customize case comparision methods to improvie performace

Author: faisalmansoor

activerecord-sqlserver-adapter.gemspec

@@ -24,6 +24,6 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'minitest-spec-rails'
   spec.add_development_dependency 'mocha'
   spec.add_development_dependency 'nokogiri'
-  spec.add_development_dependency 'pry'
+  spec.add_development_dependency 'pry-byebug'
   spec.add_development_dependency 'rake'
 end

bin/console

@@ -0,0 +1,18 @@
+#!/bin/sh
+# Run a Ruby REPL.
+ 
+set -e
+ 
+cd $(dirname "$0")/..
+PRY_PATH=$(which pry)
+echo $PRY_PATH
+ 
+if [ -x $PRY_PATH ] 
+then
+  exec bundle exec $PRY_PATH -Ilib -r activerecord-sqlserver-adapter -r console
+else
+  red='\033[0;31m'
+  NC='\033[0m'
+  echo "${red}Pry was not found or not executable. Make sure \`which pry\` returns an executable.${NC}"
+ 
+fi

lib/active_record/connection_adapters/sqlserver/database_statements.rb

@@ -87,6 +87,22 @@ def case_sensitive_modifier(node, table_attribute)
           Arel::Nodes::Bin.new(node)
         end
 
+        def case_sensitive_comparison(table, attribute, column, value)
+          if column.case_sensitive?
+            table[attribute].eq(value)
+          else
+            super
+          end
+        end
+
+        def case_insensitive_comparison(table, attribute, column, value)
+          if column.case_sensitive?
+            super
+          else
+            table[attribute].eq(value)
+          end
+        end
+
         # === SQLServer Specific ======================================== #
 
         def execute_procedure(proc_name, *variables)

lib/active_record/connection_adapters/sqlserver/schema_statements.rb

@@ -45,7 +45,7 @@ def indexes(table_name, name = nil)
         def columns(table_name, _name = nil)
           return [] if table_name.blank?
           column_definitions(table_name).map do |ci|
-            sqlserver_options = ci.slice :ordinal_position, :is_primary, :is_identity, :default_function, :table_name
+            sqlserver_options = ci.slice :ordinal_position, :is_primary, :is_identity, :default_function, :table_name, :collation
             cast_type = lookup_cast_type(ci[:type])
             new_column ci[:name], ci[:default_value], cast_type, ci[:type], ci[:null], sqlserver_options
           end
@@ -233,6 +233,7 @@ def column_definitions(table_name)
             columns.NUMERIC_SCALE AS numeric_scale,
             columns.NUMERIC_PRECISION AS numeric_precision,
             columns.DATETIME_PRECISION AS datetime_precision,
+            columns.COLLATION_NAME AS collation,
             columns.ordinal_position,
             CASE
               WHEN columns.DATA_TYPE IN ('nchar','nvarchar','char','varchar') THEN columns.CHARACTER_MAXIMUM_LENGTH

lib/active_record/connection_adapters/sqlserver_column.rb

@@ -40,6 +40,14 @@ def is_real?
         @sql_type =~ /real/i
       end
 
+      def collation
+        @sqlserver_options[:collation]
+      end
+
+      def case_sensitive?
+        collation && !collation.match(/_CI/)
+      end
+
     end
   end
 end

lib/console.rb

@@ -0,0 +1,3 @@
+Pry.config.prompt = lambda do |context, nesting, pry| 
+  "[sqlserver] #{context} > "
+end