Attention
TYPO3 v11 has reached end-of-life as of October 31th 2024 and is no longer being maintained. Use the version switcher on the top left of this page to select documentation for a supported version of TYPO3.
Need more time before upgrading? You can purchase Extended Long Term Support (ELTS) for TYPO3 v11 here: TYPO3 ELTS.
Upgrade table and field definitions
Each extension in TYPO3 can provide the ext_
file that defines
which tables and fields the extension needs. Gathering all
ext_
files thus defines the complete set of tables, fields and
indexes of a TYPO3 instance to unfold its full functionality. The
Analyze Database Structure section in the
Admin Tools > Maintenance backend module can compare the defined set
with the current active database schema and shows options to align these two by
adding fields, removing fields and so on.
When you upgrade to newer versions of TYPO3 or upgrade an extension, the data definition of tables and fields may have changed. The database structure analyzer detects such changes.
When you install a new extension, any change to the database is performed automatically. When upgrading to a new major version of TYPO3, you should normally go through the upgrade wizard, whose first step is to perform all necessary database changes:
If you want to perform minor updates, update extensions or generally check the functionality of your system, you can go to Admin Tools > Maintenance > Analyze Database Structure:
This tool collects the information from all ext_
files of all
active extensions and compares them with the current database structure. Then it
proposes to perform the necessary changes, grouped by type:
- creating new tables
- adding new fields to existing tables
- altering existing fields
- dropping unused tables and fields
You can choose which updates you want to perform. You can even decide not to create new fields and tables, although that will very likely break your installation.
See also
For more information about the process of upgrading TYPO3, see the Upgrade Guide.
The ext_tables.sql files
As mentioned above, all data definition statements are stored in files named
ext_
, which may exist in any extension.
The peculiarity is that these files may not always contain a complete and valid SQL data definition. For example, the "dashboard" system extension defines a new table for storing dashboards:
CREATE TABLE be_dashboards (
identifier varchar(120) DEFAULT '' NOT NULL,
title varchar(120) DEFAULT '' NOT NULL,
widgets text
);
This is a complete and valid SQL data definition. However, the community
extension "news" extends the tt_
table with additional fields. It
also provides these changes in the form of a SQL CREATE TABLE
statement:
CREATE TABLE tt_content (
tx_news_related_news int(11) DEFAULT '0' NOT NULL,
KEY index_newscontent (tx_news_related_news)
);
The classes which take care of assembling the complete SQL data definition will
compile all the CREATE TABLE
statements for a given table and turn them
into a single CREATE TABLE
statement. If the table already exists,
missing fields are isolated and ALTER TABLE
statements are proposed
instead.
This means that as an extension developer you should always only have
CREATE TABLE
statements in your ext_
files, the system
will handle them as needed.