SQL

Question 1

SQL

Answer 1

Structured Query Languages

Question 2

SQL Databases

Answer 2

1. MySQL
2. Microsoft SQL Server
3. BigQuery [Google Data Cloud]

Question 3

Syntax

Answer 3

A set of guidelines unique to every programming language. This structured language includes words, symbols, and punctuation, as well as their proper placement.

Question 4

SQL Query Syntax

Answer 4

SELECT

FROM

WHERE

Question 5

SELECT

Answer 5

Use SELECT to choose the columns you want to return.

Question 6

FROM

Answer 6

Use FROM to choose the tables where the columns are located.

Question 7

WHERE

Answer 7

Use WHERE to filter for certain information.

Question 8

Query

Answer 8

A request for data or information from a database.

Question 9

Semicolon (;)

Answer 9

This is known as a statement terminator. It’s used to end a statement. Though part of the American National Standards Institute (ANSI) SQL-92’s recommended common syntax standard, it isn’t universally used or enforced by all databases.

Question 10

Comments

Answer 10

You can place comments alongside a SQL query to help you remember what the name represents. This is done using either dashes (–), /* and / or a hash symbol (#). Not all databases support the use of / and */ and the hash symbol.

Question 11

/* and */

Answer 11

Used to place a comment alongside a SQL query for name referencing. Not used by all databases.

Question 12

#

Answer 12

Used to place a comment alongside a SQL query for name referencing. Not used by all databases. [MySQL doesn’t recognise the #.]

Question 13

–

Answer 13

Used to place a comment alongside a SQL query for name referencing. Most commonly used.

Question 14

SELECT*

Answer 14

The asterick selects all of the columns in a table. Use sparingly and with caution.

Question 15

Aliases

Answer 15

You can assign a new name to a column using the AS command. An example of this would be “field1 AS last_name”. An alias doesn’t change the actual name of a column in a database.