Cannot add web scenario in Zabbix 3.4.2 with (PostgreSQL 9.6.5)

[MD. ABBAS ALI]

Details:
=============
When I am trying to create a new web scenario in Zabbix 3.4.2 with (PostgreSQL 9.6.5), its failing with the below message:
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Cannot add web scenario
Details

pg_query(): Query failed: ERROR: null value in column "params" violates not-null constraint
DETAIL: Failing row contains (82627, 9, , , 10496, Download speed for scenario "$1"., web.test.in[zabbix-test,,bps], 1m, 30d, 90d, 0, 0, , Bps, , 0, , , , , 0, , null, null, null, , 0, , , , , 0, 0, null, , null, 0, 30d, 0, 0, 0, , 0, , null). [httpconf.php:409 → CFrontendApiWrapper->create() → CApiWrapper->__call() → CFrontendApiWrapper->callMethod() → CApiWrapper->callMethod() → CFrontendApiWrapper->callClientMethod() → CLocalApiClient->callMethod() → call_user_func_array() → CHttpTest->create() → CHttpTestManager->persist() → CHttpTestManager->save() → CHttpTestManager->create() → CHttpTestManager->createHttpTestItems() → DB::insert() → DBexecute() → pg_query() in include/db.inc.php:487]
Error in query [INSERT INTO items (name,key_,value_type,units,hostid,delay,type,hist ory,trends,status,itemid) VALUES ('Download speed for scenario "$1".','web.test.in[zabbix-test,,bps]','0','Bps','10496','1m','9','30d','90d','0','8262 7')] [ERROR: null value in column "params" violates not-null constraint
DETAIL: Failing row contains (82627, 9, , , 10496, Download speed for scenario "$1"., web.test.in[zabbix-test,,bps], 1m, 30d, 90d, 0, 0, , Bps, , 0, , , , , 0, , null, null, null, , 0, , , , , 0, 0, null, , null, 0, 30d, 0, 0, 0, , 0, , null).]
SQL statement execution has failed "INSERT INTO items (name,key_,value_type,units,hostid,delay,type,hist ory,trends,status,itemid) VALUES ('Download speed for scenario "$1".','web.test.in[zabbix-test,,bps]','0','Bps','10496','1m','9','30d','90d','0','8262 7')".
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I have installed zabbix-server(3.4.2) in RedHat 7.3 with PGSQL-9.6.5

N.B.: But I am not facing this issue when creating web scenario with similar version of Zabbix-server(3.4.3) in CentOS 6.5 with MySQL-5.5

[MD. ABBAS ALI]

Actually it was not a Bug.... It was our migration problem.

After modifying PGSQL (Zabbix DB) 'items' Table constraints, Successfully added new Web scenario.

Thanks

[NovaSatori]

I resolved this issue by executing these two commands:
ALTER TABLE items ALTER COLUMN params DROP NOT NULL;
ALTER TABLE items ALTER COLUMN description DROP NOT NULL;

[dimir]

Looks like https://support.zabbix.com/browse/ZBX-13199