON"
LINE 5: ON CONFLICT (activity_name)

PSQL docs say that if using brackets on "ON CONFLICT" the thing inside is an index expression. Is activity_name an index expression, or is it just a column ? https://www.postgresql.org/docs/9.5/static/sql-insert.html — Neil Stockton, Oct 30 '16 at 09:01
just column. "id" is an index column but it's auto populated. how can i fix this? — Elad Benda2, Oct 30 '16 at 09:02
Do you have a unique index on `activity_name` that would cause a conflict? — JohnLBevan, Oct 30 '16 at 09:05
no, i have added my table creation script. activity_name has no index nor it's unique — Elad Benda2, Oct 30 '16 at 09:06
If the `activity_name` doesn't have a unique constraint, there can't be a conflict on that field (i.e. what is there for it to conflict with if there's no constraint?). By adding a unique index on that column the conflict action makes sense, so should then work. — JohnLBevan, Oct 30 '16 at 09:08
`on conflict` was introduced in Postgres 9.5. Your Postgres version? — klin, Oct 30 '16 at 09:08
See `conflict_target` in https://www.postgresql.org/docs/9.5/static/sql-insert.html#SQL-ON-CONFLICT — JohnLBevan, Oct 30 '16 at 09:09
@JohnLBevan So maybe i need another solution. usually activity_name is not unique, but I want to add a "test" row with status "a". when it changes to "b" I want to alter it to "a" instead of adding a new test row — Elad Benda2, Oct 30 '16 at 09:17

score 16 · Accepted Answer · edited May 23 '17 at 11:47

Supported Version

Per @klin's comment above, ON CONFLICT is only supported from PostgreSQL 9.5 onwards.

If you're on an earlier version, there's some great info in this answer: https://stackoverflow.com/a/17267423/361842

Unique Constraint

Add a unique index on activity_name. At present there's no constraints on that column, so there's no possibility for a conflict on that column.

CREATE UNIQUE INDEX UK_config_activity_log__activity_name 
ON config_activity_log (activity_name);

If, however, you don't want that column to be unique, what conflict are you envisaging / what's the issue you're hoping to resolve with the on conflict action?

See conflict_target in https://www.postgresql.org/docs/9.5/static/sql-insert.html#SQL-ON-CONFLICT

An alternative syntax is to modify your create statement to include the unique condition there; e.g.

CREATE TABLE IF NOT EXISTS config_activity_log
(
  id                      serial primary key,
  activity_name           varchar(100) NOT NULL UNIQUE,
  last_config_version     varchar(50) NOT NULL,
  activity_status         varchar(100) NOT NULL DEFAULT 'Awaiting for cofman',
  cofman_last_update      bigint NOT NULL DEFAULT -1,
  is_error                boolean DEFAULT FALSE,
  activity_timestamp      timestamp DEFAULT current_timestamp
);

So maybe i need another solution. usually `activity_name` is not unique, but I want to add a "test" row with status "a". when it changes to "b" I want to alter it to "a" instead of adding a new test row — Elad Benda2, Oct 30 '16 at 09:16
If I've understood, that means `activity_name` is still unique. i.e. you have one row where `activity_name`=`'test'` and `activity_status`=`'a'`. You attempt to insert a second row where `activity_name`=`'test'` and `activity_status`=`'b'`, but in this case since a row with the same `activity_name` already exists you want it to update `activity_status` to `'b'` instead of creating a new row; i.e. at any time the database will only hold 1 row with `activity_name`=`'test'`. — JohnLBevan, Oct 30 '16 at 09:22

David דודו Markovitz · Answer 2 · 2016-10-30T09:32:13.993

2

According to the error code, your version does not support ON CONFLICT.
On PostreSQL 9.6 the error message is -

[Code: 0, SQL State: 42P10]  ERROR: there is no unique or exclusion constraint matching the ON CONFLICT specification

edited Oct 30 '16 at 09:32

answered Oct 30 '16 at 09:14

David דודו Markovitz

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So maybe i need another solution. usually activity_name is not unique, but I want to add a "test" row with status "a". when it changes to "b" I want to alter it to "a" instead of adding a new test row – Elad Benda2 Oct 30 '16 at 09:17
@EladBenda2, this is not clear. Could you add a scenario for example to your question? – David דודו Markovitz Oct 30 '16 at 09:24

postgres syntax error at or near "ON"

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