我正在尝试使用SQLAlchemy
将数据批量插入到postgres中,但是无法找出如何说它通过唯一约束忽略重复值
我的代码
from sqlalchemy.dialects.postgresql import insert
stmt = insert(User, inline=True)
values = [{"id": 1, "name": "David"}, {"id": 2, "name": "Cris"}]
session.execute(stmt, values)
session.commit()
遇到这样的错误
sqlalchemy.exc.IntegrityError:(psycopg2.IntegrityError)重复键值违反了唯一约束“ uq_users_name”
答案 0 :(得分:3)
默认情况下sqlalchemy不支持ignore_duplicates
选项,因此我们需要通过在查询末尾添加ON CONFLICT DO NOTHING
字符串来向sqlalchemy查询编译器添加自定义方法
from sqlalchemy.dialects.postgresql import insert
from sqlalchemy.ext.compiler import compiles
@compiles(Insert, 'postgresql')
def ignore_duplicates(insert, compiler, **kw):
s = compiler.visit_insert(insert, **kw)
ignore = insert.kwargs.get('postgresql_ignore_duplicates', False)
return s if not ignore else s + ' ON CONFLICT DO NOTHING'
Insert.argument_for('postgresql', 'ignore_duplicates', None)
stmt = insert(User, postgresql_ignore_duplicates=True, inline=True)
values = [{"id": 1, "name": "David"}, {"id": 2, "name": "Cris"}]
session.execute(stmt, values)
session.commit()