SQL Query - Retrieve Order Dates

Overview

The provided code is a SQL query that attempts to retrieve data from a table.

Detailed Code Breakdown

• SELECT : The SQL SELECT statement is used to retrieve data from a database.

• OrderDate : This is the name of one of the columns in the table that we wish to retrieve.

• CONVERT(VARCHAR, OrderDate, 112): Here, the CONVERT() function is being used to turn the OrderDate column's data into the VARCHAR data type. The third argument, 112, is the style code which indicates the format of the date. This particular style code 112 returns the date in 'yyyymmdd' format.

• CONVERT(VARCHAR, OrderDate, 102): Again, CONVERT() function is used to convert the OrderDate data into VARCHAR data type, but with a different style code. The 102 style returns the date in 'yyyy.mm.dd' format.

• FROM Sales.SalesOrderHeader: This portion identifies the database and table from which we are selecting. Sales is the database, and SalesOrderHeader is the table within that database.

Key Concepts

The key concept to understand here is the CONVERT() function, which in SQL is used to convert data from one type to another. It takes three arguments: the data type to convert to, the data to be converted, and an optional style code which describes the format of the output.

Additional Examples

If OrderDate were a string and you wished to convert it to date format, you could use a command like CONVERT(DATE, OrderDate). You can also choose a different style code for a different output format. For example, CONVERT(VARCHAR, OrderDate, 1) would output the date in the 'mm/dd/yy' style.