sqlalchemy.dialects postgresql Example Code

postgresql is a callable within the sqlalchemy.dialects module of the SQLAlchemy project.

mssql, mysql, oracle, and sqlite are several other callables with code examples from the same sqlalchemy.dialects package.

Example 1 from GeoAlchemy2

GeoAlchemy2 (project documentation and PyPI package information) extends SQLAlchemy with new data types for working with geospatial databases, particularly PostGIS, which is a spatial database extender for PostgreSQL. The project is provided as open source under the MIT license.

GeoAlchemy2 / geoalchemy2 / types.py

# types.py
import warnings

from sqlalchemy.types import UserDefinedType, Integer
from sqlalchemy.sql import func
from sqlalchemy.dialects import postgresql
from sqlalchemy.dialects.postgresql.base import ischema_names

try:
    from .shape import to_shape
    SHAPELY = True
except ImportError:
    SHAPELY = False


from .comparator import BaseComparator, Comparator
from .elements import WKBElement, WKTElement, RasterElement, CompositeElement
from .exc import ArgumentError


class _GISType(UserDefinedType):

    name = None

    from_text = None

    as_binary = None

    comparator_factory = Comparator



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



    def __init__(self, *args, **kwargs):
        kwargs['geometry_type'] = None
        kwargs['srid'] = -1
        super(Raster, self).__init__(*args, **kwargs)
        self.extended = None


class CompositeType(UserDefinedType):

    typemap = {}

    class comparator_factory(UserDefinedType.Comparator):
        def __getattr__(self, key):
            try:
                type_ = self.type.typemap[key]
            except KeyError:
                raise KeyError("Type '%s' doesn't have an attribute: '%s'"
                               % (self.type, key))

            return CompositeElement(self.expr, key, type_)


class GeometryDump(CompositeType):

    typemap = {'path': postgresql.ARRAY(Integer), 'geom': Geometry}


ischema_names['geometry'] = Geometry
ischema_names['geography'] = Geography
ischema_names['raster'] = Raster



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

Example 2 from marshmallow-sqlalchemy

marshmallow-sqlalchemy (project documentation) is a code library that makes it easier to use SQLAlchemy with the Marshmallow data serialization tool.

The marshmallow-sqlalchemy project is provided as open source under the MIT license.

marshmallow-sqlalchemy / src/marshmallow_sqlalchemy / convert.py

# convert.py
import inspect
import functools
import warnings

import uuid
import marshmallow as ma
from marshmallow import validate, fields
from sqlalchemy.dialects import postgresql, mysql, mssql
from sqlalchemy.orm import SynonymProperty
import sqlalchemy as sa

from .exceptions import ModelConversionError
from .fields import Related, RelatedList


def _is_field(value):
    return isinstance(value, type) and issubclass(value, fields.Field)


def _has_default(column):
    return (
        column.default is not None
        or column.server_default is not None
        or _is_auto_increment(column)
    )


def _is_auto_increment(column):
    return column.table is not None and column is column.table._autoincrement_column


def _postgres_array_factory(converter, data_type):
    return functools.partial(
        fields.List, converter._get_field_class_for_data_type(data_type.item_type)
    )


class ModelConverter:

    SQLA_TYPE_MAPPING = {
        sa.Enum: fields.Field,
        sa.JSON: fields.Raw,
        postgresql.BIT: fields.Integer,
        postgresql.OID: fields.Integer,
        postgresql.UUID: fields.UUID,
        postgresql.MACADDR: fields.String,
        postgresql.INET: fields.String,
        postgresql.CIDR: fields.String,
        postgresql.JSON: fields.Raw,
        postgresql.JSONB: fields.Raw,
        postgresql.HSTORE: fields.Raw,
        postgresql.ARRAY: _postgres_array_factory,
        postgresql.MONEY: fields.Decimal,
        postgresql.DATE: fields.Date,
        postgresql.TIME: fields.Time,
        mysql.BIT: fields.Integer,
        mysql.YEAR: fields.Integer,
        mysql.SET: fields.List,
        mysql.ENUM: fields.Field,
        mysql.INTEGER: fields.Integer,
        mysql.DATETIME: fields.DateTime,
        mssql.BIT: fields.Integer,
    }
    DIRECTION_MAPPING = {"MANYTOONE": False, "MANYTOMANY": True, "ONETOMANY": True}

    def __init__(self, schema_cls=None):
        self.schema_cls = schema_cls

    @property
    def type_mapping(self):
        if self.schema_cls:
            return self.schema_cls.TYPE_MAPPING
        else:
            return ma.Schema.TYPE_MAPPING

    def fields_for_model(
        self,
        model,
        *,


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

Example 3 from sqlalchemy-datatables

sqlalchemy-datatables (PyPI package information) is a helper library that makes it easier to use SQLAlchemy with the jQuery JavaScript DataTables plugin. This library is designed to be web framework agnostic and provides code examples for both Flask and Pyramid.

