Every time I heard such a phrase as “databases”. So what are they? Databases are just information models with which you can save information in a strictly ordered form. It is also possible to save data on objects endowed with similar properties with their help.
To create a new database, you first need to determine what types and structures of data will be used in it (otherwise, you can get quite the wrong thing, because the information contained in the databases must be structured).
Now the following types of databases are used: network, tabular and hierarchical. Of course, the choice is largely due to personal preferences and the specifics of the information that is being worked on.
The most popular type is table databases. They consist of a simple list of objects of a similar type, in other words, objects endowed with identical properties. This type is also leading because it allows you to spend much less time compiling databases. Bases of this kind can be compiled using the same Excel, in the cells of the main window of which you can enter all types of data in spreadsheets, namely: text, formulas and numbers.
In addition, a table database can be represented as a simple two-dimensional table. Each row of such a table is alternately filled with the values of an object, and the values of the properties are displayed in separate columns.
The columns of such a table are called fields. All fields are marked with different names and contain data that demonstrates the required parameter values.
In this regard, we recall once again that if we classify the types of databases according to the degree of simplicity of creation and filling, then the table databases will take first place just because of this property.
Entity records - naming of individual rows of a table in such a database. These records themselves are programmatically divided into several fields using table columns, so all records are sets of the required values that are contained in the fields.
If we considered other types of databases, now we would have to describe much more special terms. In order to characterize the table base, three are enough. We already learned about what fields and records about an object are; now we will introduce a definition of a key field.
A key field is one of the fields in the table, the value given in which specifically characterizes any record contained in the cells of the table.
The key field often contains a data type of the form “counter”. Less commonly used are the following data types: “inventory number”, “product code”, etc.
The types of fields themselves are usually determined by the data in them. The main types: “counter”, “text”, “numerical”, “date / time”, “money”, “logical”, “hyperlink”.
Each type is used based on which result is required. It’s unreasonable to agree to use the “hyperlink” type where the “date / time” option is necessary. If you make such a substitution, then all the work will go, as they say, awry, as a result of which the data can be calculated incorrectly.
That is why it is necessary to distinguish between individual types of databases and types of fields presented in them.