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_check'

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

Parameters:

  • table_name (String|Symbol) —

    Table name which constraint created on

  • condition (String) —

    Raw SQL string specifying constraint condition

  • options (Hash) —

    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 27

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

  execute <<-SQL
    ALTER TABLE #{quote_table_name(table_name)}
    ADD CONSTRAINT #{quote_column_name(name)}
    CHECK (#{condition})
  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. 



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# File 'lib/postgresql/check/schema_statements.rb', line 73

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

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

#create_table_with_checks(table_name, *args) ⇒ 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. 



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# File 'lib/postgresql/check/schema_statements.rb', line 59

def create_table_with_checks(table_name, *args)
  definition = nil

  create_table_without_checks(table_name, *args) do |td|
    definition = td # trick to get the definition
    yield td if block_given?
  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 (String|Symbol) —

    Table name which constraint defined on

  • options (Hash) —

    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 49

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

  execute <<-SQL
    ALTER TABLE #{quote_table_name(table_name)}
    DROP CONSTRAINT #{quote_column_name(name)}
  SQL
end