SUBJECT: HOME ECONOMICS
CLASS: JSS 3
TERM: 1st TERM
FOR WEEKS 7-8
What is a database?
What is database management system?
A database management system (DBMS)A software package that allows for the creation, storage, maintenance, manipulation, and retrieval of large datasets distributed over one or more files. is a software package that allows for the creation, storage, maintenance, manipulation, and retrieval of large datasets that are distributed over one or more files
TYPES OF DATABASE
Five main types of database organization:
A flat-file database is one that only contains a single table of data.
A flat –file databaseA database model whereby all data are stored in a single table. is a database whereby all data are stored in a single, large table.
Below is an example of how our database might look built around a flat file model? The table is separated into rows and columns. A single column represents an attribute, and a single row represents a record in this database. The table below is an example of a flat file database.
15 Meade Lane
16 Rope Street
17 Camel Lane
18 Leather Lane
19 Apple Grove
Another example is the table that shows the properties of seven fishes such as habitat, color, and speed and caretaker schedule table. Since some animals can live on land or in water, two columns are needed for the Habitat properties. Similarly, three columns are needed for the Color properties. This leads to the flat file database shown in the following figure.
Alex :( 6-7am,3-4pm)
A relational database is the type of database that contains two or more tables of data, connected by links called relationship.
A relational database A software package that records information in such a way that data can be accessed without reorganization of the tables.is a collection of tables that are connected in such a way that that data can be accessed without reorganization of the tables. The tables are created such that each column represents a particular attribute.
Practice your understanding of databases by answering the following questions:
A HIERARCHICAL DATABASE
ADVANTAGES OF HIERARCHICAL DATABASE
DISADVANTAGES OF HIERARCHICAL DATABASE
The network model is the type of database that allows many-to-many relationships in a tree-like structure that allows multiple parents.
TERMINOLOGIES USED IN DATABASE
A field is an item of stored data. A field could be a name, an address, city, State and country
From the table above:
Josephine is a filed
Lagos is filed
Lagos (City) is a field
Nigeria is a filed
A record is the collection of fields that relate to a single entity.
For example, we could have a student record that includes fields for the student’s name, address, homeroom, date of birth.
Example: A complete name and address.
Date of birth
A file is a collection of related records. For example, a student file might include all of the records of students enrolled at a school.
Date of birth
25 Accord St
13 Powerline St
A key field is a field in a data file containing information capable of uniquely identifying a record in relation to all other records in the same data file.
FOR WEEK 9-10
Meaning of Spreadsheet package
A spreadsheet package is application software that is made of horizontal (columns) and vertical (rows) which is used in data analysis and calculation.
A spreadsheet is made up of three things: rows, columns and their intersections are called cells. Columns are typically labelled using letters (A, B, C, D,) and rows are typically labelled using numbers (1, 2, 3, 4,). An intersection of a column and a row makes a cell in a spreadsheet
USES OF SPREADSHEET PACKAGES
The following are the uses of spreadsheet
EXAMPLES OF SPREADSHEET
SPREADSHEET FEATURES AND TERMINOLOGIES
There are various spreadsheet terminologies .These are:
A column is a range of cells that extending from top to down (vertical) in a spreadsheet or worksheet. Columns are labeled with letters, for example, column A, column B. The highlighted part of the spreadsheet is a column, and it is labeled B.
A row is the horizontal range of cells that go across the spreadsheet/worksheet from left to right. Numbers are used to label each row’s location. The highlighted part of the spreadsheet is a row, and it is labeled 3.
A cell is the space where a specified row and column intersect. Each CELL is assigned a name according to its COLUMN letter and ROW number. The highlighted part of the spreadsheet is a cell, and it is labeled C3. When naming a cell, you should put the column first and the row second. A cell can contain a value (number), a formula (simple math or more complex formulas called functions).
CELL ADDRESS OR CELL REFERENCE:
Cell address or cell reference is a cell
A range is a group of selected cells which can be next to one another (adjacent) or non-adjacent.
Ranges are identified by cell references e.g. A1:B6 or a name e.g. sales_table.
Labels: (Text with no numerical value) Column A and Row 1 are labels because they contain text. They help identify what we are talking about.
Values: These are numbers insert in each cell of a spreadsheet or worksheet:
WORKSHEET OR SPREADSHEET
A worksheet is a single sheet (page) of rows and columns in a workbook. A worksheet consists of all of the cells on that single sheet.
A workbook is a collection of worksheets which are stored together in a single file and given a single name. Workbooks can contain links between different worksheets.
A set of instructions to manipulate the contents of other cells. These operations can be simple arithmetic operations, or more complex ones. An example would be: + (B1/B4) to divide the value found in cell B1 by the value found in cell B4.
A function is a pre-written formula that makes complex formulas easier to write. They are distinguished from regular formulas by the name of the function. For example the formula=SUM (B1:B4) would add each value in the column B from row 1 to row 4
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