com.avaje.ebeaninternal.server.deploy.TableJoin Maven / Gradle / Ivy
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/**
* Copyright (C) 2006 Robin Bygrave
*
* This file is part of Ebean.
*
* Ebean is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* Ebean is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with Ebean; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package com.avaje.ebeaninternal.server.deploy;
import com.avaje.ebeaninternal.server.core.InternString;
import com.avaje.ebeaninternal.server.deploy.meta.DeployBeanProperty;
import com.avaje.ebeaninternal.server.deploy.meta.DeployTableJoin;
import com.avaje.ebeaninternal.server.deploy.meta.DeployTableJoinColumn;
import com.avaje.ebeaninternal.server.query.SplitName;
import com.avaje.ebeaninternal.server.query.SqlBeanLoad;
import java.sql.SQLException;
import java.util.LinkedHashMap;
/**
* Represents a join to another table.
*/
public final class TableJoin {
public static final String NEW_LINE = "\n";
public static final String LEFT_OUTER = "left outer join";
public static final String JOIN = "join";
/**
* Flag set when the imported key maps to the primary key.
* This occurs for intersection tables (ManyToMany).
*/
private final boolean importedPrimaryKey;
/**
* The joined table.
*/
private final String table;
/**
* The type of join. LEFT OUTER etc.
*/
private final String type;
/**
* The persist cascade info.
*/
private final BeanCascadeInfo cascadeInfo;
/**
* Properties as an array.
*/
private final BeanProperty[] properties;
/**
* Columns as an array.
*/
private final TableJoinColumn[] columns;
/**
* Create a TableJoin.
*/
public TableJoin(DeployTableJoin deploy, LinkedHashMap propMap) {
this.importedPrimaryKey = deploy.isImportedPrimaryKey();
this.table = InternString.intern(deploy.getTable());
this.type = InternString.intern(deploy.getType());
this.cascadeInfo = deploy.getCascadeInfo();
DeployTableJoinColumn[] deployCols = deploy.columns();
this.columns = new TableJoinColumn[deployCols.length];
for (int i = 0; i < deployCols.length; i++) {
this.columns[i] = new TableJoinColumn(deployCols[i]);
}
DeployBeanProperty[] deployProps = deploy.properties();
if (deployProps.length > 0 && propMap == null){
throw new NullPointerException("propMap is null?");
}
this.properties = new BeanProperty[deployProps.length];
for (int i = 0; i < deployProps.length; i++) {
BeanProperty prop = propMap.get(deployProps[i].getName());
this.properties[i] = prop;
}
}
/**
* Create a tableJoin based on this object but with different alias.
*/
public TableJoin createWithAlias(String localAlias, String foreignAlias) {
return new TableJoin(this, localAlias, foreignAlias);
}
/**
* Construct a copy but with different table alias'.
*/
private TableJoin(TableJoin join, String localAlias, String foreignAlias){
// copy the immutable fields
this.importedPrimaryKey = join.importedPrimaryKey;
this.table = join.table;
this.type = join.type;
this.cascadeInfo = join.cascadeInfo;
this.properties = join.properties;
this.columns = join.columns;
}
public String toString() {
StringBuilder sb = new StringBuilder(30);
sb.append(type).append(" ").append(table).append(" ");
for (int i = 0; i < columns.length; i++) {
sb.append(columns[i]).append(" ");
}
return sb.toString();
}
public void appendSelect(DbSqlContext ctx, boolean subQuery) {
for (int i = 0, x = properties.length; i < x; i++) {
properties[i].appendSelect(ctx, subQuery);
}
}
public void load(SqlBeanLoad sqlBeanLoad) throws SQLException {
for (int i = 0, x = properties.length; i < x; i++) {
properties[i].load(sqlBeanLoad);
}
}
public Object readSet(DbReadContext ctx, Object bean, Class type) throws SQLException {
for (int i = 0, x = properties.length; i < x; i++) {
properties[i].readSet(ctx, bean, type);
}
return null;
}
/**
* Return true if the imported foreign key maps to the primary key.
*/
public boolean isImportedPrimaryKey() {
return importedPrimaryKey;
}
/**
* Return the persist info.
*/
public BeanCascadeInfo getCascadeInfo() {
return cascadeInfo;
}
/**
* Return the join columns.
*/
public TableJoinColumn[] columns() {
return columns;
}
/**
* For secondary table joins returns the properties mapped to that table.
*/
public BeanProperty[] properties() {
return properties;
}
/**
* Return the joined table name.
*/
public String getTable() {
return table;
}
/**
* Return the type of join. LEFT OUTER JOIN etc.
*/
public String getType() {
return type;
}
/**
* Return true if this join is a left outer join.
*/
public boolean isOuterJoin() {
return type.equals(LEFT_OUTER);
}
public boolean addJoin(boolean forceOuterJoin, String prefix, DbSqlContext ctx) {
String[] names = SplitName.split(prefix);
String a1 = ctx.getTableAlias(names[0]);
String a2 = ctx.getTableAlias(prefix);
return addJoin(forceOuterJoin, a1, a2, ctx);
}
public boolean addJoin(boolean forceOuterJoin, String a1, String a2, DbSqlContext ctx) {
ctx.addJoin(forceOuterJoin?LEFT_OUTER:type, table, columns(), a1, a2);
return forceOuterJoin || LEFT_OUTER.equals(type);
}
/**
* Explicitly add a (non-outer) join.
*/
public void addInnerJoin(String a1, String a2, DbSqlContext ctx) {
ctx.addJoin(JOIN, table, columns(), a1, a2);
}
}