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Review of SQL
Features of SQL
• SQL is a 4th generation language.
• Non-procedural
• SQL processes several rows together rather than one row at a time. When we issue an SQL command, the command is sent to the server where all rows are dealt with at the one time.
• SQL is an ANSI standard language.
Uses of SQL
SQL is used to:
• Query data
• Insert, update, and delete rows
• Create, alter, and delete database objects
• Control access to database objects and to the database itself
• Guaranty database consistency
• Monitor database performance
SQL Command Breakdown
Commands can be divided into four categories
• Query.
• Data Manipulation Language (DML)
commands : Data Definion Language
(DDL) commands
• Security
Who uses SQL
The people who use SQL include
• User
• Developer
• Designer
• DBA
Entering SQL commands
• SQL has a buffer which stores the current command
• SQL commands can span lines
• Although not obligatory, clauses should be put on separate lines to improve
readablity.
Approximate Word count = 764
Approximate Pages = 3.1
(250 words per page double spaced)
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