package org.h2.command.ddl;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
import org.h2.api.ErrorCode;
import org.h2.command.CommandInterface;
import org.h2.constraint.Constraint;
import org.h2.constraint.ConstraintActionType;
import org.h2.engine.Database;
import org.h2.engine.Right;
import org.h2.engine.Session;
import org.h2.message.DbException;
import org.h2.schema.Schema;
import org.h2.table.Table;
import org.h2.table.TableView;
import org.h2.util.StringUtils;
public class DropTable extends SchemaCommand {
private boolean ifExists;
private String tableName;
private Table table;
private DropTable next;
private ConstraintActionType dropAction;
public DropTable(Session session, Schema schema) {
super(session, schema);
dropAction = session.getDatabase().getSettings().dropRestrict ?
ConstraintActionType.RESTRICT :
ConstraintActionType.CASCADE;
}
public void addNextDropTable(DropTable drop) {
if (next == null) {
next = drop;
} else {
next.addNextDropTable(drop);
}
}
public void setIfExists(boolean b) {
ifExists = b;
if (next != null) {
next.setIfExists(b);
}
}
public void setTableName(String tableName) {
this.tableName = tableName;
}
private void prepareDrop() {
table = getSchema().findTableOrView(session, tableName);
if (table == null) {
if (!ifExists) {
throw DbException.get(ErrorCode.TABLE_OR_VIEW_NOT_FOUND_1, tableName);
}
} else {
session.getUser().checkRight(table, Right.ALL);
if (!table.canDrop()) {
throw DbException.get(ErrorCode.CANNOT_DROP_TABLE_1, tableName);
}
if (dropAction == ConstraintActionType.RESTRICT) {
ArrayList<String> dependencies = new ArrayList<>();
CopyOnWriteArrayList<TableView> dependentViews = table.getDependentViews();
if (dependentViews != null && !dependentViews.isEmpty()) {
for (TableView v : dependentViews) {
dependencies.add(v.getName());
}
}
if (session.getDatabase()
.getSettings().standardDropTableRestrict) {
final List<Constraint> constraints = table.getConstraints();
if (constraints != null && !constraints.isEmpty()) {
for (Constraint c : constraints) {
if (c.getTable() != table) {
dependencies.add(c.getName());
}
}
}
}
if (!dependencies.isEmpty()) {
throw DbException.get(ErrorCode.CANNOT_DROP_2, tableName,
StringUtils.join(new StringBuilder(), dependencies, ", ").toString());
}
}
table.lock(session, true, true);
}
if (next != null) {
next.prepareDrop();
}
}
private void executeDrop() {
table = getSchema().findTableOrView(session, tableName);
if (table != null) {
table.setModified();
Database db = session.getDatabase();
db.lockMeta(session);
db.removeSchemaObject(session, table);
}
if (next != null) {
next.executeDrop();
}
}
@Override
public int update() {
session.commit(true);
prepareDrop();
executeDrop();
return 0;
}
public void setDropAction(ConstraintActionType dropAction) {
this.dropAction = dropAction;
if (next != null) {
next.setDropAction(dropAction);
}
}
@Override
public int getType() {
return CommandInterface.DROP_TABLE;
}
}