from DataTypes import *
# Bundles together functions for probing a MySQL database to confirm
# whether or not it adheres to specific properties of a logical/relational schema.
# Can be used to verify that a MySQL database correctly implements a design.
class DataModelChecker:
# Ctor sets the connection details for this model checker
def __init__( self, host, username, password, database ):
# TODO: Implement me!
# Predicate function that connects to the database and confirms
# whether or not a list of attributes is set up as a (super)key for a given table
# For example, if attributes contains table_name R and attributes [x, y],
# this function returns true if (x,y) is enforced as a key in R
# @see Util.Attributes
# @pre the tables and attributes in attributes must already exist
def confirmSuperkey( self, attributes ):
# TODO: Implement me!
return true
# Predicate function that connects to the database and confirms
# whether or not `referencing_attributes` is set up as a foreign
# key that reference `referenced_attributes`
# For example, if referencing_attributes contains table_name R and attributes [x, y]
# and referenced_attributes contains table_name S and attributes [a, b]
# this function returns true if (x,y) is enforced as a foreign key that references
# (a,b) in R
# @see Util.Attributes
# @pre the tables and attributes in referencing_attributes and referenced_attributes must already exist
def confirmForeignKey( self, referencing_attributes, referenced_attributes ):
# TODO: Implement me!
return true
# Predicate function that connects to the database and confirms
# whether or not `referencing_attributes` is set up as a foreign key
# that reference `referenced_attributes` using a specific referential integrity `policy`
# For example, if referencing_attributes contains table_name R and attributes [x, y]
# and referenced_attributes contains table_name S and attributes [a, b]
# this function returns true if (x,y) the provided policy is used to manage that foreign key
# @see Util.Attributes, Util.RefIntegrityPolicy
# @pre The foreign key is valid
# @pre policy must be a valid Util.RefIntegrityPolicy
def confirmReferentialIntegrity( self, referencing_attributes, referenced_attributes, policy ):
# TODO: Implement me!
return true
# Predicate function that connects to the database and confirms
# whether or not `referencing_attributes` is set up in such as way as to
# functionally determine `referenced_attributes`
# For example, if referencing_attributes contains table_name R and attributes [x, y]
# and referenced_attributes contains table_name S and attributes [a, b]
# this function returns true if (x,y) is enforced to functionally determine (a,b) in R
# @see Util.Attributes
# @pre the tables and attributes in referencing_attributes and referenced_attributes must already exist
def confirmFunctionalDependency( self, referencing_attributes, referenced_attributes ):
# TODO: Implement me!
return true
# Predicate function that connects to the database and confirms
# whether or not any tuples in a given table are permitted to violate
# a constraint expressed as a SQL snippet.
# For example, given `R` and `x >= 0`, this function would return
# true if it is not possible to add tuples to `R` with negative `x` values.
# @pre sql_predicate must be valid SQL syntax that can be used as is in a WHERE condition
# @pre table_name must exist in the database already
def confirmArbitraryConstraint( self, table_name, sql_predicate ):
# TODO: Implement me!
return true