Application SW_2 (Computer System General Study Notes)
Characteristics of Relational Databases #
- Tables are composed of a collection of records.
- Fast data classification, sorting, and search speeds, and data integrity is guaranteed.
- Difficult to modify existing schemas and inefficient for processing large amounts of data.
Data Modeling #
- The process of deriving a set of data to constitute a system, defining detailed attributes and identifiers for each set, and visualizing the relationships between these data sets using a defined notation.
Q ) The following is a customer table. #
| Customer Number | Customer Name | Resident Registration Number |
|---|---|---|
| 5 | 김동동 | 050102-4****** |
| 3 | 정봉봉 | 051218-4****** |
| 8 | 서징징 | 050711-4****** |
- A new customer has arrived. The customer number is 7, the customer name is '서봉동', and the resident registration number is '050206-4******'. Write an INSERT statement to insert this data into the customer table.
answer )
INSERT
INTO 고객(고객번호, 고객이름, 주민번호)
VALUSE(7 , '서봉동' , 050206-4******);
Q2 ) Write a command to search for customer numbers whose customer name starts with '서' (Seo). (Note: The customer name is specified as 3 characters long.) #
answer )
SELECT 고객번호
FROM 고객
WHERE 고객이름 LIKE ('서__');