ONE to MANY关联表的ID主键跳数与POSTGRESQL

Question

我遇到一个问题，table 的 users 和 posts 的 id 列以增量方式跳跃

users 并且有很多 notes ==> 一对多关系

table users

id | email | first_name | last_name | password
====================================
1  |1@a.com| john       |       den | 23ojonknen4
2  |2@a.com| jenn       |       dub | rfknkn4j4r4
5  |3@a.com| jai        |       dan | 9jikddjk4nj

table notes

id | note_name | note_content | user_id
=======================================
3  | name one  | this is yes  | 1
4  | name two  | this is no   | 5

正在发生的是两个 table 跳转的 id 列...如果笔记的 id 中有 3，那么下一个用户将是 4

我该如何解决这个问题？还是这正常？

这里是用于创建模式的 alembic 文件

from alembic import op
import sqlalchemy as sa


revision = 'master'
down_revision = None
branch_labels = None
depends_on = None


def upgrade():
    op.create_table(
        'users',
        
        sa.Column("id", sa.Integer, primary_key=True),
        sa.Column("email", sa.String(254), nullable=False, index=True, unique=True),
        sa.Column("first_name", sa.String(150), nullable=False),
        sa.Column("last_name", sa.String(150), nullable=False),
        sa.Column("password", sa.String(128), nullable=False),
    )

    op.create_table(
        'notes',
        
        sa.Column("id", sa.Integer, primary_key=True),
        sa.Column("note_name", sa.String(254)),
        sa.Column("note_content", sa.String(254)),
        sa.Column("user_id", sa.Integer, sa.ForeignKey("users.id")),
    )

def downgrade():
    op.drop_table('users')
    op.drop_table('notes')

这是我的 models.py 文件中的内容，用于 python 与数据库交互

from sqlalchemy import Table, Column, Integer, String, Float, Boolean, DateTime, MetaData, Sequence, ForeignKey
from sqlalchemy.orm import relationship

metadata = MetaData()

users = Table(
    "users", metadata,
    Column("id", Integer, primary_key=True),
    Column("email", String(254), nullable=False, index=True, unique=True),
    Column("first_name", String(150), nullable=False),
    Column("last_name", String(150), nullable=False),
    Column("password", String(128), nullable=False),
)


notes = Table(
    "notes", metadata,
    Column("id", Integer, primary_key=True),
    Column("note_name", String(254)),
    Column("note_content", String(254)),
    Column("user_id", Integer, ForeignKey("users.id")),
)

我做错了什么，我该如何解决这个问题？

UPDATE

-# \d

                     List of relations
 Schema |          Name          |   Type   |    Owner     
--------+------------------------+----------+--------------
 public | alembic_version        | table    | db_user
 public | pg_stat_statements     | view     | db_user
 public | notes                  | table    | db_user
 public | notes_id_seq           | sequence | db_user
 public | users                  | table    | db_user
 public | users_id_seq           | sequence | db_user
(6 rows)





-# \d users
                                         Table "public.users"
    Column    |            Type             | Collation | Nullable |               Default                
--------------+-----------------------------+-----------+----------+--------------------------------------
 id           | integer                     |           | not null | nextval('users_id_seq'::regclass)
 email        | character varying(254)      |           | not null | 
 first_name   | character varying(150)      |           | not null | 
 last_name    | character varying(150)      |           | not null | 
 password     | character varying(128)      |           | not null |  
Indexes:
    "users_pkey" PRIMARY KEY, btree (id)             
    "ix_users_email" UNIQUE, btree (email)
Referenced by:
    TABLE "notes" CONSTRAINT "notes_user_id_fkey" FOREIGN KEY (user_id) REFERENCES users(id)




-# \d notes
                                             Table "public.notes"
       Column        |            Type             | Collation | Nullable |                   Default                   
---------------------+-----------------------------+-----------+----------+---------------------------------------------
 id                  | integer                     |           | not null | nextval('notes_id_seq'::regclass)
 note_name           | character varying(254)      |           |          | 
 note_content        | character varying(254)      |           |                   | 
 user_id             | integer                     |           |          | 
Indexes:
    "notes_pkey" PRIMARY KEY, btree (id)
Foreign-key constraints:
    "notes_user_id_fkey" FOREIGN KEY (user_id) REFERENCES users(id)

这是一个示例查询，用于将行插入 users table

    query = "INSERT INTO users VALUES (nextval('users_id_seq'), :email, :password)"
    return database.execute(query, values={"email": user.email, "password": user.password})

这是一个示例查询，用于将行插入 notes table

    query = "INSERT INTO notes VALUES (nextval('users_id_seq'), :note_name, :note_content, :user_id)"
    return database.execute(query, values={"note_name": note.name, "note_content": note.content, "user_id": user.id})

could this the issue?

query = "INSERT INTO notes VALUES (nextval('users_id_seq'),
:note_name, :note_content, :user_id)"

将nextval('users_id_seq')更改为nextval('notes_id_seq')?

Answer 1

what is happening is the id column of the two tables jump...if there is 3 in id of notes, then next if for users will be 4

how can i fix this issue? or is this normal?

是的，这完全正常。自动生成的数字不是严格连续的；引擎会尽最大努力使它们连续，但在缓冲、回滚、多线程等条件下，这在实践中不会发生。

您实际需要的关键功能是这些数字应始终唯一。如您所见，条件已满足，这就是保持数据完整性所需的全部内容。

Answer 2

修复是修复填充注释 table

的 INSERT 查询

来自

query = "INSERT INTO notes VALUES (nextval('users_id_seq'), :note_name, :note_content, :user_id)"
return database.execute(query, values={"note_name": note.name, "note_content": note.content, "user_id": user.id})

到

query = "INSERT INTO notes VALUES (nextval('notes_id_seq'), :note_name, :note_content, :user_id)"
return database.execute(query, values={"note_name": note.name, "note_content": note.content, "user_id": user.id})

这解决了我的问题

ONE to MANY关联表的ID主键跳数与POSTGRESQL

ID primary key of ONE to MANY related tables jumping numbers with POSTGRESQL

sql

postgresql

sqlalchemy

fastapi

alembic