Multiple enhancements and adjustments to DB2 adaptor. Closes #3377.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3380 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

7 files changed, 207 insertions, 169 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 3b53432cc6..590f4d8300 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Multiple enhancements and adjustments to DB2 adaptor. #3377 [contact@maik-schmidt.de]
+
 * Sanitize scoped conditions. [Marcel Molina Jr.]
 
 * Added option to Base.reflection_of_all_associations to specify a specific association to scope the call. For example Base.reflection_of_all_associations(:has_many) [DHH]
diff --git a/activerecord/lib/active_record/connection_adapters/db2_adapter.rb b/activerecord/lib/active_record/connection_adapters/db2_adapter.rb
index 232971e4ec..7e3627261a 100644
--- a/activerecord/lib/active_record/connection_adapters/db2_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/db2_adapter.rb
@@ -14,16 +14,17 @@ begin
         config = config.symbolize_keys
         usr = config[:username]
         pwd = config[:password]
+        schema = config[:schema]
 
         if config.has_key?(:database)
           database = config[:database]
         else
-          raise ArgumentError, "No database specified. Missing argument: database."
+          raise ArgumentError, 'No database specified. Missing argument: database.'
         end
 
         connection = DB2::Connection.new(DB2::Environment.new)
         connection.connect(database, usr, pwd)
-        ConnectionAdapters::DB2Adapter.new(connection)
+        ConnectionAdapters::DB2Adapter.new(connection, logger, :schema => schema)
       end
     end
 
@@ -35,7 +36,18 @@ begin
       # * <tt>:username</tt> -- Defaults to nothing
       # * <tt>:password</tt> -- Defaults to nothing
       # * <tt>:database</tt> -- The name of the database. No default, must be provided.
+      # * <tt>:schema</tt> -- Database schema to be set initially.
       class DB2Adapter < AbstractAdapter
+        def initialize(connection, logger, connection_options)
+          super(connection, logger)
+          @connection_options = connection_options
+          if schema = @connection_options[:schema]
+            with_statement do |stmt|
+              stmt.exec_direct("SET SCHEMA=#{schema}")
+            end
+          end
+        end
+        
         def select_all(sql, name = nil)
           select(sql, name)
         end
@@ -51,14 +63,12 @@ begin
 
         def execute(sql, name = nil)
           rows_affected = 0
-
-          log(sql, name) do
-            stmt = DB2::Statement.new(@connection)
-            stmt.exec_direct(sql)
-            rows_affected = stmt.row_count
-            stmt.free
+          with_statement do |stmt|
+            log(sql, name) do
+              stmt.exec_direct(sql)
+              rows_affected = stmt.row_count
+            end
           end
-
           rows_affected
         end
 
@@ -92,64 +102,68 @@ begin
         end
 
         def add_limit_offset!(sql, options)
-          if options[:limit] and !options[:limit].nil?
-            # "FETCH FIRST 0 ROWS ONLY" is not allowed, so we have
-            # to use a cheap trick.
-            if options[:limit] == 0
-              if sql =~ /WHERE/i
-                sql.sub!(/WHERE/i, 'WHERE 1 = 2 AND ')
-              elsif
-                sql =~ /ORDER\s+BY/i
-                sql.sub!(/ORDER\s+BY/i, 'WHERE 1 = 2 ORDER BY')
-              else
-                sql << 'WHERE 1 = 2'
-              end
-            else
-              sql << " FETCH FIRST #{options[:limit]} ROWS ONLY" 
-            end
-          end
-          if options[:offset] and !options[:offset].nil?
-            raise ArgumentError, ':offset option is not yet supported!'
+          if limit = options[:limit]
+            offset = options[:offset] || 0
+            # The following trick was added by andrea+rails@webcom.it.
+            sql.gsub!(/SELECT/i, 'SELECT B.* FROM (SELECT A.*, row_number() over () AS internal$rownum FROM (SELECT')
+            sql << ") A ) B WHERE B.internal$rownum > #{offset} AND B.internal$rownum <= #{limit + offset}"
           end
         end
 
         def tables(name = nil)
-          stmt = DB2::Statement.new(@connection)
           result = []
-          stmt.tables.each { |t| result << t[2].downcase }
-          stmt.free
+          with_statement do |stmt|
+            stmt.tables.each { |t| result << t[2].downcase }
+          end
           result
         end
 
