Class: Mgt::ActiveRecord

Inherits:
Object show all
Defined in:
lib/orm/active_record.rb,
lib/orm/query_generator.rb

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.all ⇒ Object 



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# File 'lib/orm/query_generator.rb', line 11

def self.all
  data = Database.execute "SELECT #{attributes_keys.join(',')}
  FROM #{@table} ORDER BY id DESC"
  data.map do |row|
    map_object(row)
  end
end

.attribute(column_name, args) ⇒ Object 



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# File 'lib/orm/active_record.rb', line 13

def self.attribute(column_name, args)
  @attributes ||= {}
  @attributes[column_name] = args
end

.attributes_keys ⇒ Object 



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# File 'lib/orm/active_record.rb', line 51

def self.attributes_keys
  @attributes.keys
end

.create_table ⇒ Object 



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# File 'lib/orm/active_record.rb', line 18

def self.create_table
  all_attributes = []
  @attributes.each do |key, value|
    attributes ||= []
    attributes << key.to_s
    value.each do |name, type|
      attributes << send("#{name.downcase}_query", type)
    end
    all_attributes << attributes.join(" ")
  end
  query = "CREATE TABLE
  IF NOT EXISTS #{@table} (#{all_attributes.join(', ')})"
  Database.execute(query)
  make_methods
end

.destroy(id) ⇒ Object 



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# File 'lib/orm/query_generator.rb', line 45

def self.destroy(id)
  Database.execute "DELETE FROM #{table_name} WHERE id = ?", id
end

.destroy_all ⇒ Object 



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# File 'lib/orm/query_generator.rb', line 71

def self.destroy_all
  Database.execute "DELETE FROM #{@table}"
end

.find(id) ⇒ Object 



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# File 'lib/orm/query_generator.rb', line 39

def self.find(id)
  row = Database.execute("SELECT #{attributes_keys.join(',')}
  FROM #{@table} WHERE id = ?", id).first
  map_object(row)
end

.find_by(finder) ⇒ Object 



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# File 'lib/orm/query_generator.rb', line 3

def self.find_by(finder)
  key = finder.keys[0].to_s
  value = finder.values[0].to_s
  row = Database.execute("SELECT #{attributes_keys.join(',')}
  FROM #{@table} WHERE #{key} = ?", value).first
  map_object(row)
end

.first ⇒ Object 



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# File 'lib/orm/query_generator.rb', line 33

def self.first
  query = "SELECT * FROM #{@table} ORDER BY id LIMIT 1"
  row = (Database.execute query).first
  map_object(row)
end

.last ⇒ Object 



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# File 'lib/orm/query_generator.rb', line 27

def self.last
  query = "SELECT * FROM #{@table} ORDER BY id DESC LIMIT 1"
  row = (Database.execute query).first
  map_object(row)
end

.make_methods ⇒ Object 



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# File 'lib/orm/active_record.rb', line 34

def self.make_methods
  mtds = @attributes.keys.map(&:to_sym)
  mtds.each { |mtd| attr_accessor mtd }
end

.map_object(row) ⇒ Object 



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# File 'lib/orm/active_record.rb', line 55

def self.map_object(row)
  model_name = new
  @attributes.each_key.with_index do |value, index|
    model_name.send("#{value}=", row[index])
  end
  model_name
end

.nullable_query(value = true) ⇒ Object 



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# File 'lib/orm/active_record.rb', line 43

def self.nullable_query(value = true)
  "NOT NULL" unless value
end

.primary_key_query(value = false) ⇒ Object 



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# File 'lib/orm/active_record.rb', line 39

def self.primary_key_query(value = false)
  "PRIMARY KEY AUTOINCREMENT" if value
end

.table(table_name) ⇒ Object 



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# File 'lib/orm/active_record.rb', line 5

def self.table(table_name)
  @table = table_name
end

.table_name ⇒ Object 



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# File 'lib/orm/active_record.rb', line 9

def self.table_name
  @table
end

.type_query(value) ⇒ Object 



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# File 'lib/orm/active_record.rb', line 47

def self.type_query(value)
  value.to_s
end

.where(query_pattern, value) ⇒ Object 



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# File 'lib/orm/query_generator.rb', line 19

def self.where(query_pattern, value)
  data = Database.execute "SELECT #{attributes_keys.join(',')} FROM
  #{@table} WHERE #{query_pattern}", value
  data.map do |row|
    map_object(row)
  end
end

Instance Method Details

#destroy ⇒ Object 



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# File 'lib/orm/query_generator.rb', line 66

def destroy
  table_name = self.class.table_name
  Database.execute "DELETE FROM #{table_name} WHERE id = ?", id
end

#get_columns ⇒ Object 



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# File 'lib/orm/active_record.rb', line 63

def get_columns
  columns = self.class.attributes_keys
  columns.delete(:id)
  columns.join(",")
end

#get_values ⇒ Object 



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# File 'lib/orm/active_record.rb', line 69

def get_values
  attributes = self.class.attributes_keys
  attributes.delete(:id)
  attributes.map { |method| send(method) }
end

#new_record_placeholders ⇒ Object 



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# File 'lib/orm/active_record.rb', line 87

def new_record_placeholders
  attributes = self.class.attributes_keys
  (["?"] * (attributes.size - 1)).join(",")
end

#new_record_value ⇒ Object 



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# File 'lib/orm/active_record.rb', line 75

def new_record_value
  get_values
end

#save ⇒ Object 



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# File 'lib/orm/query_generator.rb', line 49

def save
  table_name = self.class.table_name
  if id
    Database.execute "UPDATE #{table_name} SET
    #{update_records_placeholders} WHERE id = ?", update_records
  else
    Database.execute "INSERT INTO #{table_name} (#{get_columns})
    VALUES  (#{new_record_placeholders})", new_record_value
  end
end

#update(params) ⇒ Object 



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# File 'lib/orm/query_generator.rb', line 60

def update(params)
  table_name = self.class.table_name
  Database.execute "UPDATE #{table_name} SET
  #{update_values_placeholders(params)} WHERE id=?", update_values(params)
end

#update_records ⇒ Object 



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# File 'lib/orm/active_record.rb', line 79

def update_records
  get_values << send(:id)
end

#update_records_placeholders ⇒ Object 



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# File 'lib/orm/active_record.rb', line 98

def update_records_placeholders
  columns = self.class.attributes_keys
  columns.delete(:id)
  columns.map { |col| "#{col}=?" }.join(",")
end

#update_values(params) ⇒ Object 



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# File 'lib/orm/active_record.rb', line 83

def update_values(params)
  params.values << id
end

#update_values_placeholders(params) ⇒ Object 



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# File 'lib/orm/active_record.rb', line 92

def update_values_placeholders(params)
  columns = params.keys
  columns.delete(:id)
  columns.map { |col| "#{col}=?" }.join(",")
end