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Elements and Performance Criteria

  1. Design data-access layer (DAL)
  2. Establish a connection with a data source
  3. Execute commands and return results from the data source
  4. Modify data in the data source
  5. Manage disconnected data
  6. Document data-access layer

Required Skills

Required skills

analytical skills to design complex multilayer application model

communication skills to interact with developer to ensure proper implementation

learning skills to investigate potential new techniques to access data from various resources

literacy skills to

read and interpret database design document

read basic technical data

problemsolving skills to develop and refine strategies to access data sources

technical skills to

create code for the dataaccess layer

create structured query language SQL commands to select insert update or delete data

test and debug code

Required knowledge

features of

objectoriented design and multilayer applications

relational database management systems

objectoriented programming at an intermediate level

SQL at a basic level

Evidence Required

The evidence guide provides advice on assessment and must be read in conjunction with the performance criteria required skills and knowledge range statement and the Assessment Guidelines for the Training Package

Overview of assessment

Critical aspects for assessment and evidence required to demonstrate competency in this unit

Evidence of the ability to

design and code the dataaccess layer of multilayer applications

retrieve and update data from various data sources

Context of and specific resources for assessment

Assessment must ensure access to

integrated development environment IDE

data access APIs

database management system software

database files

coding standard

specific tools and licences depending on particular dataaccess API

appropriate learning and assessment support when required

modified equipment for people with special needs

Method of assessment

A range of assessment methods should be used to assess practical skills and knowledge The following examples are appropriate for this unit

review of candidates DAL design

evaluation of candidates dataaccess management strategy

verbal or written questioning to assess candidates knowledge of

multilayer applications

database access

Guidance information for assessment

Holistic assessment with other units relevant to the industry sector workplace and job role is recommended where appropriate

Assessment processes and techniques must be culturally appropriate and suitable to the communication skill level language literacy and numeracy capacity of the candidate and the work being performed

Indigenous people and other people from a nonEnglish speaking background may need additional support

In cases where practical assessment is used it should be combined with targeted questioning to assess required knowledge


Range Statement

The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.

Multi-layer application may include:

business logic layer (BLL)

data-access layer (DAL)

user interface layer (UI).

Data-access application programming interface may relate to:

object-oriented set of libraries used to interact with data sources:

active data objects (ADO.NET)

ADO.NET Entity Framework

Java database connectivity (JDBC)

language integrated query (LINQ).

Data source may include:

databases:

Microsoft SQL server

MySQL

Oracle

Postgre Structured Query Language (Postgre SQL)

fat-files database

internal data

object data sources

XML database.

Data providers may include:

managed providers

Microsoft object linking and embedding (OLE) DB

native providers

open database connection (ODBC)

SQL client

third-party providers.

Query data may include:

access input and output parameters and return values

access stored procedures

create command objects.

Data integrity may include:

cascading deletes

cascading updates

constraints.

Disconnected data may include:

DataSet

DataTable

service data objects (SDO).