A little experience in database design

Design | data | database | Database design
1. Fields are best to use default values, unless those are automatic growth or primary key foreign keys. The character type is the default empty string, the numeric type defaults to 0, and the date type defaults to the system date. The advantage of this is to reduce the unnecessary code of the program and reduce the length of the program code, thereby reducing the possibility of error in the program. For example, when a table contains 20 fields, we need to determine whether it is empty when we read a row of data to the corresponding control. Then, if you do not use the default value, you will increase the corresponding judgment statement, the length of the program may be increased by 60 lines.

The length of the 2 field is designed to take into account the need for future changes, which are generally two units longer than the length of the requirement analysis.

3 It is best to use automatic scaling for character fields which vary in length, which can save user disk space.

4 in the case of database reserved words, the name of the stored procedure table, and so on, in addition to have a certain descriptive, it is best to add a specific prefix. For example, in SQL Server, many people prefer to name a field by name, but name is the reserved word for SQL Server, and the resulting program often fails to find the cause.

5 Complex business logic is best addressed in stored procedures so that it is fast and efficient.