+        def indexes(table_name, name = nil)
+          tmp = {}
+          with_statement do |stmt|
+            stmt.indexes(table_name.upcase).each do |t|
+              next unless t[5]
+              next if t[4] == 'SYSIBM' # Skip system indexes.
+              idx_name = t[5].downcase
+              col_name = t[8].downcase
+              if tmp.has_key?(idx_name)
+                tmp[idx_name].columns << col_name
+              else
+                is_unique = t[3] == 0
+                tmp[idx_name] = IndexDefinition.new(table_name, idx_name, is_unique, [col_name])
+              end
+            end
+          end
+          tmp.values
+        end
+
         def columns(table_name, name = nil)
-          stmt = DB2::Statement.new(@connection)
           result = []
-
-          stmt.columns(table_name.upcase).each do |c| 
-            c_name = c[3].downcase
-            c_default = c[12] == 'NULL' ? nil : c[12]
-            c_type = c[5].downcase
-            c_type += "(#{c[6]})" if !c[6].nil? && c[6] != ''
-            result << Column.new(c_name, c_default, c_type)
-          end 
-
-          stmt.free
+          with_statement do |stmt|
+            stmt.columns(table_name.upcase).each do |c| 
+              c_name = c[3].downcase
+              c_default = c[12] == 'NULL' ? nil : c[12]
+              c_type = c[5].downcase
+              c_type += "(#{c[6]})" if !c[6].nil? && c[6] != ''
+              result << Column.new(c_name, c_default, c_type)
+            end 
+          end
           result
         end
 
         def native_database_types
           {
-            :primary_key => "int generated by default as identity primary key",
-            :string      => { :name => "varchar", :limit => 255 },
-            :text        => { :name => "clob", :limit => 32768 },
-            :integer     => { :name => "int" },
-            :float       => { :name => "float" },
-            :datetime    => { :name => "timestamp" },
-            :timestamp   => { :name => "timestamp" },
-            :time        => { :name => "time" },
-            :date        => { :name => "date" },
-            :binary      => { :name => "blob", :limit => 32768 },
-            :boolean     => { :name => "decimal", :limit => 1 }
+            :primary_key => 'int generated by default as identity primary key',
+            :string      => { :name => 'varchar', :limit => 255 },
+            :text        => { :name => 'clob', :limit => 32768 },
+            :integer     => { :name => 'int' },
+            :float       => { :name => 'float' },
+            :datetime    => { :name => 'timestamp' },
+            :timestamp   => { :name => 'timestamp' },
+            :time        => { :name => 'time' },
+            :date        => { :name => 'date' },
+            :binary      => { :name => 'blob', :limit => 32768 },
+            :boolean     => { :name => 'decimal', :limit => 1 }
           }
         end
 
@@ -161,8 +175,24 @@ begin
           '0'
         end
 
+        def active?
+          @connection.select_one 'select 1 from ibm.sysdummy1'
+          true
+        rescue Exception
+          false
+        end
+
+        def reconnect!
+        end
+
         private
 
+        def with_statement
+          stmt = DB2::Statement.new(@connection)
+          yield stmt
+          stmt.free
+        end
+
         def last_insert_id
           row = select_one(<<-GETID.strip)
           with temp(id) as (values (identity_val_local())) select * from temp
@@ -171,17 +201,17 @@ begin
         end
 
         def select(sql, name = nil)
-          stmt = nil
-          log(sql, name) do
-            stmt = DB2::Statement.new(@connection)
-            stmt.exec_direct("#{sql.gsub(/=\s*null/i, 'IS NULL')} with ur")
-          end
-
           rows = []
-          while row = stmt.fetch_as_hash
-            rows << row
+          with_statement do |stmt|
+            log(sql, name) do
+              stmt.exec_direct("#{sql.gsub(/=\s*null/i, 'IS NULL')} with ur")
+            end
+
+            while row = stmt.fetch_as_hash
+              row.delete('internal$rownum')
+              rows << row
+            end
           end
-          stmt.free
           rows
         end
       end
diff --git a/activerecord/lib/active_record/vendor/db2.rb b/activerecord/lib/active_record/vendor/db2.rb
index 42171beda8..5ebd348a0a 100644
--- a/activerecord/lib/active_record/vendor/db2.rb
+++ b/activerecord/lib/active_record/vendor/db2.rb
@@ -110,13 +110,18 @@ module DB2
       check_rc(rc)
     end
 
