基于django2.2連oracle11g解決版本沖突的問(wèn)題

更新時(shí)間：2020年07月02日 14:43:12 作者：觀想

這篇文章主要介紹了基于django2.2連oracle11g解決版本沖突的問(wèn)題，具有很好的參考價(jià)值，希望對(duì)大家有所幫助。一起跟隨小編過(guò)來(lái)看看吧

上次用django2.2和oracle11g，在migrate的時(shí)候發(fā)生了版本沖突，最終將Oracle升級(jí)到了12c才解決問(wèn)題

那么到底能不能用別的方法來(lái)解決這個(gè)沖突呢？想了個(gè)解決思路，實(shí)踐一下：

用django2.2連Oracle12c環(huán)境下做migrate，創(chuàng)建基礎(chǔ)表

將基礎(chǔ)表導(dǎo)出，再導(dǎo)入到Oracle11g數(shù)據(jù)庫(kù)中

用django2.2連Oracle11g

實(shí)施步驟

1、用django2.2連Oracle12c環(huán)境下做migrate，創(chuàng)建基礎(chǔ)表

在前文中已經(jīng)完成，連接到數(shù)據(jù)庫(kù)，可以看到有10張基礎(chǔ)表

看一張表，比如AUTH_GROUP表，發(fā)現(xiàn)有個(gè)ID字段是用了12c特有的generated語(yǔ)法，除了DJANGO_SESSION外，其他每張表都有一個(gè)自增序列的id字段作為主鍵。

-- Create table
create table AUTH_GROUP
(
 id NUMBER(11) generated by default on null as identity,
 name NVARCHAR2(150)
)
tablespace DJANGO;
-- Create/Recreate primary, unique and foreign key constraints 
alter table AUTH_GROUP
 add primary key (ID)
 using index 
 tablespace DJANGO;
alter table AUTH_GROUP
 add unique (NAME)
 using index 
 tablespace DJANGO;

2. 將基礎(chǔ)表導(dǎo)出，再導(dǎo)入到Oracle11g數(shù)據(jù)庫(kù)中

導(dǎo)出django用戶數(shù)據(jù)庫(kù)，注意使用11g版本

接著導(dǎo)入到11g數(shù)據(jù)庫(kù)中，非常順利

再看AUTH_GROUP表，發(fā)現(xiàn)表結(jié)構(gòu)是一樣的，但是id上面自增序列的默認(rèn)值沒(méi)有了。

-- Create table
create table AUTH_GROUP
(
 id NUMBER(11) not null,
 name NVARCHAR2(150)
)
tablespace DJANGO;
-- Create/Recreate primary, unique and foreign key constraints 
alter table AUTH_GROUP
 add primary key (ID)
 using index 
 tablespace DJANGO;
alter table AUTH_GROUP
 add unique (NAME)
 using index 
 tablespace DJANGO;

3、用django2.2連Oracle11g

修改settings文件，連Oracle11g，然后啟動(dòng)django服務(wù)，果然成功啟動(dòng)

但是，但是，創(chuàng)建admin用戶密碼的時(shí)候就報(bào)錯(cuò)了，ORA-01400: cannot insert NULL into (“DJANGO”.“AUTH_USER”.“ID”)

PS D:\parttime\python\django\guanxiangzhiji> python manage.py createsuperuser
用戶名 (leave blank to use 'administrator'):
電子郵件地址:
Password:
Password (again):
密碼長(zhǎng)度太短。密碼必須包含至少 8 個(gè)字符。
這個(gè)密碼太常見(jiàn)了。
Bypass password validation and create user anyway? [y/N]: y
Traceback (most recent call last):
 File "D:\app\anaconda\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
 return self.cursor.execute(sql, params)
 File "D:\app\anaconda\lib\site-packages\django\db\backends\oracle\base.py", line 510, in execute
 return self.cursor.execute(query, self._param_generator(params))
cx_Oracle.IntegrityError: ORA-01400: cannot insert NULL into ("DJANGO"."AUTH_USER"."ID")

