Method Steps for Using Native sql Statements in django

raw

# row Method : (Doped with native sql And orm The operation to perform) 
res = CookBook.objects.raw('select id as nid from epos_cookbook where id>%s', params=[1, ])
print(res.columns) # ['nid']
print(type(res)) # <class 'django.db.models.query.RawQuerySet'>

#  In select The data queried in it orm What's inside 11 Correspondence 
res = CookBook.objects.raw("select * from epos_cookbook")
print(res)
for i in res:
  print(i.create_date)
  print(i)
  
res = CookBook.objects.raw('select * from epos_cookbook where id>%s', params=[1, ])
#  You can add parameters later 
print(res)
for i in res:
  # print(i.create_date)
  print(i)

extra

## select Provide simple data 
# SELECT age, (age > 18) as is_adult FROM myapp_person;
Person.objects.all().extra(select={'is_adult': "age > 18"}) #  Add to select Back 

## where Provide query criteria 
# SELECT * FROM myapp_person WHERE first||last ILIKE 'jeffrey%';
Person.objects.all().extra(where=["first||last ILIKE 'jeffrey%'"]) #  Plus 1 A where Condition 

## table Join other tables 
# SELECT * FROM myapp_book, myapp_person WHERE last = author_last
Book.objects.all().extra(table=['myapp_person'], where=['last = author_last']) #  Plus from Back 

## params Adding parameters 
# !!  The wrong way  !!
first_name = 'Joe' #  If first_name Among them SQL A specific character will be vulnerable 
Person.objects.all().extra(where=["first = '%s'" % first_name])
#  Correct way 
Person.objects.all().extra(where=["first = '%s'"], params=[first_name])

connection (similar to pymysql)

from django.db import connection

 cursor=connection.cursor()
 #  If you need to configure the database 
 # cursor=connection['default'].cursor() 
 
 cursor.execute('select * from app01_book')

 ret=cursor.fetchall()

 print(ret)
 #((2, ' Hourly light ', Decimal('10.00'), 2), (3, ' The future can be expected ', Decimal('33.00'), 1), (4, ' Break the wall in your mind ', Decimal('11.00'), 2), (5, ' Time goes by ', Decimal('11.00'), 3))

Note: If division (%) is used in the sql statement, you need to use%% to escape, because% is mostly used to format the output in str.