-    def columns(table_name)
-      check_rc(SQLColumns(@handle, "", "%", table_name, "%"))
+    def columns(table_name, schema_name = '%')
+      check_rc(SQLColumns(@handle, '', schema_name, table_name, '%'))
       fetch_all
     end
 
     def tables
-      check_rc(SQLTables(@handle, "", "%", "%", "TABLE"))
+      check_rc(SQLTables(@handle, '', '%', '%', 'TABLE'))
+      fetch_all
+    end
+
+    def indexes(table_name)
+      check_rc(SQLStatistics(@handle, '', '', table_name, SQL_INDEX_ALL, SQL_ENSURE))
       fetch_all
     end
 
diff --git a/activerecord/test/adapter_test.rb b/activerecord/test/adapter_test.rb
index 7d427cda50..034e9ac45a 100644
--- a/activerecord/test/adapter_test.rb
+++ b/activerecord/test/adapter_test.rb
@@ -19,13 +19,14 @@ class AdapterTest < Test::Unit::TestCase
 
   def test_indexes
     if @connection.respond_to?(:indexes)
+      idx_name = "accounts_idx"
       indexes = @connection.indexes("accounts")
       assert indexes.empty?
 
-      @connection.add_index :accounts, :firm_id
+      @connection.add_index :accounts, :firm_id, :name => idx_name
       indexes = @connection.indexes("accounts")
       assert_equal "accounts", indexes.first.table
-      assert_equal "accounts_firm_id_index", indexes.first.name
+      assert_equal idx_name, indexes.first.name
       assert !indexes.first.unique
       assert_equal ["firm_id"], indexes.first.columns
     else
diff --git a/activerecord/test/associations_join_model_test.rb b/activerecord/test/associations_join_model_test.rb
index f385bd2175..f8d8b77813 100644
--- a/activerecord/test/associations_join_model_test.rb
+++ b/activerecord/test/associations_join_model_test.rb
@@ -40,7 +40,7 @@ class AssociationsJoinModelTest < Test::Unit::TestCase
   end
   
   def test_has_many_with_piggyback
-    assert_equal "2", categories(:sti_test).authors.first.post_id
+    assert_equal "2", categories(:sti_test).authors.first.post_id.to_s
   end
   
   def test_has_many_find_all
diff --git a/activerecord/test/fixtures/db_definitions/db2.sql b/activerecord/test/fixtures/db_definitions/db2.sql
index 49f31aba67..c50e7178f8 100644
--- a/activerecord/test/fixtures/db_definitions/db2.sql
+++ b/activerecord/test/fixtures/db_definitions/db2.sql
@@ -1,196 +1,196 @@
 CREATE TABLE accounts (
-  id int generated by default as identity (start with +10000),
-  firm_id int default NULL,
-  credit_limit int default NULL,
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  firm_id INT DEFAULT NULL,
+  credit_limit INT DEFAULT NULL,
   PRIMARY KEY (id)
 );
 
 CREATE TABLE companies (
-  id int generated by default as identity (start with +10000),
-  type varchar(50) default NULL,
-  ruby_type varchar(50) default NULL,
-  firm_id int default NULL,
-  name varchar(50) default NULL,
-  client_of int default NULL,
-  rating int default 1,
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  type VARCHAR(50) DEFAULT NULL,
+  ruby_type VARCHAR(50) DEFAULT NULL,
+  firm_id INT DEFAULT NULL,
+  name VARCHAR(50) DEFAULT NULL,
+  client_of INT DEFAULT NULL,
+  rating INT DEFAULT 1,
   PRIMARY KEY (id)
 );
 
 CREATE TABLE topics (
-  id int generated by default as identity (start with +10000),
-  title varchar(255) default NULL,
-  author_name varchar(255) default NULL,
-  author_email_address varchar(255) default NULL,
-  written_on timestamp default NULL,
-  bonus_time time default NULL,
-  last_read date default NULL,
-  content varchar(3000),
-  approved smallint default 1,
-  replies_count int default 0,
-  parent_id int default NULL,
-  type varchar(50) default NULL,
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  title VARCHAR(255) DEFAULT NULL,
+  author_name VARCHAR(255) DEFAULT NULL,
+  author_email_address VARCHAR(255) DEFAULT NULL,
+  written_on TIMESTAMP DEFAULT NULL,
+  bonus_time TIME DEFAULT NULL,
+  last_read DATE DEFAULT NULL,
+  content VARCHAR(3000),
+  approved SMALLINT DEFAULT 1,
+  replies_count INT DEFAULT 0,
+  parent_id INT DEFAULT NULL,
+  type VARCHAR(50) DEFAULT NULL,
   PRIMARY KEY (id)
 );
 
