. Explain table relations? Explain the purpose with an example?

3 relations:
      a. Normal: Represents one column value related to a column in another  table.

      b. Field fixed: This relation is used when one column field in a table can relate to several columns in another tables. Means based on a specific value of one field another field value changes.
      Example: If we have a table called Parent, which contains two fields named Check (Enum 0 or 1), Name. If there is a situation where based on the Check column value the value or drop down for Name should differ. Here if Check column is marked than Name should get the drop down list from the EmplTable and if Check is not marked than it should be from CustTable. 

4. Related field fixed: This relation is used to restrict the records retrieved (shown in lookup) from the related table by applying some constraint to it.

      Example: In a table field called Name if we want to lookup only the employees whose status is checked than we must have to use this relation.

Here’s the depiction which shows the above scenario