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_tableObject

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


211
212
213
# 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.


133
134
135
# 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.


277
278
279
280
281
282
283
# 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_tableObject

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


215
216
217
218
219
220
221
222
223
224
225
# 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.


229
230
231
232
233
234
235
# 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.


258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
# 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_tableObject

Drop the constraint validations table.


238
239
240
# File 'lib/sequel/extensions/constraint_validations.rb', line 238

def drop_constraint_validations_table
  drop_table(constraint_validations_table)
end