Databases and spreadsheetsA database is used to store information so that it can be searched and sorted in various ways. Each item of information is sorted in various ways. Each item of information is stored in a field. A collection of related fields forms a record. Simple searches can often be created by allowing the user to type the required field information into a blank record, and pressing a search button. More advanced database programs usually use a query language known as SQL (Structural Query Language). This allows users to type statements using logical operators to specify the search conditions.
If you only known part of the field you are searching for, you can use special symbols, called wildcards, to represent combinations of characters. Although the actual wildcard symbols used can vary, most programs use a standardized set of wildcard symbols. A spreadsheet program is used for calculating formulae. It is made up of a grid or array of rectangular boxer called cells, as shown below.
The columns are labelled A, B, C … and the rows of cells are numbered 1, 2, 3 … To refer to a particular cell, you use the column label followed by the row number. For example, the cell in the top left corner of the spreadsheet is A1, the one to the right of it is B1, and the one below it is A2. The cells can contain text, numbers, or formulae. The formulae are written using the cell references, e.g. to add the first three cells in the A column, you would use the formula A1+A2+A3, or the sum function Sum (A1:A3), i.e. the sum of cells A1 to A3. When a formula is assigned to a cell, the result of the formula is displayed in the cell rather than the formula itself. By varying spreadsheet values and formulae, different possible outcomes can be analysed. Other common mathematical symbols used in formulae are shown in the table below.
3 Answer the following questions: 1 What is a database used for? 2 Where is each item of information stored in? 3 What is a spreadsheet program used for? 4 What common mathematical symbols used in formulae do you know?
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