Add supporting SQL Server

Dockerfile

@@ -1,5 +1,18 @@
 FROM ruby:2.3.1-slim
-RUN apt-get update -qq && apt-get install -y build-essential libpq-dev libmysqlclient-dev nodejs nodejs-legacy npm git
+RUN apt-get update -qq && \
+    apt-get install -y \
+    build-essential libpq-dev libmysqlclient-dev nodejs nodejs-legacy npm git \
+    freetds-dev freetds-bin unixodbc unixodbc-dev tdsodbc libc6-dev wget
+
+RUN mkdir /tmp/freetds && \
+    cd /tmp/freetds && \
+    wget ftp://ftp.freetds.org/pub/freetds/stable/freetds-1.00.21.tar.gz && \
+    tar -xzf freetds-1.00.21.tar.gz && \
+    cd freetds-1.00.21 && \
+    ./configure --prefix=/usr/local --with-tdsver=7.3 && \
+    make && \
+    make install
+
 RUN mkdir /app
 
 ADD Gemfile /tmp/Gemfile

Gemfile

@@ -7,6 +7,8 @@ gem 'rails', '~> 4.2.6'
 gem 'pg', '~> 0.15'
 gem 'mysql2'
 gem 'activerecord4-redshift-adapter', '~> 0.2.0'
+gem 'activerecord-sqlserver-adapter', '~> 4.2.0'
+gem 'tiny_tds'
 
 gem 'sass-rails', '~> 5.0'
 gem 'uglifier', '>= 1.3.0'

Gemfile.lock

@@ -32,6 +32,8 @@ GEM
       activemodel (= 4.2.7.1)
       activesupport (= 4.2.7.1)
       arel (~> 6.0)
+    activerecord-sqlserver-adapter (4.2.18)
+      activerecord (~> 4.2.1)
     activerecord4-redshift-adapter (0.2.1)
       activerecord (~> 4.2.0)
       pg
@@ -301,6 +303,7 @@ GEM
     thread_safe (0.3.5)
     tilt (2.0.5)
     tins (1.6.0)
+    tiny_tds (2.1.0)
     tzinfo (1.2.2)
       thread_safe (~> 0.1)
     uglifier (3.0.3)
@@ -315,6 +318,7 @@ PLATFORMS
 DEPENDENCIES
   action_args
   active_decorator
+  activerecord-sqlserver-adapter (~> 4.2.0)
   activerecord4-redshift-adapter (~> 0.2.0)
   addressable
   byebug
@@ -354,7 +358,8 @@ DEPENDENCIES
   ruby-prof
   sass-rails (~> 5.0)
   simplecov
+  tiny_tds
   uglifier (>= 1.3.0)
 
 BUNDLED WITH
-   1.12.5
+   1.16.0

app/models/data_source.rb

@@ -75,6 +75,14 @@ def source_table_names
             ) tables
             ORDER BY schemaname, tablename;
           SQL
+        when ActiveRecord::ConnectionAdapters::SQLServerAdapter
+          schemas_and_tables = source_base_class.connection.select_rows(<<-SQL, 'SCHEMA')
+            SELECT table_schema
+                 , table_name
+              FROM information_schema.tables
+             WHERE table_type = 'BASE TABLE';
+          SQL
+          schemas_and_tables.map {|table_schema, table_name| [table_schema, table_name]}
         else
           source_base_class.connection.tables.map {|table_name| [dbname, table_name] }
       end

app/models/data_source_table.rb

@@ -17,9 +17,15 @@ def fetch_rows(limit=20)
     data_source.access_logging do
       adapter = connection.pool.connections.first
       column_names = columns.map {|column| adapter.quote_column_name(column.name) }.join(", ")
-      rows = connection.select_rows(<<-SQL, "#{table_name.classify} Load")
-        SELECT #{column_names} FROM #{adapter.quote_table_name(full_table_name)} LIMIT #{limit};
-      SQL
+      if data_source[:adapter] == 'sqlserver'
+        rows = connection.select_rows(<<-SQL, "#{table_name.classify} Load")
+          SELECT TOP #{limit} #{column_names} FROM #{adapter.quote_table_name(full_table_name)};
+        SQL
+      else
+        rows = connection.select_rows(<<-SQL, "#{table_name.classify} Load")
+          SELECT #{column_names} FROM #{adapter.quote_table_name(full_table_name)} LIMIT #{limit};
+        SQL
+      end
       rows.map {|row|
         columns.zip(row).map {|column, value| column.type_cast_from_database(value) }
       }

app/models/table_memo_raw_dataset_column.rb

@@ -2,12 +2,23 @@ class TableMemoRawDatasetColumn < ActiveRecord::Base
   belongs_to :table_memo_raw_dataset, class_name: "TableMemoRawDataset"
 
   def format_value(value)
-    case sql_type
-    when 'timestamp without time zone'
-      d, t, z = value.to_s.split
-      "#{d} #{t}"
+    datasource_encoding = table_memo_raw_dataset.table_memo.database_memo.data_source.encoding
+    datasource_adapter = table_memo_raw_dataset.table_memo.database_memo.data_source.adapter
+    if datasource_adapter == 'sqlserver'
+      case sql_type
+      when 'timestamp'
+        '0x' + value.unpack('H*')[0]
+      else
+        value.to_s.encode(Encoding.default_internal, datasource_encoding).gsub(/\u0000/, '')
+      end
     else
-      value.to_s
+      case sql_type
+      when 'timestamp without time zone'
+        d, t, z = value.to_s.split
+        "#{d} #{t}"
+      else
+        value.to_s
+      end
     end
   end
 end

app/views/data_sources/_form.html.haml

@@ -8,7 +8,7 @@
       .col-sm-10= f.text_field :description, class: "form-control", placeholder: "localhost database"
     .form-group
       = f.label :adapter, class: "col-sm-2 control-label"
-      .col-sm-10= f.select :adapter, %w(redshift postgresql mysql2), {}, class: "form-control"
+      .col-sm-10= f.select :adapter, %w(redshift postgresql mysql2 sqlserver), {}, class: "form-control"
     .form-group
       = f.label :host, class: "col-sm-2 control-label"
       .col-sm-10= f.text_field :host, class: "form-control", placeholder: "localhost"

config/database.yml

@@ -13,4 +13,5 @@ test:
   database: dmemo_test
 
 production:
+  <<: *default
   url: <%= ENV["DATABASE_URL"] %>