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| author | Matt Riedemann <mriedem@us.ibm.com> | 2016-10-10 11:43:07 -0400 |
|---|---|---|
| committer | Mike Bayer <mike_mp@zzzcomputing.com> | 2016-10-10 11:54:04 -0400 |
| commit | 4b94ee113baab901aee881ad94851587c912f785 (patch) | |
| tree | 449e4ae8a6bffc42c4b95c493237bb0af27d7565 | |
| parent | b9d0e2d5c55f68193fae001bb553a51018ab8ed6 (diff) | |
| download | sqlalchemy-4b94ee113baab901aee881ad94851587c912f785.tar.gz | |
Update the Column.nullable docstring for the primary_key=True case
While reviewing a change that created a new table, the
primary_key column value was set to True but nullable was not
explicitly set, which led to some confusion over the default
behavior for the nullable column value when setting a primary_key.
Looking at the docs it's not clear, but the code shows that if
nullable is not specified, then nullable = not primary_key, so
nullable defaults to False when primary_key is True.
This patch adds a simple clarification to the docs so people
don't have to check the code.
Change-Id: I8553339d56fbae11370c7c6af6d8d4723163be1c
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/312
| -rw-r--r-- | lib/sqlalchemy/sql/schema.py | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index df7e419ca..27ef9e01b 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -1048,10 +1048,14 @@ class Column(SchemaItem, ColumnClause): :param info: Optional data dictionary which will be populated into the :attr:`.SchemaItem.info` attribute of this object. - :param nullable: If set to the default of ``True``, indicates the - column will be rendered as allowing NULL, else it's rendered as - NOT NULL. This parameter is only used when issuing CREATE TABLE - statements. + :param nullable: When set to ``False``, will cause the "NOT NULL" + phrase to be added when generating DDL for the column. When + ``True``, will normally generate nothing (in SQL this defaults to + "NULL"), except in some very specific backend-specific edge cases + where "NULL" may render explicitly. Defaults to ``True`` unless + :paramref:`~.Column.primary_key` is also ``True``, in which case it + defaults to ``False``. This parameter is only used when issuing + CREATE TABLE statements. :param onupdate: A scalar, Python callable, or :class:`~sqlalchemy.sql.expression.ClauseElement` representing a |