org.apache.empire.db.DBTable Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.empire.db;
// java
import java.lang.reflect.Field;
import java.sql.Connection;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.empire.data.DataMode;
import org.apache.empire.data.DataType;
import org.apache.empire.db.DBRelation.DBCascadeAction;
import org.apache.empire.db.exceptions.NoPrimaryKeyException;
import org.apache.empire.db.exceptions.RecordDeleteFailedException;
import org.apache.empire.db.exceptions.RecordUpdateInvalidException;
import org.apache.empire.exceptions.InvalidArgumentException;
import org.apache.empire.exceptions.ItemExistsException;
import org.apache.empire.exceptions.UnexpectedReturnValueException;
/**
* This class represent one table of the database.
* It contains methods to get, add, update and delete records from the database.
*
*/
public class DBTable extends DBRowSet implements Cloneable
{
// Integer size definitions
public static final int DEFAULT = 0;
public static final int SMALLINT = 2;
public static final int MEDIUMINT = 4;
public static final int BIGINT = 8;
private final static long serialVersionUID = 1L;
private static AtomicInteger tableCount = new AtomicInteger(0);
private final String name;
private String alias;
private final List indexes = new ArrayList();
private Boolean quoteName = null;
private DBCascadeAction cascadeDeleteAction = DBCascadeAction.NONE;
/**
* Construct a new DBTable object set the specified parameters
* to this object and add this object to the current database.
*
* @param name the table name
* @param db the valid database object
*/
public DBTable(String name, DBDatabase db, String alias)
{
super(db);
// generate alias
if (alias==null)
alias = "t" + String.valueOf(tableCount.incrementAndGet());
// init
this.name = name;
this.alias = alias;
// Add Table to Database
if (db != null)
db.addTable(this);
}
/**
* Construct a new DBTable object set the specified parameters
* to this object and add this object to the current database.
*
* @param name the table name
* @param db the valid database object
*/
public DBTable(String name, DBDatabase db)
{
this(name, db, null);
}
/**
* Returns the table name of this object.
*
* @return the table name of this object
*/
@Override
public String getName()
{
return name;
}
/**
* Returns the table alias name of this object.
*
* @return the table alias name of this object
*/
@Override
public String getAlias()
{
return alias;
}
/**
* Returns whether or not the table supports record updates. Default is true.
* @return true if the table allows record updates
*/
@Override
public boolean isUpdateable()
{
return true;
}
/**
* Clones this table and assigns a new table alias.
* This second instance of the same table can be used for self-joins.
*
* This method requires that all declared column fields are NOT declared final.
* i.e. instead of:
*
* public final DBTableColumn MYCOL;
*
* columns must be declared:
*
* public DBTableColumn MYCOL;
*
* A runtime exception for the CloneNotSupported will be thrown if references cannot be adjusted.
*
* Alternatively a second table instance may be created manually like this:
*
* public final MyTable MYTABLE1 = new MyTable();
* public final MyTable MYTABLE2 = new MyTable();
*
* ...
* cmd.join(MYTABLE1.ID, MYTABLE2.PARENTID); // self-join
* ...
*
* @return a table clone with new table alias
*/
@Override
public Object clone() throws CloneNotSupportedException {
try {
DBTable clone = (DBTable) super.clone();
// clone all columns
Class colClass = columns.get(0).getClass();
Class colBase = colClass.getSuperclass();
clone.columns = new ArrayList();
Field[] fields = getClass().getFields();
for (int i = 0; i < columns.size(); i++)
{
DBTableColumn srcCol = (DBTableColumn) columns.get(i);
DBTableColumn newCol = new DBTableColumn(clone, srcCol);
// Replace all references for oldCol to newCol
for (int j = 0; j < fields.length; j++)
{ // Find a class of Type DBColumn or DBTableColumn
Class type = fields[j].getType();
if (type == colClass || type == colBase)
{
try
{ // Check if the field points to the old Value
if (fields[j].get(clone) == srcCol)
fields[j].set(clone, newCol);
} catch (Exception e) {
// IllegalAccessException or IllegalArgumentException
String fieldName = fields[j].getName();
log.error("Cannot adjust declared table field: " + fieldName + ". Reason is: " + e.getMessage());
// throw CloneNotSupportedException
CloneNotSupportedException cnse = new CloneNotSupportedException("Unable to replace field reference for field " + fieldName);
cnse.initCause(e);
throw cnse;
}
}
}
}
// set new alias
clone.alias = "t" + String.valueOf(tableCount.incrementAndGet());
// done
log.info("clone: Table " + name + " cloned! Alias old=" + alias + " new=" + clone.alias);
return clone;
} catch (CloneNotSupportedException e) {
// unable to clone table
log.error("Unable to clone table " + getName());
throw new RuntimeException(e);
}
}
/**
* Adds a column to this table's column list.
