Use official database name [ci skip]

* s/Postgres/PostgreSQL/
* s/MYSQL/MySQL/, s/Mysql/MySQL/
* s/Sqlite/SQLite/

Replaced all newly added them after 6089b31.

activerecord/CHANGELOG.md

@@ -79,7 +79,7 @@
     bulk deletes by `delete_all`.
 
     Supports skipping or upserting duplicates through the `ON CONFLICT` syntax
-    for Postgres (9.5+) and Sqlite (3.24+) and `ON DUPLICATE KEY UPDATE` syntax
+    for PostgreSQL (9.5+) and SQLite (3.24+) and `ON DUPLICATE KEY UPDATE` syntax
     for MySQL.
 
     *Bob Lail*

activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb

@@ -966,7 +966,7 @@ module ActiveRecord
       # [<tt>:on_update</tt>]
       #   Action that happens <tt>ON UPDATE</tt>. Valid values are +:nullify+, +:cascade+ and +:restrict+
       # [<tt>:validate</tt>]
-      #   (Postgres only) Specify whether or not the constraint should be validated. Defaults to +true+.
+      #   (PostgreSQL only) Specify whether or not the constraint should be validated. Defaults to +true+.
       def add_foreign_key(from_table, to_table, options = {})
         return unless supports_foreign_keys?
 

activerecord/lib/active_record/integration.rb

@@ -180,7 +180,7 @@ module ActiveRecord
       #   raw_timestamp_to_cache_version(timestamp)
       #   # => "20181015200215266505"
       #
-      # Postgres truncates trailing zeros,
+      # PostgreSQL truncates trailing zeros,
       # https://github.com/postgres/postgres/commit/3e1beda2cde3495f41290e1ece5d544525810214
       # to account for this we pad the output with zeros
       def raw_timestamp_to_cache_version(timestamp)

activerecord/lib/active_record/persistence.rb

@@ -85,14 +85,14 @@ module ActiveRecord
       # ==== Options
       #
       # [:returning]
-      #   (Postgres-only) An array of attributes to return for all successfully
+      #   (PostgreSQL only) An array of attributes to return for all successfully
       #   inserted records, which by default is the primary key.
       #   Pass <tt>returning: %w[ id name ]</tt> for both id and name
       #   or <tt>returning: false</tt> to omit the underlying <tt>RETURNING</tt> SQL
       #   clause entirely.
       #
       # [:unique_by]
-      #   (Postgres and SQLite only) By default rows are considered to be unique
+      #   (PostgreSQL and SQLite only) By default rows are considered to be unique
       #   by every unique index on the table. Any duplicate rows are skipped.
       #
       #   To skip rows according to just one unique index pass <tt>:unique_by</tt>.
@@ -154,7 +154,7 @@ module ActiveRecord
       # ==== Options
       #
       # [:returning]
-      #   (Postgres-only) An array of attributes to return for all successfully
+      #   (PostgreSQL only) An array of attributes to return for all successfully
       #   inserted records, which by default is the primary key.
       #   Pass <tt>returning: %w[ id name ]</tt> for both id and name
       #   or <tt>returning: false</tt> to omit the underlying <tt>RETURNING</tt> SQL
@@ -202,14 +202,14 @@ module ActiveRecord
       # ==== Options
       #
       # [:returning]
-      #   (Postgres-only) An array of attributes to return for all successfully
+      #   (PostgreSQL only) An array of attributes to return for all successfully
       #   inserted records, which by default is the primary key.
       #   Pass <tt>returning: %w[ id name ]</tt> for both id and name
       #   or <tt>returning: false</tt> to omit the underlying <tt>RETURNING</tt> SQL
       #   clause entirely.
       #
       # [:unique_by]
-      #   (Postgres and SQLite only) By default rows are considered to be unique
+      #   (PostgreSQL and SQLite only) By default rows are considered to be unique
       #   by every unique index on the table. Any duplicate rows are skipped.
       #
       #   To skip rows according to just one unique index pass <tt>:unique_by</tt>.

activerecord/test/cases/adapters/mysql2/schema_test.rb

@@ -41,7 +41,7 @@ module ActiveRecord
         column_24 = @connection.columns(:mysql_doubles).find { |c| c.name == "float_24" }
         column_25 = @connection.columns(:mysql_doubles).find { |c| c.name == "float_25" }
 
-        # Mysql floats are precision 0..24, Mysql doubles are precision 25..53
+        # MySQL floats are precision 0..24, MySQL doubles are precision 25..53
         assert_equal 24, column_no_limit.limit
         assert_equal 24, column_short.limit
         assert_equal 53, column_long.limit

guides/source/active_record_basics.md

@@ -105,7 +105,7 @@ depending on the purpose of these columns.
   fields that Active Record will look for when you create associations between
   your models.
 * **Primary keys** - By default, Active Record will use an integer column named
-  `id` as the table's primary key (`bigint` for Postgres and MYSQL, `integer`
+  `id` as the table's primary key (`bigint` for PostgreSQL and MySQL, `integer`
   for SQLite). When using [Active Record Migrations](active_record_migrations.html)
   to create your tables, this column will be automatically created.
 

guides/source/i18n.md

@@ -1206,7 +1206,7 @@ The I18n API described in this guide is primarily intended for translating inter
 Several gems can help with this:
 
 * [Globalize](https://github.com/globalize/globalize): Store translations on separate translation tables, one for each translated model
-* [Mobility](https://github.com/shioyama/mobility): Provides support for storing translations in many formats, including translation tables, json columns (Postgres), etc.
+* [Mobility](https://github.com/shioyama/mobility): Provides support for storing translations in many formats, including translation tables, json columns (PostgreSQL), etc.
 * [Traco](https://github.com/barsoom/traco): Translatable columns for Rails 3 and 4, stored in the model table itself
 
 Conclusion