public MergerToken createSetAllowNullToDb(DbEntity entity, DbAttribute column) {
return new SetAllowNullToDb(entity, column) {
public List<String> createSql(DbAdapter adapter) {
QuotingStrategy context = adapter.getQuotingStrategy();
String entityName = context.quotedFullyQualifiedName(getEntity()) ;
String columnName = context.quotedName(getColumn());
// Firebird doesn't support ALTER TABLE table_name ALTER column_name DROP NOT NULL
// but this might be achived by modyfication system tables
return Collections.singletonList(String.format("UPDATE RDB$RELATION_FIELDS SET RDB$NULL_FLAG = NULL "+
" WHERE RDB$FIELD_NAME = '%s' AND RDB$RELATION_NAME = '%s'", columnName, entityName));
}