column.setPreferredWidth(130);
} else if (MetadataTableModel.IS_KEY_FIELD_INDEX == i) {// isKey
column.setPreferredWidth(70);
} else if (MetadataTableModel.CONSTRAINT_TYPE_INDEX == i) {// keyType
JComboBox constraintTypeComboBox = new JComboBox(new ConstraintTypeComboBoxModel());
constraintTypeComboBox.addItemListener(new ConstraintTypeComboBoxItemListener(this));
column.setCellEditor(new DefaultCellEditor(constraintTypeComboBox));
column.setPreferredWidth(250);
} else if (MetadataTableModel.REFERENCING_TABLE_INDEX == i) {// ReferencingTable
JComboBox referencingTableComboBox = new JComboBox();
referencingTableComboBox.addPopupMenuListener(new TableComboBoxPopupMenuListener(this));