Class: DbSchema::Runner

Inherits:
Object
  • Object
show all
Defined in:
lib/db_schema/runner.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(changes) ⇒ Runner

Returns a new instance of Runner.



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# File 'lib/db_schema/runner.rb', line 5

def initialize(changes)
  @changes = preprocess_changes(changes)
end

Instance Attribute Details

#changes ⇒ Object (readonly)

Returns the value of attribute changes.



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# File 'lib/db_schema/runner.rb', line 3

def changes
  @changes
end

Class Method Details

.add_value_to_enum(change) ⇒ Object 



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# File 'lib/db_schema/runner.rb', line 176

def add_value_to_enum(change)
  if change.add_to_the_end?
    DbSchema.connection.add_enum_value(change.enum_name, change.new_value)
  else
    DbSchema.connection.add_enum_value(change.enum_name, change.new_value, before: change.before)
  end
end

.alter_table(change) ⇒ Object 



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# File 'lib/db_schema/runner.rb', line 92

def alter_table(change)
  DbSchema.connection.alter_table(change.name) do
    Utils.sort_by_class(
      change.fields + change.indices + change.checks,
      [
        DbSchema::Changes::DropPrimaryKey,
        DbSchema::Changes::DropCheckConstraint,
        DbSchema::Changes::DropIndex,
        DbSchema::Changes::DropColumn,
        DbSchema::Changes::RenameColumn,
        DbSchema::Changes::AlterColumnType,
        DbSchema::Changes::AllowNull,
        DbSchema::Changes::DisallowNull,
        DbSchema::Changes::AlterColumnDefault,
        DbSchema::Changes::CreateColumn,
        DbSchema::Changes::CreateIndex,
        DbSchema::Changes::CreateCheckConstraint,
        DbSchema::Changes::CreatePrimaryKey
      ]
    ).each do |element|
      case element
      when Changes::CreateColumn
        if element.primary_key?
          add_primary_key(element.name)
        else
          options = Runner.map_options(element.type, element.options)
          add_column(element.name, element.type.capitalize, options)
        end
      when Changes::DropColumn
        drop_column(element.name)
      when Changes::RenameColumn
        rename_column(element.old_name, element.new_name)
      when Changes::AlterColumnType
        attributes = Runner.map_options(element.new_type, element.new_attributes)
        set_column_type(element.name, element.new_type.capitalize, attributes)
      when Changes::CreatePrimaryKey
        raise NotImplementedError, 'Converting an existing column to primary key is currently unsupported'
      when Changes::DropPrimaryKey
        raise NotImplementedError, 'Removing a primary key while leaving the column is currently unsupported'
      when Changes::AllowNull
        set_column_allow_null(element.name)
      when Changes::DisallowNull
        set_column_not_null(element.name)
      when Changes::AlterColumnDefault
        set_column_default(element.name, element.new_default)
      when Changes::CreateIndex
        add_index(
          element.columns_to_sequel,
          name:   element.name,
          unique: element.unique?,
          type:   element.type,
          where:  element.condition
        )
      when Changes::DropIndex
        drop_index([], name: element.name)
      when Changes::CreateCheckConstraint
        add_constraint(element.name, element.condition)
      when Changes::DropCheckConstraint
        drop_constraint(element.name)
      end
    end
  end
end

.create_enum(change) ⇒ Object 



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# File 'lib/db_schema/runner.rb', line 168

def create_enum(change)
  DbSchema.connection.create_enum(change.name, change.values)
end

.create_extension(change) ⇒ Object 



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# File 'lib/db_schema/runner.rb', line 184

def create_extension(change)
  DbSchema.connection.run(%Q(CREATE EXTENSION "#{change.name}"))
end

.create_foreign_key(change) ⇒ Object 



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# File 'lib/db_schema/runner.rb', line 156

def create_foreign_key(change)
  DbSchema.connection.alter_table(change.table_name) do
    add_foreign_key(change.foreign_key.fields, change.foreign_key.table, change.foreign_key.options)
  end
end

.create_table(change) ⇒ Object 



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# File 'lib/db_schema/runner.rb', line 61

def create_table(change)
  DbSchema.connection.create_table(change.name) do
    change.fields.each do |field|
      if field.primary_key?
        primary_key(field.name)
      else
        options = Runner.map_options(field.class.type, field.options)
        column(field.name, field.type.capitalize, options)
      end
    end

    change.indices.each do |index|
      index(
        index.columns_to_sequel,
        name:   index.name,
        unique: index.unique?,
        type:   index.type,
        where:  index.condition
      )
    end

    change.checks.each do |check|
      constraint(check.name, check.condition)
    end
  end
end

.drop_enum(change) ⇒ Object 



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# File 'lib/db_schema/runner.rb', line 172

def drop_enum(change)
  DbSchema.connection.drop_enum(change.name)
end

.drop_extension(change) ⇒ Object 



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# File 'lib/db_schema/runner.rb', line 188

def drop_extension(change)
  DbSchema.connection.run(%Q(DROP EXTENSION "#{change.name}"))
end

.drop_foreign_key(change) ⇒ Object 



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# File 'lib/db_schema/runner.rb', line 162

def drop_foreign_key(change)
  DbSchema.connection.alter_table(change.table_name) do
    drop_foreign_key([], name: change.fkey_name)
  end
end

.drop_table(change) ⇒ Object 



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# File 'lib/db_schema/runner.rb', line 88

def drop_table(change)
  DbSchema.connection.drop_table(change.name)
end

.map_options(type, options) ⇒ Object 



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# File 'lib/db_schema/runner.rb', line 192

def map_options(type, options)
  mapping = case type
  when :char, :varchar, :bit, :varbit
    Utils.rename_keys(options, length: :size)
  when :numeric
    Utils.rename_keys(options) do |new_options|
      precision, scale = Utils.delete_at(new_options, :precision, :scale)

      if precision
        if scale
          new_options[:size] = [precision, scale]
        else
          new_options[:size] = precision
        end
      end
    end
  when :interval
    Utils.rename_keys(options, precision: :size) do |new_options|
      new_options[:type] = "INTERVAL #{new_options.delete(:fields).upcase}"
    end
  when :array
    Utils.rename_keys(options) do |new_options|
      new_options[:type] = "#{new_options.delete(:element_type)}[]"
    end
  else
    options
  end
end

Instance Method Details

#run! ⇒ Object 



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# File 'lib/db_schema/runner.rb', line 9

def run!
  DbSchema.connection.transaction do
    changes.each do |change|
      case change
      when Changes::CreateTable
        self.class.create_table(change)
      when Changes::DropTable
        self.class.drop_table(change)
      when Changes::AlterTable
        self.class.alter_table(change)
      when Changes::CreateForeignKey
        self.class.create_foreign_key(change)
      when Changes::DropForeignKey
        self.class.drop_foreign_key(change)
      when Changes::CreateEnum
        self.class.create_enum(change)
      when Changes::DropEnum
        self.class.drop_enum(change)
      when Changes::CreateExtension
        self.class.create_extension(change)
      when Changes::DropExtension
        self.class.drop_extension(change)
      end
    end
  end

  # Postgres doesn't allow modifying enums inside a transaction
  Utils.filter_by_class(changes, Changes::AddValueToEnum).each do |change|
    self.class.add_value_to_enum(change)
  end
end