Important: Contract relation columns are NOT NULL now 

Description 

The organisational_unit, function_type and location columns of tx_academicpersons_domain_model_contract were nullable integer columns, and their TCA select fields used an empty string (respectively null) as the value of their "please select" item. PostgreSQL rejects an empty string as an integer value, so on that DBMS saving a contract with one of these selects empty failed — and so did every DataHandler localize of a contract whose source row held NULL in one of them, which the reworked translation synchronisation runs into. MySQL, MariaDB and SQLite coerce the empty string to 0 silently, which is why the defect only surfaced on PostgreSQL.

Both sides now follow the core convention for optional single-value relation selects: the empty item value is 0, the field default is 0, and the three columns are int(11) unsigned DEFAULT '0' NOT NULL.

Impact 

The database analyzer will suggest altering the three columns. On installations where existing rows hold NULL in one of them — rows created before this version and never saved since — the ALTER TABLE fails on PostgreSQL and on MySQL in strict mode until those values are updated to 0:

UPDATE tx_academicpersons_domain_model_contract
    SET organisational_unit = 0 WHERE organisational_unit IS NULL;
UPDATE tx_academicpersons_domain_model_contract
    SET function_type = 0 WHERE function_type IS NULL;
UPDATE tx_academicpersons_domain_model_contract
    SET location = 0 WHERE location IS NULL;

An empty relation is stored as 0 from now on; Extbase resolves both NULL and 0 to an unset relation, so rendering is unaffected.

Affected Installations 

Every installation — the schema change applies everywhere. Functionally broken before this change: PostgreSQL installations only.