SQL Syntax

What does a SQL statement look like?

SQL statements are somewhat like simple English sentences.
Keywords include SELECT, UPDATE, WHERE, ORDER BY, etc.

ANSI Standard SQL is the lingua franca for relational databases.
By the way, the syntax of a language describes the language elements.

The SQL Syntax

SQL was designed to be entered on a console and results would display back to a screen. Today, SQL is mostly used by programmers who use SQL inside their language to build applications that access data in a database.

Four fundamental operations that apply to any database are:

SELECT -- Read the data
INSERT -- Insert new data
UPDATE -- Update existing data
DELETE -- Remove data

Collectively these are referred to as CRUD (Create, Read, Update, Delete).

The general form for each of these 4 operations in SQL is presented next.

The SQL SELECT general form

SELECT column-names
  FROM table-name
 WHERE condition
 ORDER BY sort-order

SELECT FirstName, LastName, City, Country 
  FROM Customer
 WHERE City = 'Paris'
 ORDER BY LastName

The SQL INSERT general form

INSERT table-name (column-names)
VALUES (column-values)

INSERT Supplier (Name, ContactName, City, Country)
VALUES ('Oxford Trading', 'Ian Smith', 'Oxford', 'UK')

The SQL UPDATE general form

UPDATE table-name
   SET column-name = column-value
 WHERE condition

UPDATE OrderItem
   SET Quantity = 2
 WHERE Id = 388

The SQL DELETE general form

DELETE table-name
 WHERE condition

DELETE Customer
 WHERE Email = 'alex@gmail.com'