1. The meaning of "table" in database: data organized into tabular form. A table consists of several rows and columns. The columns are called fields or attributes, and the rows are called records or tuples.
2. DBMS is the abbreviation of Dtabase Management System. Common ones include SQL Server, Oracle, DB2, etc.
3. Key terms set the relationship between tables, and indexes are a mechanism to improve data retrieval speed.
4. The field in which each value can uniquely identify a record is called the primary key. Other primary key fields added to a table in order to establish relationships between tables are foreign keys.
5. Relational databases are suitable for storing large-scale data.
6. The components of a database system include three parts: data files, DBMS, and applications.
7. DBMS is the intermediary between applications and data files.
8. The database system exists in the following forms:
9. When filtering data, you need to consider the attributes of the data. The attributes also become patterns (internal patterns), specifically the type of data (numbers, strings, etc.).
10. The primary key can be served by only one field, or multiple fields can be combined together to form a composite primary key.
11. An index table is a data structure that stores the value of a field and the location of the record corresponding to the field.
12. Indexes can improve retrieval speed, but indexes cannot be set for all fields because this will reduce the speed of inserting or updating data.
13. The order of designing the system: Design the database first, then design the user interface.
14. The types of operations performed on the database are usually called CRUD. That is, record insertion (CREATE), retrieval (REFER), update (UPDATE), and deletion (DELETE).