Hi, i'm having a troubles detecting auto-increment on reflected tables
across different db types.
There is same manually created table in multiple databases of different
type:
sqlite3 test.db 'create table project (id int primary key not null)'
Then reflect it. After reflection, I can check for column attribute
autoincrement.
But sometimes column.autoincrement is 'auto' instead of true/false.
from sqlalchemy import create_engine
from sqlalchemy.ext.automap import automap_base
engine = create_engine('sqlite:///../test.db')
Base = automap_base()
Base.prepare(engine, reflect=True)
cls = Base.classes['project']
print cls.id.prop.columns[0].autoincrement
In my case for db2, oracle, sqlite it is 'auto'. For mysql, mssql,
postglesql it is false.
As I saw in documentation, this 'auto' is useful when defining tables
manually. But what it does on reflected tables?.
The default value is the string "auto" which indicates that a single-column
> primary key that is of an INTEGER type with no stated client-side or
> python-side defaults should receive auto increment semantics automatically;
> all other varieties of primary key columns will not. This includes that
> DDL <https://docs.sqlalchemy.org/en/13/glossary.html#term-ddl> such as
> PostgreSQL SERIAL or MySQL AUTO_INCREMENT will be emitted for this column
> during a table create, as well as that the column is assumed to generate
> new integer primary key values when an INSERT statement invokes which will
> be retrieved by the dialect.
>
> https://docs.sqlalchemy.org/en/13/core/metadata.html#sqlalchemy.schema.Column.params.autoincrement
>
So, how to properly check is column auto incremented or not?
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