Tables

Column types

Access designer	PyAccessKit	Notes
Short Text	Column.text(name, length=255)	allow_zero_length=False, unicode_compression=True, input_mask=
Long Text	Column.long_text(name, rich_text=False, append_only=False)
Number	Column.number(name, size=NumberSize.LONG_INTEGER)	Sizes: BYTE, INTEGER (16-bit), LONG_INTEGER, SINGLE, DOUBLE, REPLICATION_ID; decimal_places=
Number (Decimal)	Column.decimal(name, precision=18, scale=0)	Created with ADO DDL (DAO cannot create decimals)
Currency	Column.currency(name)	Exact, 4 decimal places
AutoNumber	Column.autonumber(name, replication_id=False)	Incrementing Long Integer, or a GUID (Replication ID)
Date/Time	Column.date_time(name)
Yes/No	Column.yes_no(name)	Shown as a check box, as in Access
Hyperlink	Column.hyperlink(name)
OLE Object	Column.ole_object(name)

Every column also accepts required, default, validation_rule, validation_text, description, caption, format, and properties={...} (other Access field properties, set verbatim). Options that do not apply to a type are rejected.

Columns PyAccessKit cannot create yet (Attachment, calculated, multi-valued, Large Number, Date/Time Extended) still appear in to_spec(), as UnsupportedColumn entries that name the Access type, so introspection never silently drops a field.

Defaults and expressions

from datetime import date
from pyaccesskit import Column, Expr

Column.text("Country", default="Belgium")  # rendered as "Belgium"
Column.text("Name", default='O"Brien')  # quotes are escaped for you
Column.currency("Total", default=0)
Column.yes_no("IsActive", default=True)
Column.date_time("Since", default=date(2026, 1, 1))
Column.date_time("CreatedAt", default=Expr("Now()"))  # an Access expression, passed verbatim

On Text columns, a string default is always a value: default="Now()" means the four characters Now(). On other columns, a string must be a literal of the column's type ("42", "True", "#2026-01-31#"). Anything else, such as default="Now()" on a Date/Time column, is rejected with a hint to use Expr(...), which prevents the classic unquoted-default bug.

Keys and indexes

from pyaccesskit import Column, IndexSpec

db.tables.create(
    "People",
    columns=[
        Column.autonumber("PersonID", primary_key=True),
        Column.text("LastName", length=80, indexed=True),  # non-unique index "LastName"
        Column.text("FirstName", length=80),
        Column.text("Email", length=255, unique=True),  # unique index "Email"
    ],
    indexes=[IndexSpec.on("ixFullName", "LastName", "FirstName")],
)

db.tables.create(
    "Enrollment",
    columns=[Column.number("PersonID"), Column.number("CourseID")],
    primary_key=["PersonID", "CourseID"],  # composite primary key, named PrimaryKey as in Access
)

IndexSpec.on(name, *columns, unique=False, ignore_nulls=False, required=False) accepts ("Column", "desc") pairs for descending keys. Limits are checked up front: 32 indexes per table, 10 columns per index, one primary key.

Changing tables

table = db.tables["People"]
table.add_column(Column.text("Phone", length=30))
table.rename_column("Phone", "Mobile")
table.drop_column("Mobile")
table.create_index(IndexSpec.on("ixEmailLast", "Email", "LastName", unique=True))
table.drop_index("ixEmailLast")
table.description = "Everyone we know"
table.rename("Contacts")
db.tables.drop("Contacts", drop_relationships=True)

Table creation is atomic: the table, its fields and its indexes are built and appended in one step. If anything fails afterwards (for example, a property), the table is removed again. Changing a column's type or order is not supported yet. It needs copy-and-migrate, which will come with plan/apply.

Properties

Access stores many settings as DAO properties that only exist once set. properties bags read and write them:

from pyaccesskit import PropertyType

field = db.tables["People"].fields["Email"]
field.properties["Caption"] = "E-mail address"
db.properties["AppTitle"] = "My application"
db.tables["People"].properties.set(
    "MyTag", 7, PropertyType.BYTE
)  # force the DAO type of a new property
print(db.properties.get("StartUpForm"))  # None if not set

Reading a table back

table = db.tables["People"]
[field.name for field in table.fields]
table.fields["Email"].data_type, table.fields["Email"].size
table.primary_key, table.indexes
table.record_count()
spec = table.to_spec()  # canonical TableSpec; relationship-owned indexes are left out