Manipulation

Question 1

What does SQL stand for?

Answer 1

Structured Query Language

Question 2

What are relational databases?

Answer 2

A database that organizes info into one or more tables.

Question 3

What’s a table?

Answer 3

A collection of data values organized into rows and columns.

Question 4

What’s a column?

Answer 4

A set of data values of a particular type (id, name, age).

Question 5

What’s a row?

Answer 5

A single record in a table.

Question 6

What’s a statement?

Answer 6

Text that the database recognizes as a valid command. Statements always end in a semicolon ;

Question 7

What’s a clause?

Answer 7

Performs a specific task in SQL. Written in capital letters. Also referred to as a command. (SELECT, CREATE TABLE)

Question 8

What’s a parameter?

Answer 8

A list of columns, data types, or values that are passed to a clause as an argument.

Question 9

CREATE

Answer 9

CREATE TABLE celebs (
    id INTEGER,
    name TEXT,
    age INTEGER 
);

Question 10

INSERT

Answer 10

INSERT INTO celebs (id, name, age)

VALUES (1, ‘Justin Bieber’, 22);

Question 11

SELECT

Answer 11

SELECT name FROM celebs;

will return all data in the name column from the table

SELECT * FROM celebs;

will return every column in the table

Question 12

ALTER

Answer 12

ALTER TABLE celebs

ADD COLUMN twitter_handle TEXT;

Question 13

UPDATE

Answer 13

UPDATE celebs
SET twitter_handle = ‘@taylorswift13’
WHERE id = 4;

Question 14

DELETE

Answer 14

DELETE FROM celebs
WHERE name IS ‘Taylor Swift’;

will remove Taylor Swift from the table.

WHERE twitter_handle IS NULL;

IS NULL is a condition in SQL that returns true when the value is NULL and false otherwise.

Question 15

What are constraints?

Answer 15

Constraints that add info about how a column can be used are invoked after specifying the data type for a column.

CREATE TABLE awards (
    id INTEGER PRIMARY KEY,
    recipient TEXT NOT NULL,
    award_name TEXT DEFAULT 'Grammy'
);

Question 16

Section Review

Answer 16

SQL is a programming language designed to manipulate and manage data stored in relational databases.

Relational database is a database that organizes info into one or more tables.

Table is a collection of data organized into rows and columns.

Statement is a string of characters that the database recognizes as a valid command (CREATE TABLE, INSERT INTO, SELECT, ALTER TABLE, UPDATE, DELETE FROM).

Constraints add info about how a column can be used.