I Learned in EWEB1

In lesson 8 I learned how to insert a row in a table. In inserting a null values you can use a two method the IMPLICIT and EXPLICIT. In Implicit method you should omit the column from the column list and the Explicit method you should specify the NULL values clause.

I also learned to copy a record from a table using a WHERE clause. And in this chapter I already know the uses of UPDATE, DELETE STATEMENT, TRUNCATE STATEMENT, COMMIT, ROLLBACK, and SAVE POINT.

In lesson 9 I learned how to use DDL statement to create and manage a table. And if your default date type is SYSDATE you will get the system date of your computer that you are using. And I learned how to delete a table permanently by using DROP statement.

In lesson10 I learned how to view a data. And I know that in this lesson that you can use view to retrieve a data.

I Learned in CTI

In our Current trends and issue subject I experienced many things and learned. I thought that collage student’s don’t have a field trip anymore. In this subject we have. We go to different companies that using new and modern technologies. Different companies using different companies.

Like in Gardenia Company they can bake a breed using latest machine. That they can bake a thousand of breed in a hour because of this machine. and now I know that the sun power is one of the leading company that supplying a solar device for our country and other country. And the pricons company are one of the leading company that are making a semi conductor.

On our seminar entitled Mobile Computing I learned the latest gadget for our phones. And also the latest cell phone that’s so very high tech. that even thou you don’t charge it will not be empty. I also know how to make a simple mobile application on our cell phones. 

ma'am thats what i've learned in Current Trends and Issue

Midterm in EWEB1

                                                Reporting Aggregated Data

                         Using the Group Functions

Lesson 4

·          I learned in this lesson how to group data from the lowest to the highest.

·         And I also know the 7 group function.

Ø  AVG

Ø  COUNT

Ø  MAX

Ø  MIN

Ø  STDDEV

Ø  SUM

Ø  VARIANCE

I learned also that:

 ü  Where clause cannot use the to restrict the instead of where you can use having clause to restrict the groups.

ü  You can use GROUP BY clause to divide rows in a table to a smaller groups.

ü  You can also use GROUP BY in multiple columns.

Displaying Data

from Multiple TablesDisplaying Data

from Multiple Tables

LESSON 5

            Lesson 5 is all about JOINS I learn in this lesson how to join table from another table using:

                         • Equijoins

                         • Nonequijoins

                         • Outer joins

                         • Self-joins

                         • Cross joins

                         • Natural joins

                          • Full (or two-sided) outer joins

Equijoins - is adding two tables with the same name.

Using - is use to match only one column when more than one column matches.

Self-join - if the two tables have the same output. Like the manager_id from employees and the employee_id from manager table you can use Self-join.

In this lesson I also know how to use Aliases.

·         Aliases is use to simplify queries.

·         You can use any characters for your queries.

·         And it also use to improve our performance

Using Subqueries to Solve Queries

Lesson 6

           

            In this lesson I learned that:

ü  What is subqueries.

ü  A subquery is a SELECT statement that is embedded in clause of another SQL Statement.

ü  I already know how to write single row and multiple row Subqueries

And I learned that this operator is use for single row comparison:

                                       1. = equal to

                                       2. > greater than

                                       3. >= greater than or equal to

                                       4. <= less than or equal to

                                       5. <> not equal

And I also learned the uses of multiple-row comparison operator:

                              1. IN  -  Equal in any member in the list

                              2. ANY  -  Compare value to each value returned by the 

                                                subquery

                              3. ALL  -  Compare value to every value returned by the 

                                                subquery