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Anonymous users2024-02-05The database is generally composed of many tables, for example, the school builds a database, which can build a student table (including the student's name, age, student number, class, date of birth), a teacher table (including the teacher's name, age, teaching class, teaching category), a report sheet (including the student's student number, and the grades of each subject), etc. These are the ways in which the files are stored in the database, and try to make sure that the items in a table are closely related and have the same attributes, if this condition cannot be met, a table must be built (the redundancy of the built table has 4 levels). In order to meet the user's query needs, we also need to make a number of views, for example, you can make a view of his items have the name of the student, age, grades of each subject, and the teacher of each subject, etc., we can also export new items according to the existing items, for the purpose of simplicity, for example, the view can add an average grade, we add different permissions and roles to each view, and provide it to different people to query to protect the security of the database.
However, if there are too many tables and too many related items in a view, the query efficiency of the database will be affected. For larger databases, such as those of banks, try to be as efficient as possible. Finally, it is displayed to the user through a web page or a written application.
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Anonymous users2024-02-04There is no need to separate it, just add it directly. It's more convenient.
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Anonymous users2024-02-03It cannot be said that you can store text, but you can also store images, sounds, food and other information. It's not true to say that it consumes space. It is correct to store text, images, sounds, food and other information, but it is wrong to say that this consumes space.
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Anonymous users2024-02-02d: It can store a large amount of data, not only text, but also images, sounds, food and other information. But it consumes space...
This question is about strengths. This space consumption is obviously a disadvantage. So d
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Anonymous users2024-02-01It's not right to store "food"! It's not a refrigerator again!
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Anonymous users2024-01-31The database system solves the needs of data processing and develops a more ideal core mechanism for data processing.
The problem of data storage in the database system has been well solved. The high-speed processing power and mass storage of computers provide the conditions for automating data management.
The database system is a kind of ideal data processing system developed to meet the needs of data processing, and it is also a software system that provides data for the actual operational storage, maintenance and application system, and is a collection of storage media, processing objects and management systems.
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Anonymous users2024-01-30The problem to be solved is that you need to look at the information in the database as much as possible.
Otherwise, no one else will be able to understand the questions asked.
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Anonymous users2024-01-29Access is like that, no matter how you optimize it, change the database.
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Anonymous users2024-01-28Copy the original database and put it in the new one.
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Anonymous users2024-01-271 What should I pay attention to when creating a database?
The database can be set to expand when it is created, but the size of the database is not fixed, and its data is constantly increasing in real time. Be careful not to create user objects in the master database.
2 How do I determine the size of my database?
When creating a database, a missing wheel can create its size.
3 Compare methods for determining data files and log files when creating a database using different methods.
4 Is it possible to create a user object in the master database? Why?
Do not create any user objects in the master database, because the master database contains system tables that store system information used by SQL Server.
5 What are the ways in which the database can be modified?
1) Open Enterprise Manager, serve the Joyce group, and then SQL Server Server.
2) In the "Databases" folder, right-click the database you want to change (e.g. bbsdb), and then click the "Properties" command to open the database belongs to the trust dialog box.
It is also possible to modify the database with transanct-sql.
The statement is: alter database
select ,from emp e left jion dept don ;
Left Company. The left link is, the left side prevails, and the right side is useless to make up for it. >>>More
You can make an information query system, if you haven't done it before, it is recommended to use ASP to write it first, this is relatively simple, even people who do not have a basic knowledge of network programming can get started in a short period of time. The written web program can be called on the network, and different permissions can be set for different users. In this way, you can achieve the function you want, but this is only the basic, and you should learn more deeply to achieve more complete functions. >>>More
It seems that there is something called triggers in the DB, and there seems to be another thing called transactions.
First: you are lazy and push everything to someone else.
Second: There are no bonus points for your question. >>>More
When changes to data affect the index, the information in the index can be spread out across the database. Reindexing reorganizes the storage of indexed data (and in the case of clustered indexes, table data) and defragments it. This improves disk performance by reducing the number of page reads required to obtain the requested data. >>>More