The project is built and maintained by Michel Nemnom (Pegase745) and is open sourced under the MIT license.

sqlalchemy-datatables / datatables / datatables.py

# datatables.py
from __future__ import absolute_import

import math

from sqlalchemy import Text, func, or_
from sqlalchemy.dialects import mysql, postgresql, sqlite

from datatables.clean_regex import clean_regex
from datatables.search_methods import SEARCH_METHODS


class DataTables:

    def __init__(self, request, query, columns, allow_regex_searches=False):
        self.params = dict(request)
        if 'sEcho' in self.params:
            raise ValueError(
                'Legacy datatables not supported, upgrade to >=1.10')
        self.query = query
        self.columns = columns
        self.results = None
        self.allow_regex_searches = allow_regex_searches

        self.cardinality_filtered = 0

        self.cardinality = 0

        self.yadcf_params = []
        self.filter_expressions = []
        self.error = None


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


            column_nr = int(self.params.get('order[{:d}][column]'.format(i)))
            column = self.columns[column_nr]
            direction = self.params.get('order[{:d}][dir]'.format(i))
            sort_expr = column.sqla_expr
            if direction == 'asc':
                sort_expr = sort_expr.asc()
            elif direction == 'desc':
                sort_expr = sort_expr.desc()
            else:
                raise ValueError(
                    'Invalid order direction: {}'.format(direction))
            if column.nulls_order:
                if column.nulls_order == 'nullsfirst':
                    sort_expr = sort_expr.nullsfirst()
                elif column.nulls_order == 'nullslast':
                    sort_expr = sort_expr.nullslast()
                else:
                    raise ValueError(
                        'Invalid order direction: {}'.format(direction))

            sort_expressions.append(sort_expr)
            i += 1
        self.sort_expressions = sort_expressions

    def _get_regex_operator(self):
        if isinstance(self.query.session.bind.dialect, postgresql.dialect):
            return '-'
        elif isinstance(self.query.session.bind.dialect, mysql.dialect):
            return 'REGEXP'
        elif isinstance(self.query.session.bind.dialect, sqlite.dialect):
            return 'REGEXP'
        else:
            raise NotImplementedError(
                'Regex searches are not implemented for this dialect')



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

Example 4 from sqlalchemy-utils

sqlalchemy-utils (project documentation and PyPI package information) is a code library with various helper functions and new data types that make it easier to use SQLAlchemy when building projects that involve more specific storage requirements such as currency. The wide array of data types includes ranged values and aggregated attributes.

sqlalchemy-utils / sqlalchemy_utils / expressions.py

# expressions.py
import sqlalchemy as sa
from sqlalchemy.dialects import postgresql
from sqlalchemy.ext.compiler import compiles
from sqlalchemy.sql.expression import ColumnElement, FunctionElement
from sqlalchemy.sql.functions import GenericFunction

from .functions.orm import quote


class array_get(FunctionElement):
    name = 'array_get'


@compiles(array_get)
def compile_array_get(element, compiler, **kw):
    args = list(element.clauses)
    if len(args) != 2:
        raise Exception(
            "Function 'array_get' expects two arguments (%d given)." %
            len(args)
        )

    if not hasattr(args[1], 'value') or not isinstance(args[1].value, int):
        raise Exception(
            "Second argument should be an integer."
        )
    return '(%s)[%s]' % (
        compiler.process(args[0]),
        sa.text(str(args[1].value + 1))
    )


class row_to_json(GenericFunction):
    name = 'row_to_json'
    type = postgresql.JSON


@compiles(row_to_json, 'postgresql')
def compile_row_to_json(element, compiler, **kw):
    return "%s(%s)" % (element.name, compiler.process(element.clauses))


class json_array_length(GenericFunction):
    name = 'json_array_length'
    type = sa.Integer


@compiles(json_array_length, 'postgresql')
def compile_json_array_length(element, compiler, **kw):
    return "%s(%s)" % (element.name, compiler.process(element.clauses))


class Asterisk(ColumnElement):
    def __init__(self, selectable):
        self.selectable = selectable


@compiles(Asterisk)
def compile_asterisk(element, compiler, **kw):


## ... source file continues with no further postgresql 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