| What is SQL? SQL stands for Structured Query | | | | definitions2. Query the table data3. Manipulate the |
| Language and is the lingua franca in the database | | | | table dataSQL is predominantly used by 2 types of |
| world. SQL is a standard that is used by all database | | | | users - programs and humans (keying in the |
| vendors and programmers to define, extract and | | | | commands through a database client) - to pass |
| access the information that is stored in databases. | | | | instructions to databases. SQL commands can be |
| SQL began life as an IBM creation but was | | | | keyed into a database client like the MySQL Query |
| standardized by the American National Standards | | | | Browser or the SQL Server Enterprise Manager and |
| Institute (ANSI) and the International Organization for | | | | executed to either return a result or modify records |
| Standardization (ISO) as ANSI/ISO SQL in 1988. Since | | | | in the database. SQL can also be used in conjunction |
| then ANSI/ISO SQL standard continued to evolve. | | | | with programming language or scripting language like |
| The ANSI-SQL group has since published three | | | | Microsoft Visual Basic or PHP to communicate with |
| standards over the years:1. SQL89 (SQL1)2. SQL92 | | | | the database.Although SQL is a world standard, it is |
| (SQL2)3. SQL99 (SQL3)SQL is a query language. It is | | | | unfortunate that most database vendors have come |
| English-like and easy to use. However, although there | | | | up with different dialects and variations. This is |
| are more than 90 SQL reserved words, most | | | | because every database vendor wants to |
| programmers seldom use more than the following | | | | differentiate their database products from the crowd. |
| handful of commands - SELECT, INSERT, UPDATE, | | | | One good example is Microsoft SQL Server's |
| DELETE, FROM, WHERE, HAVING, BETWEEN, LIKE, | | | | TRANSACT-SQL. TRANSACT-SQL is a superset of |
| OR, AND, NOT, IN, ORDER, GROUP and BY.For | | | | SQL and is designed for use only with Microsoft SQL |
| example, if you had a database table named | | | | Server. Although it does make programming much |
| "employees" and you wanted to retrieve all records | | | | easier for software developers, it is not compliant |
| where the employee has the last name "goodman", | | | | with other databases like Oracle or MySQL - making |
| you would use the following SQL statement:SELECT | | | | TRANSACT-SQL programs non database-portable. As |
| * FROM employees WHERE lastname = | | | | such, although many of these features are powerful |
| 'goodman';There are many different categories of | | | | and robust, it is good practice to exercise caution and |
| SQL statements but the basic ones which all | | | | limit your SQL use to be compliant with the ANSI |
| programmers should be familiar with are the SQL | | | | ISO SQL standards and ODBC-Compliant. |
| statements that:1. Create tables and manipulate their | | | | |