Explain filtering data and validating data
Explain filtering data and validating data - www dating forparents
For example the delivery date cannot be before the order date.Checks to ascertain that only expected characters are present in a field.
The check step uses one or more computational rules (see section below) to determine if the data is valid.A Validation rule is a criterion or constraint used in the process of data validation, carried out after the data has been encoded onto an input medium and involves a data vet or validation program.This is distinct from formal verification, where the operation of a program is determined to be that which was intended, and that meets the purpose.An e-mail address might require at least one @ sign and various other structural details.Regular expressions are effective ways of implementing such checks.The difference between data validity and accuracy can be illustrated with a trivial example.
A company has established a Personnel file and each record contains a field for the Job Grade. An entry in a record may be valid and accepted by the system if it is one of these characters, but it may not be the correct grade for the individual worker concerned.Data that does not conform to these rules will negatively affect business process execution.Therefore, data validation should start with business process definition and set of business rules within this process.These additional validity constraints may involve cross-referencing supplied data with a known look-up table or directory information service such as LDAP.For example, an experienced user may enter a well-formed string that matches the specification for a valid e-mail address, as defined in RFC 5322 but that well-formed string might not actually correspond to a resolvable domain connected to an active e-mail account.For example: Data type validation is customarily carried out on one or more simple data fields.