Module: Sequel::ConstraintValidations

Defined in:
lib/sequel/extensions/constraint_validations.rb

Defined Under Namespace

Modules: AlterTableGeneratorMethods, CreateTableGeneratorMethods Classes: Generator

Constant Summary collapse

DEFAULT_CONSTRAINT_VALIDATIONS_TABLE =

The default table name used for the validation metadata.

:sequel_constraint_validations

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#constraint_validations_table ⇒ Object

The name of the table storing the validation metadata. If modifying this from the default, this should be changed directly after loading the extension into the database



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# File 'lib/sequel/extensions/constraint_validations.rb', line 211

def constraint_validations_table
  @constraint_validations_table
end

Class Method Details

.extended(db) ⇒ Object

Set the default validation metadata table name if it has not already been set.



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# File 'lib/sequel/extensions/constraint_validations.rb', line 133

def self.extended(db)
  db.constraint_validations_table ||= DEFAULT_CONSTRAINT_VALIDATIONS_TABLE
end

Instance Method Details

#alter_table_generator(&block) ⇒ Object

Modify the default alter_table generator to include the constraint validation methods.



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# File 'lib/sequel/extensions/constraint_validations.rb', line 277

def alter_table_generator(&block)
  super do
    extend AlterTableGeneratorMethods
    @validations = []
    instance_eval(&block) if block
  end
end

#create_constraint_validations_table ⇒ Object

Create the table storing the validation metadata for all of the constraints created by this extension.



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# File 'lib/sequel/extensions/constraint_validations.rb', line 215

def create_constraint_validations_table
  create_table(constraint_validations_table) do
    String :table, :null=>false
    String :constraint_name
    String :validation_type, :null=>false
    String :column, :null=>false
    String :argument
    String :message
    TrueClass :allow_nil
  end
end

#create_table_generator(&block) ⇒ Object

Modify the default create_table generator to include the constraint validation methods.



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# File 'lib/sequel/extensions/constraint_validations.rb', line 229

def create_table_generator(&block)
  super do
    extend CreateTableGeneratorMethods
    @validations = []
    instance_eval(&block) if block
  end
end

#drop_constraint_validations_for(opts = OPTS) ⇒ Object

Delete validation metadata for specific constraints. At least one of the following options should be specified:

:table

The table containing the constraint

:column

The column affected by the constraint

:constraint

The name of the related constraint

The main reason for this method is when dropping tables or columns. If you have previously defined a constraint validation on the table or column, you should delete the related metadata when dropping the table or column. For a table, this isn’t a big issue, as it will just result in some wasted space, but for columns, if you don’t drop the related metadata, it could make it impossible to save rows, since a validation for a nonexistent column will be created.



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# File 'lib/sequel/extensions/constraint_validations.rb', line 258

def drop_constraint_validations_for(opts=OPTS)
  ds = from(constraint_validations_table)
  if table = opts[:table]
    ds = ds.where(:table=>constraint_validations_literal_table(table))
  end
  if column = opts[:column]
    ds = ds.where(:column=>column.to_s)
  end
  if constraint = opts[:constraint]
    ds = ds.where(:constraint_name=>constraint.to_s)
  end
  unless table || column || constraint
    raise Error, "must specify :table, :column, or :constraint when dropping constraint validations"
  end
  ds.delete
end

#drop_constraint_validations_table ⇒ Object

Drop the constraint validations table.



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# File 'lib/sequel/extensions/constraint_validations.rb', line 238

def drop_constraint_validations_table
  drop_table(constraint_validations_table)
end