 CREATE TABLE developers (
-  id int generated by default as identity (start with +10000),
-  name varchar(100) default NULL,
-  salary int default 70000,
-  created_at timestamp default NULL,
-  updated_at timestamp default NULL,
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  name VARCHAR(100) DEFAULT NULL,
+  salary INT DEFAULT 70000,
+  created_at TIMESTAMP DEFAULT NULL,
+  updated_at TIMESTAMP DEFAULT NULL,
   PRIMARY KEY (id)
 );
 
 CREATE TABLE projects (
-  id int generated by default as identity (start with +10000),
-  name varchar(100) default NULL,
-  type varchar(255) default NULL,
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  name VARCHAR(100) DEFAULT NULL,
+  type VARCHAR(255) DEFAULT NULL,
   PRIMARY KEY (id)
 );
 
 CREATE TABLE developers_projects (
-  developer_id int NOT NULL,
-  project_id int NOT NULL,
-  joined_on date default NULL,
-  access_level smallint default 1
+  developer_id INT NOT NULL,
+  project_id INT NOT NULL,
+  joined_on DATE DEFAULT NULL,
+  access_level SMALLINT DEFAULT 1
 );
 
 CREATE TABLE orders (
-  id int generated by default as identity (start with +10000),
-  name varchar(100) default NULL,
-  billing_customer_id int default NULL,
-  shipping_customer_id int default NULL,
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  name VARCHAR(100) DEFAULT NULL,
+  billing_customer_id INT DEFAULT NULL,
+  shipping_customer_id INT DEFAULT NULL,
   PRIMARY KEY (id)
 );
 
 CREATE TABLE customers (
-  id int generated by default as identity (start with +10000),
-  name varchar(100) default NULL,
-  balance int default 0,
-  address_street varchar(100) default NULL,
-  address_city varchar(100) default NULL,
-  address_country varchar(100) default NULL,
-  gps_location varchar(100) default NULL,
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  name VARCHAR(100) DEFAULT NULL,
+  balance INT DEFAULT 0,
+  address_street VARCHAR(100) DEFAULT NULL,
+  address_city VARCHAR(100) DEFAULT NULL,
+  address_country VARCHAR(100) DEFAULT NULL,
+  gps_location VARCHAR(100) DEFAULT NULL,
   PRIMARY KEY (id)
 );
 
 CREATE TABLE movies (
-  movieid int generated by default as identity (start with +10000),
-  name varchar(100) default NULL,
+  movieid INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  name VARCHAR(100) DEFAULT NULL,
   PRIMARY KEY (movieid)
 );
 
 CREATE TABLE subscribers (
-  nick varchar(100) NOT NULL,
-  name varchar(100) default NULL,
+  nick VARCHAR(100) NOT NULL,
+  name VARCHAR(100) DEFAULT NULL,
   PRIMARY KEY (nick)
 );
 
 CREATE TABLE booleantests (
-  id int generated by default as identity (start with +10000),
-  value int default NULL,
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  value INT DEFAULT NULL,
   PRIMARY KEY (id)
 );
 
 CREATE TABLE auto_id_tests (
-  auto_id int generated by default as identity (start with +10000),
-  value int default NULL,
+  auto_id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  value INT DEFAULT NULL,
   PRIMARY KEY (auto_id)
 );
 
 CREATE TABLE entrants (
-  id int NOT NULL PRIMARY KEY,
-  name varchar(255) NOT NULL,
-  course_id int NOT NULL
+  id INT NOT NULL PRIMARY KEY,
+  name VARCHAR(255) NOT NULL,
+  course_id INT NOT NULL
 );
 
 CREATE TABLE colnametests (
-  id int generated by default as identity (start with +10000),
-  references int NOT NULL,
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  references INT NOT NULL,
   PRIMARY KEY (id)
 );
 
