Technical Interview Questions and Answers :: Wipro

A FOREIGN KEY is one or more columns whose values are based on the PRIMARY or CANDITATE KEY values from the database.

No Discussion on this question yet!

No Discussion on this question yet!

No Discussion on this question yet!

Yes, Consider a category table in a e-commerce web site.
Category_Id, Category_Name, Parent_Category_ID. In this table all the parent categories are also categories. When we create a self join category id will be treated as foreign key to the same table.

The UNIQUE KEY column restricts entry of duplicate values but entry of NULL value is allowed. In case of PRIMARY KEY columns entry of duplicate as well as value is also restricted.

No Discussion on this question yet!

The join type that you specify for a join condition determines whether the Integration Server needs to receive all, any, or only one of the documents to execute the trigger service. The following table describes the join types that you can specify for a condition.

Join Type Description

All (AND) The Integration Server invokes the associated trigger service when the server receives an instance of each specified publishable document type within the join time-out period. The instance documents must have the same activation ID. This is the default join type.For example, suppose that a join condition specifies document types A and B and C. Instances of all the document types must be received to satisfy the join condition. Additionally, all documents must have the same activation ID and must be received before the specified join time-out elapses.

Any (OR) The Integration Server invokes the associated trigger service when it receives an instance of any one of the specified publishable document types.

For example, suppose that the join condition specifies document types A or B or C. Only one of these documents is required to satisfy the join condition. The Integration Server invokes the associated trigger service every time it receives a document of type A, B, or C. The activation ID does not matter. No time-out is

necessary.

Only one (XOR) The Integration Server invokes the associated trigger service when it receives an instance of any of the specified document types. For the duration of the join time-out period, the Integration Server discards (blocks) any instances of the specified publishable document types with the same activation ID. For example, suppose that the join condition specifies document types A or B or C. Only one of these documents is required to satisfy the join condition. It does not matter which one. The Integration Server invokes the associated trigger service after it receives an instance of one of the specified document types. The integration Server continues to discard instances of any qualified document types with the same activation ID until the specified join time-out elapses.

Join conditions are conditions that associate two or more document types with a single trigger service. Typically, join conditions are used to combine data published by different sources and process it with one service.

No Discussion on this question yet!