TT#5826 introduce contact.timezone column and relevant views

* add billing.contact.timezone column
    * add billing.v_subscriber_timezone view
    * add billing.v_contract_timezone view
    * add billing.v_reseller_timezone view

Change-Id: I7f08c332f28877426991de59b848aa1b635e0b92

db_scripts/diff/15316.down

@@ -0,0 +1,7 @@
+USE billing;
+
+ALTER TABLE contacts DROP timezone;
+
+DROP VIEW v_subscriber_timezone;
+DROP VIEW v_contract_timezone;
+DROP VIEW v_reseller_timezone;

db_scripts/diff/15316.up

@@ -0,0 +1,30 @@
+USE billing;
+
+ALTER TABLE contacts ADD timezone VARCHAR(80) DEFAULT NULL;
+
+CREATE OR REPLACE VIEW v_subscriber_timezone AS
+  SELECT sc.id as contact_id, s.id as subscriber_id, s.uuid,
+         COALESCE(sc.timezone, cc.timezone, rc.timezone) as name
+ FROM voip_subscribers s
+LEFT OUTER JOIN contacts sc ON sc.id = s.contact_id
+JOIN contracts c ON c.id = s.contract_id
+JOIN contacts cc ON cc.id = c.contact_id
+JOIN resellers r ON r.id = cc.reseller_id
+JOIN contracts i ON i.id = r.contract_id
+JOIN contacts rc ON rc.id = i.contact_id;
+
+CREATE OR REPLACE VIEW v_contract_timezone AS
+  SELECT cc.id as contact_id, c.id as contract_id,
+         COALESCE(cc.timezone, rc.timezone) as name
+ FROM contracts c
+JOIN contacts cc ON cc.id = c.contact_id
+JOIN resellers r ON r.id = cc.reseller_id
+JOIN contracts i ON i.id = r.contract_id
+JOIN contacts rc ON rc.id = i.contact_id;
+
+CREATE OR REPLACE VIEW v_reseller_timezone AS
+  SELECT rc.id as contact_id, r.id as reseller_id,
+         rc.timezone as name
+FROM resellers r
+JOIN contracts i ON i.id = r.contract_id
+JOIN contacts rc ON rc.id = i.contact_id;