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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.cayenne.map;
import org.apache.cayenne.dba.TypesMapping;
import org.apache.cayenne.map.event.AttributeEvent;
import org.apache.cayenne.map.event.DbAttributeListener;
import org.apache.cayenne.util.Util;
import org.apache.cayenne.util.XMLEncoder;
/**
* A DbAttribute defines a descriptor for a single database table column.
*
* @author Misha Shengaout
* @author Andrus Adamchik
*/
public class DbAttribute extends Attribute {
/**
* Defines JDBC type of the column.
*/
protected int type = TypesMapping.NOT_DEFINED;
/**
* Defines whether the attribute allows nulls.
*/
protected boolean mandatory;
/**
* Defines whether the attribute is a part of the table primary key.
*/
protected boolean primaryKey;
/**
* Defines whether this column value is generated by the database. Other terms for
* such columns are "auto-increment" or "identity".
*
* @since 1.2
*/
protected boolean generated;
// The length of CHAR or VARCHAr or max num of digits for DECIMAL.
protected int maxLength = -1;
/**
* @since 3.0
*/
protected int scale = -1;
/**
* @since 3.0
*/
// must call it 'attributePrecison' as 'precision' in 1.2 really meant 'scale'
protected int attributePrecision = -1;
public DbAttribute() {
super();
}
public DbAttribute(String name) {
super(name);
}
public DbAttribute(String name, int type, DbEntity entity) {
this.setName(name);
this.setType(type);
this.setEntity(entity);
}
/**
* Prints itself as XML to the provided XMLEncoder.
*
* @since 1.1
*/
@Override
public void encodeAsXML(XMLEncoder encoder) {
encoder.print("<db-attribute name=\"");
encoder.print(Util.encodeXmlAttribute(getName()));
encoder.print('\"');
String type = TypesMapping.getSqlNameByType(getType());
if (type != null) {
encoder.print(" type=\"" + type + '\"');
}
if (isPrimaryKey()) {
encoder.print(" isPrimaryKey=\"true\"");
// only allow generated if an attribute is a PK.
if (isGenerated()) {
encoder.print(" isGenerated=\"true\"");
}
}
if (isMandatory()) {
encoder.print(" isMandatory=\"true\"");
}
if (getMaxLength() > 0) {
encoder.print(" length=\"");
encoder.print(getMaxLength());
encoder.print('\"');
}
if (getScale() > 0) {
encoder.print(" scale=\"");
encoder.print(getScale());
encoder.print('\"');
}
if (getAttributePrecision() > 0) {
encoder.print(" attributePrecision=\"");
encoder.print(getAttributePrecision());
encoder.print('\"');
}
encoder.println("/>");
}
public String getAliasedName(String alias) {
return (alias != null) ? alias + '.' + this.getName() : this.getName();
}
/**
* Returns the SQL type of the column.
*
* @see java.sql.Types
*/
public int getType() {
return type;
}
/**
* Sets the SQL type for the column.
*
* @see java.sql.Types
*/
public void setType(int type) {
this.type = type;
}
public boolean isPrimaryKey() {
return primaryKey;
}
/**
* Returns <code>true</code> if the DB column represented by this attribute is a
* foreign key, referencing another table.
*
* @since 1.1
*/
public boolean isForeignKey() {
String name = getName();
if (name == null) {
// won't be able to match joins...
return false;
}
for (Relationship relationship : getEntity().getRelationships()) {
for (DbJoin join : ((DbRelationship)relationship).getJoins()) {
if (name.equals(join.getSourceName())) {
DbAttribute target = join.getTarget();
if (target != null && target.isPrimaryKey()) {
return true;
}
}
}
}
return false;
}
/**
* Updates attribute "primaryKey" property.
*/
public void setPrimaryKey(boolean primaryKey) {
if (this.primaryKey != primaryKey) {
this.primaryKey = primaryKey;
Entity e = this.getEntity();
if (e instanceof DbAttributeListener) {
((DbAttributeListener) e).dbAttributeChanged(new AttributeEvent(
this,
this,
e));
}
}
}
public boolean isMandatory() {
return mandatory;
}
public void setMandatory(boolean mandatory) {
this.mandatory = mandatory;
}
/**
* Returns the length of database column described by this attribute.
*/
public int getMaxLength() {
return maxLength;
}
/**
* Sets the length of character or binary type or max num of digits for DECIMAL.
*/
public void setMaxLength(int maxLength) {
this.maxLength = maxLength;
}
/**
* Returns the number of digits after period for DECIMAL.
*
* @deprecated since 3.0 as this property really referred to 'scale'. Use
* {@link #getScale()} instead.
*/
public int getPrecision() {
return getScale();
}
/**
* @deprecated since 3.0 as this property really referred to 'scale'. Use
* {@link #setScale(int)} instead.
*/
public void setPrecision(int i) {
setScale(i);
}
/**
* Returns true if this column value is generated by the database. Other terms for
* such columns are "auto-increment" or "identity".
*
* @since 1.2
*/
public boolean isGenerated() {
return generated;
}
/**
* Updates attribute "generated" property.
*
* @since 1.2
*/
public void setGenerated(boolean generated) {
if (this.generated != generated) {
this.generated = generated;
Entity e = this.getEntity();
if (e instanceof DbAttributeListener) {
((DbAttributeListener) e).dbAttributeChanged(new AttributeEvent(
this,
this,
e));
}
}
}
/**
* @since 3.0
*/
public int getAttributePrecision() {
return attributePrecision;
}
/**
* @since 3.0
*/
public void setAttributePrecision(int attributePrecision) {
this.attributePrecision = attributePrecision;
}
/**
* Returns the number of digits after period for decimal attributes. Returns "-1" if
* not set.
*
* @since 3.0
*/
public int getScale() {
return scale;
}
/**
* @since 3.0
*/
public void setScale(int scale) {
this.scale = scale;
}
}