Questions

A Project is a temporary endeavour undertaken to create a unique product, service or result.

Characteristics:

1.Temporary 

    Temporary means that every project has a definite beginning and a definite end.

2. Unique Products, Services or Results

   Uniqueness is an important characteristic of project deliverables. For example, many thousands of office buildings have been developed, but each individual facility is unique - different owner, different design, different location, different contractors, and so on.

3. Progressive Elaboration

   Progressive elaboration means developing in steps, and continuing by increments . For example, the project scope will be broadly described early in the project and made more explicit and detailed as the project team develops a better and more complete understanding of the objectives and deliverables.

A Subquery or Inner query or a Nested query is a query within another SQL query and embedded within the WHERE clause.

Subqueries are most frequently used with the SELECT statement. The basic syntax is as follows::

SELECT column_name [, column_name ]
FROM table1 [, table2 ]
WHERE column_name OPERATOR
(SELECT column_name [, column_name ]
FROM table1 [, table2 ]
[WHERE])

A subquery is used to return data that will be used in the main query as a condition to further restrict the data to be retrieved.

Subqueries can be used with the SELECT, INSERT, UPDATE, and DELETE statements along with the operators like =, <, >, >=, <=, IN, BETWEEN, etc.

There are a few rules that subqueries must follow −

1. Subqueries must be enclosed within parentheses.

2. A subquery can have only one column in the SELECT clause, unless multiple columns are in the main query for the subquery to compare its selected columns.

3. An ORDER BY command cannot be used in a subquery, although the main query can use an ORDER BY. The GROUP BY command can be used to perform the same function as the ORDER BY in a subquery.

4. Subqueries that return more than one row can only be used with multiple value operators such as the IN operator.

5. The SELECT list cannot include any references to values that evaluate to a BLOB, ARRAY, CLOB, or NCLOB.

6. A subquery cannot be immediately enclosed in a set function.

7. The BETWEEN operator cannot be used with a subquery. However, the BETWEEN operator can be used within the subquery.

TRUTH TABLE FOR HALF ADDER

A    B  SUM  CARRY

0    0    0         0

0    1    1         0

1    0    1         0

1    1    0         1

INPLEMENTATION:

For SUM, The two inputs A and B are given to XOR gate.

For Carry, The two inputs A and B are given to AND gate.

The chemical composition of a rock is mainly minerals.