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
 File "manage.py", line 21, in <module>
 main()
 File "manage.py", line 17, in main
 execute_from_command_line(sys.argv)
 File "D:\app\anaconda\lib\site-packages\django\core\management\__init__.py", line 381, in execute_from_command_line
 utility.execute()
 File "D:\app\anaconda\lib\site-packages\django\core\management\__init__.py", line 375, in execute
 self.fetch_command(subcommand).run_from_argv(self.argv)
 File "D:\app\anaconda\lib\site-packages\django\core\management\base.py", line 323, in run_from_argv
 self.execute(*args, **cmd_options)
 File "D:\app\anaconda\lib\site-packages\django\contrib\auth\management\commands\createsuperuser.py", line 61, in execute
 return super().execute(*args, **options)
 File "D:\app\anaconda\lib\site-packages\django\core\management\base.py", line 364, in execute
 output = self.handle(*args, **options)
 File "D:\app\anaconda\lib\site-packages\django\contrib\auth\management\commands\createsuperuser.py", line 156, in handle
 self.UserModel._default_manager.db_manager(database).create_superuser(**user_data)
 File "D:\app\anaconda\lib\site-packages\django\contrib\auth\models.py", line 162, in create_superuser
 return self._create_user(username, email, password, **extra_fields)
 File "D:\app\anaconda\lib\site-packages\django\contrib\auth\models.py", line 145, in _create_user
 user.save(using=self._db)
 File "D:\app\anaconda\lib\site-packages\django\contrib\auth\base_user.py", line 66, in save
 super().save(*args, **kwargs)
 File "D:\app\anaconda\lib\site-packages\django\db\models\base.py", line 741, in save
 force_update=force_update, update_fields=update_fields)
 File "D:\app\anaconda\lib\site-packages\django\db\models\base.py", line 779, in save_base
 force_update, using, update_fields,
 File "D:\app\anaconda\lib\site-packages\django\db\models\base.py", line 870, in _save_table
 result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)
 File "D:\app\anaconda\lib\site-packages\django\db\models\base.py", line 908, in _do_insert
 using=using, raw=raw)
 File "D:\app\anaconda\lib\site-packages\django\db\models\manager.py", line 82, in manager_method
 return getattr(self.get_queryset(), name)(*args, **kwargs)
 File "D:\app\anaconda\lib\site-packages\django\db\models\query.py", line 1186, in _insert
 return query.get_compiler(using=using).execute_sql(return_id)
 File "D:\app\anaconda\lib\site-packages\django\db\models\sql\compiler.py", line 1335, in execute_sql
 cursor.execute(sql, params)
 File "D:\app\anaconda\lib\site-packages\django\db\backends\utils.py", line 99, in execute
 return super().execute(sql, params)
 File "D:\app\anaconda\lib\site-packages\django\db\backends\utils.py", line 67, in execute
 return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
 File "D:\app\anaconda\lib\site-packages\django\db\backends\utils.py", line 76, in _execute_with_wrappers
 return executor(sql, params, many, context)
 File "D:\app\anaconda\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
 return self.cursor.execute(sql, params)
 File "D:\app\anaconda\lib\site-packages\django\db\utils.py", line 89, in __exit__
 raise dj_exc_value.with_traceback(traceback) from exc_value
 File "D:\app\anaconda\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
 return self.cursor.execute(sql, params)
 File "D:\app\anaconda\lib\site-packages\django\db\backends\oracle\base.py", line 510, in execute
 return self.cursor.execute(query, self._param_generator(params))
django.db.utils.IntegrityError: ORA-01400: cannot insert NULL into ("DJANGO"."AUTH_USER"."ID")

原因分析

很明顯，插入到AUTH_USER表時(shí)，沒(méi)有指定ID的值，而ID是主鍵，非空。

因?yàn)樵?2c的環(huán)境下，這個(gè)ID是自增序列，insert語(yǔ)句中不需要指定這個(gè)值。

解決方案

解決方案也應(yīng)運(yùn)而出了，只要為每個(gè)ID列創(chuàng)建一個(gè)11g的序列，創(chuàng)建觸發(fā)器，在插入數(shù)據(jù)時(shí)補(bǔ)上id值就行了。

（1）生成序列。

用sql語(yǔ)句

select 'create sequence seq_'||table_name||' minvalue 1 maxvalue 999999999 start with 1 increment by 1 cache 20;'
 from user_tab_columns
 where column_name='ID';

