Module: Postgresql::Check::SchemaStatements

Extended by:
ActiveSupport::Concern
Defined in:
lib/postgresql/check/schema_statements.rb

Instance Method Summary collapse

Instance Method Details

#add_check(table_name, condition, options) ⇒ Object

Note:

:name option is mandatory.

Add a new Check constraint to table with given table_name using given conditions. Constraint name should be specified by :name options in options argument.

Examples:

add_check :products, 'price > 0', :name => 'products_price_chk'

# Generates:
# ALTER TABLE products ADD CONSTRAINT products_price_chk CHECK (price > 0)

Parameters:

  • Table name which constraint created on

  • Raw SQL string specifying constraint condition

  • Hash with single mandatory key :name

Options Hash (options):

  • :name (String|Symbol) —

    Constraint name



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# File 'lib/postgresql/check/schema_statements.rb', line 26

def add_check(table_name, condition, options)
  name = options.fetch(:name) { raise 'add_check, :name option required' }

  sql = "ALTER TABLE #{quote_table_name(table_name)} " +
      "ADD CONSTRAINT #{quote_column_name("#{table_name}_#{name}")} " +
      "CHECK (#{condition})"

  execute(sql)
end

#checks(table_name) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

API:

  • private



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# File 'lib/postgresql/check/schema_statements.rb', line 72

def checks(table_name)
  checks_info = select_all %{
    SELECT c.conname, c.consrc
    FROM pg_constraint c
    JOIN pg_class t ON c.conrelid = t.oid
    WHERE c.contype = 'c'
      AND t.relname = '#{table_name}'
  }

  checks_info.map do |row|
    Constraint.new(table_name, row['conname'], row['consrc'])
  end
end

#create_table_with_checks(table_name, *args, &block) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

API:

  • private



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# File 'lib/postgresql/check/schema_statements.rb', line 58

def create_table_with_checks(table_name, *args, &block)
  definition = nil

  create_table_without_checks(table_name, *args) do |td|
    definition = td # trick to get the definition
    block.call(td) unless block.nil?
  end

  definition.checks.each do |condition, options|
    add_check(table_name, condition, options)
  end
end

#remove_check(table_name, options) ⇒ Object

Remove constraint with given name from table. Constraint name is specified with options hash.

Examples:

remove_check :products, :name => 'products_price_chk'

# Generates:
# ALTER TABLE products DROP CONSTRAINT products_price_chk

Parameters:

  • Table name which constraint defined on

  • Hash with single mandatory key :name

Options Hash (options):

  • :name (String|Symbol) —

    Constraint name



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# File 'lib/postgresql/check/schema_statements.rb', line 48

def remove_check(table_name, options)
  name = options.fetch(:name) { raise 'remove_check, :name option required' }

  sql = "ALTER TABLE #{quote_table_name(table_name)} " +
      "DROP CONSTRAINT #{quote_column_name("#{table_name}_#{name}")}"

  execute(sql)
end