DDD - Implementation

Question 1

How are tables linked in a relational database

Answer 1

tables are linked by matching the foreign key from one table to the primary key in a related table

Question 2

what does referential integrity mean

Answer 2

that all of the foreign keys in a table must link to a primary key in a related table

Question 3

What does the SELECT statement

Answer 3

selects data from a database

Question 4

what does the asterisk symbol do

Answer 4

select all of the fields in the table

Question 5

The FROM command is used to

Answer 5

specify which tables to select data from

Question 6

what does the order by statement

Answer 6

sorts the results of an SQL query in ascending or descending order

Question 7

what is ascending order

Answer 7

A-Z, 1-10

Question 8

what is descending order

Answer 8

Z-A, 10-1

Question 9

<

Answer 9

less than

Question 10

>

Answer 10

greater than

Question 11

=

Answer 11

equal

Question 12

when will <,>, = operators can be used

Answer 12

within the WHERE clause to refine SQL queries

Question 13

When can the OR and AND operators can be used

Answer 13

with the WHERE clause to refine SQL queries

Question 14

what is the INSERT INTO statement used for

Answer 14

to insert a record into a table

Question 15

syntax for insert

Answer 15

INSERT INTO table
VALUES (values to be inserted);

Question 16

what is the UPDATE staement used for

Answer 16

to update a record in atable

Question 17

syntax for update

Answer 17

UPDATE table
SET column = value
WHERE criteria;

Question 18

What is the DELETE statement used for

Answer 18

to delete a record from a table

Question 19

syntax for delete

Answer 19

DELETE FROM table
WHERE criteria;

Question 20

what is an equi-join

Answer 20

used to join matching columns of related tables

Question 21

syntax for equi-joins

Answer 21

SELECT fields
FROM table_1, table_2
WHERE table_1.column_name= table_2.column_name