SQL ORDER BY statement: sorting

In SQL, the ORDER BY keyword is used to sort the result-set in ascending or descending order. It sorts the records in a result set by one or more columns.

The ORDER BY keyword sorts the records in ascending order by default. If you want to sort the records in a descending order, you can use the DESC keyword.

Here's the basic syntax:

SELECT column1, column2, ...
FROM table_name
ORDER BY column1 [ASC|DESC], column2 [ASC|DESC], ...;

Examples:

Consider the following Employees table:

EmployeeID	FirstName	LastName
1	John	Doe
2	Jane	Smith
3	Alice	Johnson
4	Charlie	Brown
5	David	Thompson

Order by ascending FirstName:

SELECT * FROM Employees
ORDER BY FirstName ASC;

This SQL statement selects all data from the "Employees" table, sorted in ascending order by the "FirstName" column.

Order by descending LastName:

SELECT * FROM Employees
ORDER BY LastName DESC;

This SQL statement selects all data from the "Employees" table, sorted in descending order by the "LastName" column.

Order by multiple columns:

SELECT * FROM Employees
ORDER BY FirstName ASC, LastName DESC;

This SQL statement selects all data from the "Employees" table, sorted in ascending order by the "FirstName" and then in descending order by the "LastName".

Note:

If the ORDER BY clause is not specified, the order of the rows in the result-set is undefined.
Always place the ORDER BY clause at the end of your SQL statement.
As always, the exact syntax may vary between different SQL dialects, so be sure to consult the documentation for the SQL dialect you're using.

How to Use ORDER BY in SQL:
- Description: The ORDER BY clause is used to sort the result set in ascending (default) or descending order based on one or more columns.
- Code Example:
```
SELECT column1, column2
FROM example_table
ORDER BY column1;
```
SQL ORDER BY Ascending and Descending:
- Description: You can specify the sorting order with ASC (ascending) or DESC (descending) in the ORDER BY clause.
- Code Example:
```
SELECT column1, column2
FROM example_table
ORDER BY column1 DESC;
```
Sorting Multiple Columns in SQL ORDER BY:
- Description: You can sort by multiple columns by specifying their order in the ORDER BY clause.
- Code Example:
```
SELECT column1, column2, column3
FROM example_table
ORDER BY column1 ASC, column2 DESC;
```
ORDER BY with NULL Values in SQL:
- Description: By default, NULL values are sorted first in ascending order. Use NULLS LAST to sort them last.
- Code Example:
```
SELECT column1, column2
FROM example_table
ORDER BY column1 NULLS LAST;
```
SQL ORDER BY String and Numeric Sorting:
- Description: SQL automatically sorts strings and numbers appropriately. Ensure the data types match for correct sorting.
- Code Example:
```
SELECT column1, column2
FROM example_table
ORDER BY column1, column2;
```
Custom Sorting in SQL ORDER BY:
- Description: Use a CASE statement in the ORDER BY clause for custom sorting logic.
- Code Example:
```
SELECT column1, column2
FROM example_table
ORDER BY CASE WHEN column1 = 'CustomValue' THEN 0 ELSE 1 END, column2;
```
Sorting by Date in SQL ORDER BY:
- Description: Dates can be sorted using ORDER BY just like other data types.
- Code Example:
```
SELECT column1, column2, date_column
FROM example_table
ORDER BY date_column DESC;
```
Limiting Rows with TOP and ORDER BY in SQL:
- Description: Use TOP (SQL Server) or LIMIT (for other databases) with ORDER BY to limit the number of rows returned.
- Code Example:
```
SELECT TOP 5 column1, column2
FROM example_table
ORDER BY column1 DESC;
```
Sorting Results of JOIN in SQL:
- Description: When joining tables, use ORDER BY to sort the combined result set based on columns from any joined table.
- Code Example:
```
SELECT table1.column1, table2.column2
FROM table1
INNER JOIN table2 ON table1.id = table2.id
ORDER BY table1.column1 ASC, table2.column2 DESC;
```