Tag:Base table

  • 16 multi meter design

    Time:2021-10-1

    1. Table design ”’ Basemodel base table is_delete、create_time、orders、updated_time The following four tables inherit from the base table and can inherit two fields Book table: name、price、img、authors、publish is_delete、create_time、orders、updated_time Publish table: name、address is_delete、create_time、orders、updated_time Author table: name、age is_delete、create_time、orders、updated_time Authordetail table: mobile, author is_delete、create_time、orders、updated_time ”’ 2. Create base table (Note: set Abstract = true) from django.db import models class BaseModel(models.Model): […]

  • DRF – book series connection table interface

    Time:2021-8-22

    be careful: #Note: for all future data deletion, try to use soft deletion, and use a field to mark whether to delete, rather than really delete from the database -Benefits: 1. Deleting data in this way will not affect the index and cause index invalidation 2. The user data saved before is still available for […]

  • Oracle data dictionary

    Time:2020-9-18

    Composition of data dictionary — two kinds of views Static data dictionary: describes the information in the database The data is often static. Dynamic data dictionary: information describing instances It reflects the running status of data office and the running information of database instance, which is often changeable. users ALL_USERS–lists all users of the database […]

  • Oracle view

    Time:2020-3-28

    Oracle view In project development, multi table query is sometimes used. There are many methods, such as association, such as view, but for query, view query is the fastest. If you have a lot of field information in your database, you need to query the whole table, such as two table query. We can extract […]

  • Database objects

    Time:2019-12-15

    Synonyms are aliases of database objects; sequences are used to generate unique and continuous sequence numbers; View is a virtual table based on one or more tables; index is an optional structure related to tables, which is used to improve the performance of SQL statement execution I. database object: Mode object: Database object is a […]