org.h2.command.ddl.DropDatabase Maven / Gradle / Ivy
/*
* Copyright 2004-2019 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (https://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.command.ddl;
import java.util.ArrayList;
import org.h2.command.CommandInterface;
import org.h2.engine.Database;
import org.h2.engine.DbObject;
import org.h2.engine.Role;
import org.h2.engine.Session;
import org.h2.engine.User;
import org.h2.schema.Schema;
import org.h2.schema.SchemaObject;
import org.h2.schema.Sequence;
import org.h2.table.Table;
import org.h2.table.TableType;
/**
* This class represents the statement
* DROP ALL OBJECTS
*/
public class DropDatabase extends DefineCommand {
private boolean dropAllObjects;
private boolean deleteFiles;
public DropDatabase(Session session) {
super(session);
}
@Override
public int update() {
if (dropAllObjects) {
dropAllObjects();
}
if (deleteFiles) {
session.getDatabase().setDeleteFilesOnDisconnect(true);
}
return 0;
}
private void dropAllObjects() {
session.getUser().checkAdmin();
session.commit(true);
Database db = session.getDatabase();
db.lockMeta(session);
// There can be dependencies between tables e.g. using computed columns,
// so we might need to loop over them multiple times.
boolean runLoopAgain;
do {
ArrayList tables = db.getAllTablesAndViews(false);
ArrayList toRemove = new ArrayList<>(tables.size());
for (Table t : tables) {
if (t.getName() != null &&
TableType.VIEW == t.getTableType()) {
toRemove.add(t);
}
}
for (Table t : tables) {
if (t.getName() != null &&
TableType.TABLE_LINK == t.getTableType()) {
toRemove.add(t);
}
}
for (Table t : tables) {
if (t.getName() != null &&
TableType.TABLE == t.getTableType() &&
!t.isHidden()) {
toRemove.add(t);
}
}
for (Table t : tables) {
if (t.getName() != null &&
TableType.EXTERNAL_TABLE_ENGINE == t.getTableType() &&
!t.isHidden()) {
toRemove.add(t);
}
}
runLoopAgain = false;
for (Table t : toRemove) {
if (t.getName() == null) {
// ignore, already dead
} else if (db.getDependentTable(t, t) == null) {
db.removeSchemaObject(session, t);
} else {
runLoopAgain = true;
}
}
} while (runLoopAgain);
// TODO session-local temp tables are not removed
for (Schema schema : db.getAllSchemas()) {
if (schema.canDrop()) {
db.removeDatabaseObject(session, schema);
}
}
ArrayList list = new ArrayList<>();
for (SchemaObject obj : db.getAllSchemaObjects(DbObject.SEQUENCE)) {
// ignore these. the ones we want to drop will get dropped when we
// drop their associated tables, and we will ignore the problematic
// ones that belong to session-local temp tables.
if (!((Sequence) obj).getBelongsToTable()) {
list.add(obj);
}
}
// maybe constraints and triggers on system tables will be allowed in
// the future
list.addAll(db.getAllSchemaObjects(DbObject.CONSTRAINT));
list.addAll(db.getAllSchemaObjects(DbObject.TRIGGER));
list.addAll(db.getAllSchemaObjects(DbObject.CONSTANT));
list.addAll(db.getAllSchemaObjects(DbObject.FUNCTION_ALIAS));
for (SchemaObject obj : list) {
if (obj.isHidden()) {
continue;
}
db.removeSchemaObject(session, obj);
}
for (User user : db.getAllUsers()) {
if (user != session.getUser()) {
db.removeDatabaseObject(session, user);
}
}
for (Role role : db.getAllRoles()) {
String sql = role.getCreateSQL();
// the role PUBLIC must not be dropped
if (sql != null) {
db.removeDatabaseObject(session, role);
}
}
ArrayList dbObjects = new ArrayList<>();
dbObjects.addAll(db.getAllRights());
dbObjects.addAll(db.getAllAggregates());
dbObjects.addAll(db.getAllDomains());
for (DbObject obj : dbObjects) {
String sql = obj.getCreateSQL();
// the role PUBLIC must not be dropped
if (sql != null) {
db.removeDatabaseObject(session, obj);
}
}
}
public void setDropAllObjects(boolean b) {
this.dropAllObjects = b;
}
public void setDeleteFiles(boolean b) {
this.deleteFiles = b;
}
@Override
public int getType() {
return CommandInterface.DROP_ALL_OBJECTS;
}
}
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