sqlalchemy.sql.expression ColumnClause Example Code

ColumnClause is a class within the sqlalchemy.sql.expression module of the SQLAlchemy project.

ClauseElement, ColumnElement, Executable, FunctionElement, and UnaryExpression are several other callables with code examples from the same sqlalchemy.sql.expression package.

Example 1 from alembic

Alembic (project documentation and PyPI page) is a data migrations tool used with SQLAlchemy to make database schema changes. The Alembic project is open sourced under the MIT license.

alembic / alembic / ddl / postgresql.py

# postgresql.py
import logging
import re

from sqlalchemy import Column
from sqlalchemy import Numeric
from sqlalchemy import text
from sqlalchemy import types as sqltypes
from sqlalchemy.dialects.postgresql import BIGINT
from sqlalchemy.dialects.postgresql import ExcludeConstraint
from sqlalchemy.dialects.postgresql import INTEGER
from sqlalchemy.sql.expression import ColumnClause
from sqlalchemy.sql.expression import UnaryExpression
from sqlalchemy.types import NULLTYPE

from .base import alter_column
from .base import alter_table
from .base import AlterColumn
from .base import ColumnComment
from .base import compiles
from .base import format_column_name
from .base import format_table_name
from .base import format_type
from .base import RenameTable
from .impl import DefaultImpl
from .. import util
from ..autogenerate import render
from ..operations import ops
from ..operations import schemaobj
from ..operations.base import BatchOperations
from ..operations.base import Operations
from ..util import compat
from ..util import sqla_compat


log = logging.getLogger(__name__)


## ... source file abbreviated to get to ColumnClause examples ...


        return "%(prefix)screate_exclude_constraint(%(args)s)" % {
            "prefix": render._alembic_autogenerate_prefix(autogen_context),
            "args": ", ".join(args),
        }
    else:
        args = [
            "(%s, %r)"
            % (_render_potential_column(sqltext, autogen_context), opstring)
            for sqltext, name, opstring in constraint._render_exprs
        ]
        if constraint.where is not None:
            args.append(
                "where=%s"
                % render._render_potential_expr(
                    constraint.where, autogen_context
                )
            )
        args.extend(["%s=%r" % (k, v) for k, v in opts])
        return "%(prefix)sExcludeConstraint(%(args)s)" % {
            "prefix": _postgresql_autogenerate_prefix(autogen_context),
            "args": ", ".join(args),
        }


def _render_potential_column(value, autogen_context):
    if isinstance(value, ColumnClause):
        template = "%(prefix)scolumn(%(name)r)"

        return template % {
            "prefix": render._sqlalchemy_autogenerate_prefix(autogen_context),
            "name": value.name,
        }

    else:
        return render._render_potential_expr(
            value, autogen_context, wrap_in_text=False
        )



## ... source file continues with no further ColumnClause examples...

Sponsored By

Sentry logo

Software errors are inevitable. Chaos is not. Try Sentry for free.


AssemblyAI logo

The most accurate speech-to-text API. Built for Python developers.

