From 4a6459000f2c208bcd66f9158a8d13c1e707d490 Mon Sep 17 00:00:00 2001
From: Miha Mencin <mmencin@biosistemika.com>
Date: Thu, 17 Jan 2019 17:54:15 +0100
Subject: [PATCH] SCI-2936 added migration

---
 ...55006_change_indices_from_int_to_bigint.rb | 41 +++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 db/migrate/20190117155006_change_indices_from_int_to_bigint.rb

diff --git a/db/migrate/20190117155006_change_indices_from_int_to_bigint.rb b/db/migrate/20190117155006_change_indices_from_int_to_bigint.rb
new file mode 100644
index 000000000..d1646ff18
--- /dev/null
+++ b/db/migrate/20190117155006_change_indices_from_int_to_bigint.rb
@@ -0,0 +1,41 @@
+class ChangeIndicesFromIntToBigint < ActiveRecord::Migration[5.1]
+  def up
+  # find primary and foreign keys of type integer throughout the database
+    sql = <<-EOM
+      select tc.table_schema, tc.table_name, kc.column_name, ic.data_type
+      from information_schema.table_constraints tc
+        join information_schema.key_column_usage kc 
+          on kc.table_name = tc.table_name and kc.table_schema = tc.table_schema and kc.constraint_name = tc.constraint_name
+        join information_schema.columns ic
+          on ic.table_schema = tc.table_schema and ic.table_name=tc.table_name and ic.column_name = kc.column_name 
+      where (tc.constraint_type = 'PRIMARY KEY' OR tc.constraint_type = 'FOREIGN KEY')
+        and kc.ordinal_position is not null
+        and ic.data_type = 'integer'
+      order by tc.table_schema,
+               tc.table_name,
+               kc.position_in_unique_constraint;
+    EOM
+
+    # get all user defined views
+    user_viewes = ActiveRecord::Base.connection.execute(
+      "select  *  from pg_views where schemaname = any (current_schemas(false))"
+      )
+
+    # drop all existing views
+    user_viewes.each do |user_view|
+      ActiveRecord::Base.connection.execute("drop view #{user_view['viewname']}")
+    end
+
+    keys = ActiveRecord::Base.connection.execute(sql)
+
+    # change all keys
+    keys.each do |key|
+      change_column key['table_name'], key['column_name'], :bigint
+    end
+
+    # recreate user defined views
+    user_viewes.each do |user_view|
+      ActiveRecord::Base.connection.execute("create view #{user_view['viewname']} as #{user_view['definition']}")
+    end
+  end
+end