Let's find out a little more about this database. A `country database` contains one table, named `country`. Let's look at this table.

This table has **15 rows**. In other words, we have 15 different records for different countries.

What about columns? Here we have **7 columns**, like `id`,` name`, `continent`, `region`,
 `SurfaceArea`, `capital` and `population`.

`1. id` - the record number of this table

`2. name` - the name of the country

`3. continent` - the name of the country's continent;

`4. region`- the name of the country's  region

`5. SurfaceArea` - the surface area of the country

`6. capital` - the capital of the country

`7. population` - the population of the country.
 



We can also retrieve multiple columns with the SELECT operator. The only difference is that after the word SELECT, we will need to specify several column names, which must be **separated by a comma**. Let’s take an example where we retrieve three columns from the country table.

In this section, we will learn how to use the SQL SELECT statement to get a single table column, multiple table columns, and all table columns. We will also find out how to return unique values.

In this section, we will learn how to sort retrieved data using the ORDER BY clause. This clause, which must be the last in the SELECT statement, can be used to sort data on one or more columns as needed.\n

In this section, we will learn how to filter returned data using the SELECT statement’s WHERE clause. We will learn how to test for equality, inequality, more and less significant than value ranges, and NULL values.

In this section, we will learn how to combine WHERE clauses with the AND and OR operators. We will also find out how the NOT operator works.\n\n\n

In this section, we will learn what the SQL aggregate functions are and how to use them to summarize table data.