 CREATE TABLE mixins (
-  id int generated by default as identity (start with +10000),
-  parent_id int default NULL,
-  pos int default NULL,
-  created_at timestamp default NULL,
-  updated_at timestamp default NULL,
-  lft int default NULL,
-  rgt int default NULL,
-  root_id int default NULL,
-  type varchar(40) default NULL,
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  parent_id INT DEFAULT NULL,
+  pos INT DEFAULT NULL,
+  created_at TIMESTAMP DEFAULT NULL,
+  updated_at TIMESTAMP DEFAULT NULL,
+  lft INT DEFAULT NULL,
+  rgt INT DEFAULT NULL,
+  root_id INT DEFAULT NULL,
+  type VARCHAR(40) DEFAULT NULL,
   PRIMARY KEY (id)
 );
 
 CREATE TABLE people (
-  id int generated by default as identity (start with +10000),
-  first_name varchar(40) NOT NULL,
-  lock_version int default 0,
-  PRIMARY KEY  (id)
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  first_name VARCHAR(40) NOT NULL,
+  lock_version INT DEFAULT 0,
+  PRIMARY KEY (id)
 );
 
 CREATE TABLE binaries (
-  id int generated by default as identity (start with +10000),
-  data blob(50000),
-  PRIMARY KEY  (id)
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  data BLOB(50000),
+  PRIMARY KEY (id)
 );
 
 CREATE TABLE computers (
-  id int generated by default as identity (start with +10000),
-  developer int NOT NULL,
-  extendedWarranty int NOT NULL
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  developer INT NOT NULL,
+  extendedWarranty INT NOT NULL
 );
 
 CREATE TABLE posts (
-  id int generated by default as identity (start with +10000),
-  author_id int default NULL,
-  title varchar(255) default NULL,
-  type varchar(255) default NULL,
-  body varchar(3000) default NULL
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  author_id INT DEFAULT NULL,
+  title VARCHAR(255) DEFAULT NULL,
+  type VARCHAR(255) DEFAULT NULL,
+  body VARCHAR(3000) DEFAULT NULL
 );
 
 CREATE TABLE comments (
-  id int generated by default as identity (start with +10000),
-  post_id int default NULL,
-  type varchar(255) default NULL,
-  body varchar(3000) default NULL
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  post_id INT DEFAULT NULL,
+  type VARCHAR(255) DEFAULT NULL,
+  body VARCHAR(3000) DEFAULT NULL
 );
 
 CREATE TABLE authors (
-  id int generated by default as identity (start with +10000),
-  name varchar(255) default NULL
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  name VARCHAR(255) DEFAULT NULL
 );
 
 CREATE TABLE tasks (
-  id int generated by default as identity (start with +10000),
-  starting timestamp default NULL,
-  ending timestamp default NULL
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  starting TIMESTAMP DEFAULT NULL,
+  ending TIMESTAMP DEFAULT NULL
 );
 
 CREATE TABLE categories (
-  id int generated by default as identity (start with +10000),
-  name varchar(255) NOT NULL,
-  type varchar(40) default NULL
+  id INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
+  name VARCHAR(255) NOT NULL,
+  type VARCHAR(40) DEFAULT NULL
 );
 
 CREATE TABLE categories_posts (
-  category_id int NOT NULL,
-  post_id int NOT NULL
+  category_id INT NOT NULL,
+  post_id INT NOT NULL
 );
 
 CREATE TABLE keyboards (
-  key_number int generated by default as identity (start with +10000),
+  key_number INT GENERATED BY DEFAULT AS IDENTITY (START WITH 10000),
   name VARCHAR(255)
 );
 
 CREATE TABLE fk_test_has_pk (
-  id INTEGER NOT NULL PRIMARY KEY
+  id INT NOT NULL PRIMARY KEY
 );
 
 CREATE TABLE fk_test_has_fk (
-  id    INTEGER NOT NULL PRIMARY KEY,
-  fk_id INTEGER NOT NULL,
+  id    INT NOT NULL PRIMARY KEY,
+  fk_id INT NOT NULL,
 
   FOREIGN KEY (fk_id) REFERENCES fk_test_has_pk(id)
 );
diff --git a/activerecord/test/fixtures/db_definitions/db22.sql b/activerecord/test/fixtures/db_definitions/db22.sql
index 9198cf5f6e..853e2c73b1 100644
--- a/activerecord/test/fixtures/db_definitions/db22.sql
+++ b/activerecord/test/fixtures/db_definitions/db22.sql
@@ -1,5 +1,5 @@
 CREATE TABLE courses (
- id int NOT NULL PRIMARY KEY,
- name varchar(255) NOT NULL
+ id INT NOT NULL PRIMARY KEY,
+ name VARCHAR(255) NOT NULL
 );