SQL Tutorial

Question 1

SQL stands for…

Answer 1

Structured Query Language

Question 2

SQL lets you…

Answer 2

access and manipulate databases

Question 3

What can SQL do? (1)

Answer 3

SQL can execute queries against a database

Question 4

What can SQL do? (2)

Answer 4

SQL can retrieve data from a database

Question 5

What can SQL do? (3)

Answer 5

SQL can insert records in a database

Question 6

What can SQL do? (4)

Answer 6

SQL can update records in a database

Question 7

What can SQL do? (5)

Answer 7

SQL can delete records from a database

Question 8

What can SQL do? (6)

Answer 8

SQL can create new databases

Question 9

What can SQL do? (7)

Answer 9

SQL can create new tables in a database

Question 10

What can SQL do? (8)

Answer 10

SQL can create stored procedures in a database

Question 11

What can SQL do? (9)

Answer 11

SQL can create views in a database

Question 12

What can SQL do? (10)

Answer 12

SQL can set permissions on tables, procedures, and views

Question 13

RDBMS stands for…

Answer 13

Relational Database Management System

Question 14

RDBMS is…

Answer 14

the basis for SQL, and for all modern database systems such as MS SQL Server, IBM, DB2, Oracle, MySQL, and Microsoft Access

Question 15

The data in RDBMS is stored in…

Answer 15

database objects called tables

Question 16

A table is…

Answer 16

a collection of related data entries and it consists of columns and rows

Question 17

Every table is broken up into…

Answer 17

smaller entities called fields

Question 18

A field is…

Answer 18

a column in a table that is designed to maintain specific information about every record in the table

Question 19

A record, also called a row, is…

Answer 19

each individual entry that exists in a table

Question 20

A record is…

Answer 20

a horizontal entity in a table

Question 21

A column is…

Answer 21

a vertical entity in a table that contains all information associated with a specific field in a table

Question 22

SQL Command: SELECT

Answer 22

extracts data from a database

Question 23

SQL Command: UPDATE

Answer 23

updates data in a data base

Question 24

SQL Command: DELETE

Answer 24

deletes data from a database

Question 25

SQL Command: INSERT INTO

Answer 25

inserts new data into a database

Question 26

SQL Command: CREATE DATABASE

Answer 26

creates a new database

Question 27

SQL Command: ALTER DATABASE

Answer 27

modifies a database

Question 28

SQL Command: CREATE TABLE

Answer 28

creates a new table

Question 29

SQL Command: ALTER TABLE

Answer 29

modifies a table

Question 30

SQL Command: DROP TABLE

Answer 30

deletes a table

Question 31

SQL Command: CREATE INDEX

Answer 31

creates an index (search key)

Question 32

SQL Command: DROP INDEX

Answer 32

deletes an index

Question 33

Semicolon after SQL Statements

Answer 33

Semicolon is the standard way to separate each SQL statement in database systems that allow more than one SQL statement to be executed in the same call to the server

Question 34

The SQL SELECT Statement

Answer 34

The SELECT statement is used to select data from a database. The data returned is store in a result table, called the result-set

Question 35

SELECT column1, column2, …
FROM table_name;

Answer 35

SELECT Syntax

Question 36

If you want to select all the fields available in the table…

Answer 36

SELECT * FROM table_name;

Question 37

The SQL SELECT DISTINCT Statement

Answer 37

The SELECT DISTINCT statement is used to return only distinct (different) values

Question 38

SELECT DISTINCT column1, column2, …
FROM table_name;

Answer 38

SELECT DISTINCT Syntax

Question 39

The SQL WHERE Clause

Answer 39

The WHERE clause is used to filter records

Question 40

SELECT column1, column2, …
FROM table_name
WHERE condition;

Answer 40

WHERE Syntax

Question 41

SELECT COUN(DISTINCT column) FROM table_name;

Answer 41

This stastement lists the number of different (distinct) customer countries (is not supported in Microsoft Access)

Question 42

Text Fields vs. Numeric Fields

Answer 42

SQL requires single quotes around text values (most database systems will also allow double quotes)
However, numeric fields shoud not be enclosed in quotes

Question 43

Operators in The WHERE Clause (1)

Answer 43

Equal

Question 44

Operators in The WHERE Clause (2)
>

Answer 44

Greater than

Question 45

Operators in The WHERE Clause (3)
<

Answer 45

Less than

Question 46

Operators in The WHERE Clause (4)
>=

Answer 46

Greater than or equal

Question 47

Operators in The WHERE Clause (5)
<=

Answer 47

Less than or equal

Question 48

Operators in The WHERE Clause (6)
<>

Answer 48

Not equal
Note: In some versions of SQL this operator may be written as !=

Question 49

Operators in The WHERE Clause (7)
BETWEEN

Answer 49

Between a certain range

Question 50

Operators in The WHERE Clause (8)
LIKE

Answer 50

Search for a pattern

Question 51

Operators in The WHERE Clause (9)
IN

Answer 51

To specify multiple possible values for a column

Question 52

The SQL AND Operator

Answer 52

The AND operator are used to filter records based on:
The AND operator displays a record if all the conditions separated by AND are TRUE

Question 53

The SQL OR Operator

Answer 53

The OR operator are used to filter records based on:
The OR operator displays a record if any of the conditions separated by OR is TRUE

Question 54

The SQL NOT Operator

Answer 54

The NOT operator displays a record if the condition(s) is NOT TRUE

Question 55

SELECT column1, column2, …
FROM table_name
WHERE condition1 AND condition2 AND condition3 …;

Answer 55

AND Syntax

Question 56

SELECT column1, column2, …
FROM table_name
WHERE condition1 OR condition2 OR condition3 …;

Answer 56

OR Syntax

Question 57

SELECT column1, column2, …
FROM table_name
WHERE NOT condition;

Answer 57

NOT Syntax

Question 58

Combining AND, OR and NOT

Answer 58

You can also combine the AND, OR and NOT operators