Manipulate Data
Overview
A database is only as useful as the questions you can ask of it. A garage with three hundred cars in stock does not want to scroll through every row; it wants to see, in one click, only the Fords under $4000, sorted from cheapest to dearest, with the profit on each one worked out automatically. That is what manipulating data means: searching, sorting and calculating so the right information rises to the surface.
In this lesson you will learn to write queries that select exactly the records you want using the operators AND, OR, NOT and the comparisons such as greater than and less than, and to search inside text using wildcards. You will sort data into ascending or descending order on one or more fields, and create calculated fields and summaries that compute totals and averages at run time. These are core skills of the practical database papers.
Objectives
- Perform calculations.
- Use arithmetic operations or numeric functions to perform calculations including calculated fields, calculated controls Use formulae and functions to perform calculations at run time including addition, subtraction, multiplication, division, sum, average, maximum, minimum, count.
- Sort data.
- Use a single criterion, or multiple criteria to sort data into ascending or descending order.
- Search and select data.
- Use a single criterion, or multiple criteria to select subsets of data using a query perform searches using a variety of operators including AND, OR, NOT, LIKE, >, <, =, >=, <=, <> perform searches using wildcards.
Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Manipulate Data. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- Which logical operator returns records only when every condition is true? A. OR B. NOT C. AND D. LIKE Answer: C
- The criterion >=10 placed in a Quantity field selects records where the quantity is: A. less than 10 B. exactly 10 only C. 10 or more D. less than or equal to 10 Answer: C
- Which search would find all colours that begin with the letters Bl? A. *Bl B. Bl* C. *Bl* D. =Bl Answer: B
- A new field defined as Profit: [SPrice] - [PPrice] is an example of a: A. Primary key B. Validation rule C. Calculated field D. Foreign key Answer: C
- Which function returns the number of records in a group? A. SUM B. AVG C. MAX D. COUNT Answer: D
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Recommended Books
Practice Mock Questions
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