Some data quality components enable you to check data in databases against regular expressions, for example tMultiPatternCheck, tPatternCheck, tMySQLInvalidRows, tMySQLValidRows and other similar components.
Some data quality components enable you to group similar data according to matching rules. An example component is tMatchGroupHadoop.
Some data quality components enable you to check data in databases against reference data sources. An example component is tSchemaComplianceCheck component.
For further information and example Jobs about the validation components, see the data quality chapter in the Talend Components Reference Guide.
The data quality demo project has also ready-to-use Jobs that may use validation components. For further information, see Importing a data quality demo project.