Google Links

Follow the links below to find material targeted to the unit's elements, performance criteria, required skills and knowledge

Elements and Performance Criteria

1. Select data-access layer (DAL)
   • Review function of DAL in multi-layer application model
   • Determine data-access application programming interface (API) for connecting to various data sources
2. Establish connection with data source
   • Create and manage connection strings
   • Connect to data source by using different data providers
   • Create code to handle connection exceptions
3. Execute commands and return results from data source
   • Query data from data source
   • Retrieve data from data source as result sets
   • Manage result sets
   • Manage exceptions when retrieving data
4. Modify data in data source
   • Insert, update or delete data
   • Manage data integrity
   • Manage exceptions when modifying data
5. Manage disconnected data
   • Research disconnected data management strategy
   • Ensure that application can deal with disconnected data
6. Document data-access layer
   • Document code
   • Document database connectivity

Performance Evidence

Evidence of the ability to:

select and code the data-access layer of multi-layer applications

retrieve and update data from various data sources.

Note: If a specific volume or frequency is not stated, then evidence must be provided at least once.

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Knowledge Evidence

To complete the unit requirements safely and effectively, the individual must:

describe the features of object-oriented design and multi-layer applications

outline relational database management systems

describe object-oriented programming at an intermediate level

outline the principles of a Structured Query Language (SQL).

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