SQL Statement Syntax; AND / OR: SELECT column_name(s) FROM table_name WHERE condition AND|OR condition: ALTER TABLE: ALTER TABLE table_name ADD column_name datatype. or. ALTER TABLE table_name DROP COLUMN column_name: AS (alias) SELECT column_name AS column_alias FROM table_name. or. SELECT column_name FROM table_name AS table_alias: BETWEEN ...

This SQL keywords reference contains the reserved words in SQL. SQL Keywords. Keyword Description; ADD: Adds a column in an existing table: ADD CONSTRAINT: Adds a constraint after a table is already created: ALL: Returns true if all of …

SQL FOREIGN KEY Constraint The FOREIGN KEY constraint is used to prevent actions that would destroy links between tables. A FOREIGN KEY is a field (or collection of fields) in one table, that refers to the PRIMARY KEY in another table.

SQL References. At W3Schools you will find a complete reference for keywords and functions: SQL Keyword Reference. MYSQL Functions. SQLServer Functions. MS Access Functions. SQL Quick Reference

SQL FOREIGN KEY on ALTER TABLE. To create a FOREIGN KEY constraint on the "PersonID" column when the "Orders" table is already created, use the following SQL: MySQL / SQL Server / Oracle / MS Access:

Some of The Most Important SQL Commands. SELECT - extracts data from a database; UPDATE - updates data in a database; DELETE - deletes data from a database; INSERT INTO - inserts new data into a database; CREATE DATABASE - creates a new database; ALTER DATABASE - modifies a database; CREATE TABLE - creates a new table; ALTER TABLE - …

What is SQL? SQL stands for Structured Query Language; SQL lets you access and manipulate databases; SQL became a standard of the American National Standards Institute (ANSI) in 1986, and of the International Organization for Standardization (ISO) in 1987

At W3Schools you will find a complete reference of MySQL data types and functions: MySQL Data Types. MySQL Functions

The SQL WHERE Clause. The WHERE clause is used to filter records. It is used to extract only those records that fulfill a specified condition.

This reference contains string, numeric, date, and some advanced functions in MySQL.