![Coding One command may extend across several lines [Enter] doesn’t represent the end of a statement SQL uses ; (semi-colon) to identify statement end ; is optional in SQL Server Keywords are capitalized CREATE DATABASE MyNewDatabase No standard conventions for naming Typically use Pascal case naming with each new word capitalized](https://image.slidesharecdn.com/3sqloverview-100408102724-phpapp01/85/Sql-Overview-8-320.jpg)
![Coding Reference SQL Server uses special characters to identify different parts of commands End of statement: ; Optional in SQL Server Placeholder: <> Placeholder Definition: ::= Optional Parameter(s): [ ] Specific Parameter Values: { } Value Separator: | List Separator: ,](https://image.slidesharecdn.com/3sqloverview-100408102724-phpapp01/85/Sql-Overview-11-320.jpg)
Sql Overview
- 2. Structured Query Language Language used to work with databases Used in ‘back end’ Typically not part of user interface (don’t expect users to type in a query…)
- 3. SEQEL to SQL Structured English Query Language developed by IBM Other companies developed similar products ANSI set standards in 1986 Standards are ‘open’ Different vendors have different levels of conformance
- 4. SQL Most languages are procedural Describe how to perform a task SQL is non-procedural (declarative) Code describes results Includes some procedural components If … Then, Loops Database apps typically use both types of languages Procedural languages manage interface, data requests SQL manages data storage and retrieval
- 5. Types of SQL Statements Data Definition Language (DDL): Create/edit objects CREATE, ALTER Data Control Language (DCL): Specify access and permissions GRANT, REVOKE Data Manipulation Language (DML): Work with data SELECT * FROM Employees INSERT INTO Students
- 6. Logical Organization Catalogs: group of schemas Schema: group of related tables, views Implementation is up to vendor Some vendors use catalogs, some don’t Vendors have different levels of support for schemas
- 7. Databases ‘ Database’ is not an ANSI specification Most vendors have a database object In practice, schema and database tend to be viewed interchangeably Schema defines the contents of a database May have sub-schemas to reflect application needs (include only a portion of the database)
- 8. Coding One command may extend across several lines [Enter] doesn’t represent the end of a statement SQL uses ; (semi-colon) to identify statement end ; is optional in SQL Server Keywords are capitalized CREATE DATABASE MyNewDatabase No standard conventions for naming Typically use Pascal case naming with each new word capitalized
- 9. Naming Requirements Object names are not typically case sensitive Delimited identifiers wrap names in double quotes and ARE case sensitive “ MyNewTable” uses double quotes to identify the object name Single quotes identify strings (text) Can use letters, numbers, underscore Can’t use spaces, punctuation
- 10. Qualified Names A qualified name defines explicitly how to find an object ‘ .’ is used as separator SQL Server uses ServerName.DatabaseName.OwnerName.ObjectName OR ServerName.DatabaseName.SchemaName.ObjectName
- 11. Coding Reference SQL Server uses special characters to identify different parts of commands End of statement: ; Optional in SQL Server Placeholder: <> Placeholder Definition: ::= Optional Parameter(s): [ ] Specific Parameter Values: { } Value Separator: | List Separator: ,
- 12. Placeholder Example Basic command definition: ON UPDATE <referential action> <referential action> ::= CASCADE|SET NULL <referential action> is placeholder CASCADE|SET NULL is placeholder definition (placeholder value must be one of these choices)
- 13. Management Studio Microsoft GUI for most SQL Server operations Additional applications manage overall server security, business intelligence Separate application from SQL Server Uses a connection to send commands and capture results SQL Server is not something we’ll work with directly
Editor's Notes
- #3: 04/08/10 CIS-182 SQL