1. Introduction 2. Development Environments 3. Data 4. Web Development 5. Deployment 6. DevOps Changelog What Full Stack Means About the Author Future Directions Page Statuses SQLAlchemy ExtensionsSQLAlchemy Example CodeSQLAlchemy Modelssqlalchemy.databases mysqlsqlalchemy.dialects mssqlsqlalchemy.dialects mysqlsqlalchemy.dialects oraclesqlalchemy.schema DDLsqlalchemy.dialects postgresqlsqlalchemy.sql.expression Functionsqlalchemy.dialects sqlitesqlalchemy.dialects.mysql pymysqlsqlalchemy.dialects.postgresql ARRAYsqlalchemy.dialects.postgresql BIGINTsqlalchemy.dialects.postgresql BITsqlalchemy.dialects.postgresql DOUBLE_PRECISIONsqlalchemy.dialects.postgresql ExcludeConstraintsqlalchemy.dialects.postgresql INTEGERsqlalchemy.dialects.postgresql JSONsqlalchemy.dialects.postgresql TSVECTORsqlalchemy.dialects.postgresql pypostgresqlsqlalchemy.dialects.postgresql.base PGCompilersqlalchemy.dialects.postgresql.base PGIdentifierPreparersqlalchemy.dialects.postgresql.base PGTypeCompilersqlalchemy.dialects.postgresql.psycopg2 PGDialect_psycopg2sqlalchemy.dialects.sqlite pysqlitesqlalchemy.engine Connectionsqlalchemy.engine Enginesqlalchemy.engine create_enginesqlalchemy.engine defaultsqlalchemy.engine urlsqlalchemy.engine.default DefaultDialectsqlalchemy.engine.interfaces ExecutionContextsqlalchemy.engine.result ResultMetaDatasqlalchemy.engine.result RowProxysqlalchemy.engine.strategies EngineStrategysqlalchemy.engine.strategies MockEngineStrategysqlalchemy.engine.url make_urlsqlalchemy.events SchemaEventTargetsqlalchemy.exc ArgumentErrorsqlalchemy.exc DataErrorsqlalchemy.exc DatabaseErrorsqlalchemy.exc IntegrityErrorsqlalchemy.exc InvalidRequestErrorsqlalchemy.exc NoInspectionAvailablesqlalchemy.exc NoSuchTableErrorsqlalchemy.exc OperationalErrorsqlalchemy.exc ProgrammingErrorsqlalchemy.exc UnsupportedCompilationErrorsqlalchemy.ext compilersqlalchemy.ext.associationproxy AssociationProxysqlalchemy.ext.automap automap_basesqlalchemy.ext.compiler compilessqlalchemy.ext.declarative DeclarativeMetasqlalchemy.ext.declarative declarative_basesqlalchemy.ext.hybrid hybrid_methodsqlalchemy.ext.hybrid hybrid_propertysqlalchemy.ext.mutable Mutablesqlalchemy.inspection inspectsqlalchemy.orm ColumnPropertysqlalchemy.orm CompositePropertysqlalchemy.orm Loadsqlalchemy.orm Querysqlalchemy.orm RelationshipPropertysqlalchemy.orm SynonymPropertysqlalchemy.orm aliasedsqlalchemy.orm attributessqlalchemy.orm backrefsqlalchemy.orm class_mappersqlalchemy.orm column_propertysqlalchemy.orm compositesqlalchemy.orm interfacessqlalchemy.orm mappersqlalchemy.orm mapperlibsqlalchemy.orm object_mappersqlalchemy.orm object_sessionsqlalchemy.orm relationshipsqlalchemy.orm sessionsqlalchemy.orm sessionmakersqlalchemy.orm strategiessqlalchemy.orm.attributes InstrumentedAttributesqlalchemy.orm.attributes QueryableAttributesqlalchemy.orm.attributes flag_modifiedsqlalchemy.orm.collections InstrumentedListsqlalchemy.orm.exc NoResultFoundsqlalchemy.orm.exc UnmappedClassErrorsqlalchemy.orm.exc UnmappedInstanceErrorsqlalchemy.orm.interfaces MapperPropertysqlalchemy.orm.interfaces PropComparatorsqlalchemy.orm.mapper Mappersqlalchemy.orm.properties ColumnPropertysqlalchemy.orm.properties RelationshipPropertysqlalchemy.orm.query Querysqlalchemy.orm.query QueryContextsqlalchemy.orm.relationships RelationshipPropertysqlalchemy.orm.session Sessionsqlalchemy.orm.session object_sessionsqlalchemy.orm.util AliasedClasssqlalchemy.orm.util AliasedInspsqlalchemy.orm.util identity_keysqlalchemy.pool NullPoolsqlalchemy.pool StaticPoolsqlalchemy.schema CheckConstraintsqlalchemy.schema Columnsqlalchemy.schema CreateIndexsqlalchemy.schema CreateTablesqlalchemy.schema DDLElementsqlalchemy.schema ForeignKeysqlalchemy.schema ForeignKeyConstraintsqlalchemy.schema Indexsqlalchemy.schema PrimaryKeyConstraintsqlalchemy.schema Tablesqlalchemy.sql ClauseElementsqlalchemy.sql columnsqlalchemy.sql expressionsqlalchemy.sql extractsqlalchemy.sql functionssqlalchemy.sql operatorssqlalchemy.sql schemasqlalchemy.sql selectsqlalchemy.sql sqltypessqlalchemy.sql tablesqlalchemy.sql.compiler SQLCompilersqlalchemy.sql.elements ColumnElementsqlalchemy.sql.elements Labelsqlalchemy.sql.expression ClauseElementsqlalchemy.sql.expression ColumnClausesqlalchemy.sql.expression ColumnElementsqlalchemy.sql.expression Executablesqlalchemy.sql.expression FunctionElementsqlalchemy.sql.expression UnaryExpressionsqlalchemy.sql.functions FunctionElementsqlalchemy.sql.functions GenericFunctionsqlalchemy.sql.naming convsqlalchemy.sql.schema Columnsqlalchemy.sql.schema SchemaItemsqlalchemy.sql.sqltypes NullTypesqlalchemy.sql.util ClauseAdaptersqlalchemy.sql.visitors traversesqlalchemy.types Booleansqlalchemy.types Datesqlalchemy.types DateTimesqlalchemy.types Enumsqlalchemy.types Floatsqlalchemy.types Integersqlalchemy.types Intervalsqlalchemy.types NULLTYPEsqlalchemy.types Stringsqlalchemy.types Textsqlalchemy.types Timesqlalchemy.types TypeEnginesqlalchemy.types UserDefinedTypesqlalchemy.types to_instancesqlalchemy.util OrderedDictsqlalchemy.util OrderedSetsqlalchemy.util set_creation_ordersqlalchemy.util symbolsqlalchemy.util topologicalsqlalchemy.util.langhelpers public_factorysqlalchemy.util.langhelpers symbol ...or view the full table of contents.

Full Stack Python

Full Stack Python is an open book that explains concepts in plain language and provides helpful resources for those topics.
Updates via Twitter & Facebook.

Matt Makai 2012-2020