Everyone many times heard such a phrase as"Database". So what are they? Databases are just information models, with which you can store information in a strictly ordered form. Also with their help it is possible to save data on objects endowed with similar properties.
To create a new database, you need to firstdetermine what types and structures of data will be used in it (otherwise you can get completely different than what was required, because the information contained in the databases must be structured).
Now the following types of databases are used: network, table and hierarchical. Of course, in many respects the choice is conditioned by personal preferences and specificity of the information with which the work is conducted.
The most popular type is tabular 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 on the database. You can create databases of this kind with the help of 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 tabular database can beis presented as a simple two-dimensional table. Each row of such a table is alternately filled with the values of an object, and the property values are displayed in separate columns.
The columns of a similar table are called fields. All fields are marked with different names and contain data showing the required parameter values.
In this regard, let us recall once again that if we classify types of databases on the ease of creating and filling the database table will occupy the first place just because of this property.
Object records - naming of individual linestables of such a database. These entries themselves are programmatically divided into several fields using table columns, so all records are sets of required values that are contained in the fields.
If we were to consider other types of databases,now I would have to describe much more special terms. In order to characterize the table base, there are three. We have already learned about fields and records about the object, now we introduce the definition of the key field.
The key field is one of the fields in the table, the value given in it, specifically characterizes any entry contained in the cells of the table.
The key field often contains a data type of the form "counter". Less commonly, the following types of data are used: "inventory number", "product code", etc.
The types of the fields themselves are usually determined by the data that is in them. The main types are: "counter", "text", "numeric", "date / time", "money", "logical", "hyperlink".
Each type is used, based on whichthe result is required. It is unreasonable, you must agree, to use the type of "hyperlink" where the "date / time" option is required. If you make such a substitution, then all the work will go, it's called, awry, as a result of which the data can be counted incorrectly.
That's why we should distinguish between the individual types of databases and the types of fields represented in them.
