SQLAlchemy ON DUPLICATE KEY UPDATE

Question

Is there an elegant way to do an INSERT ... ON DUPLICATE KEY UPDATE in SQLAlchemy? I mean something with a syntax similar to inserter.insert().execute(lis

Answer 1

It's depends upon you. If you want to replace then pass OR REPLACE in prefixes

  def bulk_insert(self,objects,table):
    #table: Your table class and objects are list of dictionary [{col1:val1, col2:vale}] 
    for counter,row in enumerate(objects):
        inserter = table.__table__.insert(prefixes=['OR IGNORE'], values=row)
        try:
            self.db.execute(inserter)
        except Exception as E:
            print E
        if counter % 100 == 0:
            self.db.commit()                    
    self.db.commit()

Here commit interval can be changed to speed up or speed down

Answer 2

Got a simpler solution:

from sqlalchemy.ext.compiler import compiles
from sqlalchemy.sql.expression import Insert

@compiles(Insert)
def replace_string(insert, compiler, **kw):
    s = compiler.visit_insert(insert, **kw)
    s = s.replace("INSERT INTO", "REPLACE INTO")
    return s

my_connection.execute(my_table.insert(replace_string=""), my_values)

Answer 3

I should mention that ever since the v1.2 release, the SQLAlchemy 'core' has a solution to the above with that's built in and can be seen under here (copied snippet below):

from sqlalchemy.dialects.mysql import insert

insert_stmt = insert(my_table).values(
    id='some_existing_id',
    data='inserted value')

on_duplicate_key_stmt = insert_stmt.on_duplicate_key_update(
    data=insert_stmt.inserted.data,
    status='U'
)

conn.execute(on_duplicate_key_stmt)