生成創(chuàng)建序列的批量執(zhí)行語(yǔ)句，并執(zhí)行。

create sequence seq_DJANGO_ADMIN_LOG minvalue 1 maxvalue 999999999 start with 1 increment by 1 cache 20;
create sequence seq_AUTH_USER minvalue 1 maxvalue 999999999 start with 1 increment by 1 cache 20;
create sequence seq_AUTH_USER_GROUPS minvalue 1 maxvalue 999999999 start with 1 increment by 1 cache 20;
create sequence seq_DJANGO_CONTENT_TYPE minvalue 1 maxvalue 999999999 start with 1 increment by 1 cache 20;
create sequence seq_AUTH_GROUP minvalue 1 maxvalue 999999999 start with 1 increment by 1 cache 20;
create sequence seq_AUTH_GROUP_PERMISSIONS minvalue 1 maxvalue 999999999 start with 1 increment by 1 cache 20;
create sequence seq_DJANGO_MIGRATIONS minvalue 1 maxvalue 999999999 start with 1 increment by 1 cache 20;
create sequence seq_AUTH_PERMISSION minvalue 1 maxvalue 999999999 start with 1 increment by 1 cache 20;
create sequence seq_AUTH_USER_USER_PERMISSIONS minvalue 1 maxvalue 999999999 start with 1 increment by 1 cache 20;

（2）創(chuàng)建觸發(fā)器

用SQL語(yǔ)句

select 'create or replace trigger tri_'||table_name||'
 before insert
 on '||table_name||' 
 for each row
 declare
 begin
 :new.id:=seq_'||table_name||'.nextval;
 end tri_'||table_name||';
 /'
 from user_tab_columns
 where column_name='ID';

生成觸發(fā)器腳本：

create or replace trigger tri_DJANGO_MIGRATIONS
	before insert
	on DJANGO_MIGRATIONS
	for each row
declare
begin
	:new.id:=seq_DJANGO_MIGRATIONS.nextval;
end tri_DJANGO_MIGRATIONS;
/
create or replace trigger tri_DJANGO_CONTENT_TYPE
	before insert
	on DJANGO_CONTENT_TYPE
	for each row
declare
begin
	:new.id:=seq_DJANGO_CONTENT_TYPE.nextval;
end tri_DJANGO_CONTENT_TYPE;
/
create or replace trigger tri_AUTH_PERMISSION
	before insert
	on AUTH_PERMISSION
	for each row
declare
begin
	:new.id:=seq_AUTH_PERMISSION.nextval;
end tri_AUTH_PERMISSION;
/
create or replace trigger tri_AUTH_GROUP
	before insert
	on AUTH_GROUP
	for each row
declare
begin
	:new.id:=seq_AUTH_GROUP.nextval;
end tri_AUTH_GROUP;
/
create or replace trigger tri_AUTH_GROUP_PERMISSIONS
	before insert
	on AUTH_GROUP_PERMISSIONS
	for each row
declare
begin
	:new.id:=seq_AUTH_GROUP_PERMISSIONS.nextval;
end tri_AUTH_GROUP_PERMISSIONS;
/
create or replace trigger tri_AUTH_USER
	before insert
	on AUTH_USER
	for each row
declare
begin
	:new.id:=seq_AUTH_USER.nextval;
end tri_AUTH_USER;
/
create or replace trigger tri_AUTH_USER_GROUPS
	before insert
	on AUTH_USER_GROUPS
	for each row
declare
begin
	:new.id:=seq_AUTH_USER_GROUPS.nextval;
end tri_AUTH_USER_GROUPS;
/
create or replace trigger tri_AUTH_USER_USER_PERMISSIONS
	before insert
	on AUTH_USER_USER_PERMISSIONS
	for each row
declare
begin
	:new.id:=seq_AUTH_USER_USER_PERMISSIONS.nextval;
end tri_AUTH_USER_USER_PERMISSIONS;
/
create or replace trigger tri_DJANGO_ADMIN_LOG
	before insert
	on DJANGO_ADMIN_LOG
	for each row
declare
begin
	:new.id:=seq_DJANGO_ADMIN_LOG.nextval;
end tri_DJANGO_ADMIN_LOG;
/

（3）此時(shí)再創(chuàng)建admin用戶，就成功了