postgres syntax error at or near "ON" - sql

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)

Answer 1

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
);

Answer 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