*
* @param column a column object
*/
protected void addColumn(DBTableColumn column)
{ // find column by name
if (column==null || column.getRowSet()!=this)
throw new InvalidArgumentException("column", column);
if (getColumn(column.getName())!=null)
throw new ItemExistsException(column.getName());
// add now
columns.add(column);
}
/**
* Creates a new DBTableColumn object and adds it to the column collection.
*
* @param columnName the column name
* @param type the type of the column e.g. integer, text, date
* @param size the column width
* @param dataMode determines whether this column is optional, required or auto-generated
* @param defValue a Object object
* @return the created DBTableColumn object
*/
public final DBTableColumn addColumn(String columnName, DataType type, double size, DataMode dataMode, Object defValue)
{
return new DBTableColumn(this, type, columnName, size, dataMode, defValue);
}
/**
* Creates a new DBTableColumn object and adds it to the column collection.
*
* @param columnName the column name
* @param type the type of the column e.g. integer, text, date
* @param size the column width
* @param dataMode determines whether this column is optional, required or auto-generated
* @return the created DBTableColumn object
*/
public final DBTableColumn addColumn(String columnName, DataType type, double size, DataMode dataMode)
{
return new DBTableColumn(this, type, columnName, size, dataMode, null);
}
/**
* Creates a new DBTableColumn object and adds it to the column collection.
* Instead of the data mode enum, a boolean flag is used to indicate whether the column is required or optional.
*
* @param columnName the column name
* @param type the type of the column e.g. integer, text, date
* @param size the column width
* @param required true if not null column
* @param defValue a Object object
* @return the created DBTableColumn object
*/
public final DBTableColumn addColumn(String columnName, DataType type, double size, boolean required, Object defValue)
{
DataMode dm = (required ? DataMode.NotNull : DataMode.Nullable);
return new DBTableColumn(this, type, columnName, size, dm, defValue);
}
/**
* Creates a new DBTableColumn object and adds it to the column collection.
* Instead of the data mode enum, a boolean flag is used to indicate whether the column is required or optional.
*
* @param columnName the column name
* @param type the type of the column e.g. integer, text, date
* @param size the column width
* @param required true if not null column
* @return the created DBTableColumn object
*/
public final DBTableColumn addColumn(String columnName, DataType type, double size, boolean required)
{
DataMode dm = (required ? DataMode.NotNull : DataMode.Nullable);
return new DBTableColumn(this, type, columnName, size, dm, null);
}
/**
* Returns the primary key.
*
* @return the the DBIndex object -> primary key
*/
public DBIndex getPrimaryKey()
{
return primaryKey;
}
/**
* Returns the list of indexes (except the primary key).
*
* @return a list of DBIndex objects
*/
public List getIndexes()
{
return indexes;
}
/**
* Sets the primary keys.
*
* @param columns a array with one or more DBColumn objects
*/
public void setPrimaryKey(DBColumn... columns)
{
if (columns==null || columns.length==0)
throw new InvalidArgumentException("columns", columns);
// All columns must belong to this table
for (int i=0; i 1)
{ // Multiple Records affected
throw new RecordUpdateInvalidException(this, key);
}
}
/**
* Returns a list of all foreign key relations for this table
* @return the list of foreign key relations
*/
public List getForeignKeyRelations()
{
List relations = new ArrayList();
for (DBRelation r : getDatabase().getRelations())
{ // check relation
if (this.equals(r.getForeignKeyTable()))
relations.add(r);
}
return relations;
}
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