/*
* JEF - Copyright 2009-2010 Jiyi (mr.jiyi@gmail.com)
*
* Licensed 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 jef.database.wrapper.clause;
import java.util.List;
import jef.database.ORMConfig;
import jef.database.cache.CacheImpl;
import jef.database.cache.CacheKey;
import jef.database.cache.KeyDimension;
import jef.database.cache.SqlCacheKey;
import jef.database.dialect.DatabaseDialect;
import jef.database.jdbc.result.ResultSetContainer;
import jef.database.jdbc.statement.ResultSetLaterProcess;
import jef.database.routing.PartitionResult;
import jef.database.routing.sql.SqlAnalyzer;
import jef.database.wrapper.variable.Variable;
import jef.tools.Assert;
import jef.tools.PageLimit;
/**
* 必要Part五部分， 4+1
*
* @author Administrator
*
*/
public class QueryClauseImpl implements QueryClause {
/*
* 这两部分总是只有一个有值 当单表查询时支持分表，所以是PartitionResult 当多表关联时，目前不支持分表，所以是string
*/
private String tableDefinition;
private PartitionResult[] tables = P;
public static final QueryClauseImpl EMPTY = new QueryClauseImpl(new PartitionResult[0]);
// //是否为union
// private boolean isUnion = false;
// Select部分
private SelectPart selectPart;
// Where
private String wherePart;
// groupBy
private GroupClause grouphavingPart;// =GroupClause.DEFAULT
// 排序
private OrderClause orderbyPart = OrderClause.DEFAULT;
// 绑定变量
private List<Variable> bind;
// 范围
private PageLimit pageRange;
private DatabaseDialect profile;
public QueryClauseImpl(DatabaseDialect profile) {
this.profile = profile;
}
private QueryClauseImpl(PartitionResult[] partitionResults) {
this.tables = partitionResults;
}
public PageLimit getPageRange() {
return pageRange;
}
public void setPageRange(PageLimit pageRange) {
this.pageRange = pageRange;
}
public OrderClause getOrderbyPart() {
return orderbyPart;
}
public void setOrderbyPart(OrderClause orderbyPart) {
this.orderbyPart = orderbyPart;
}
public GroupClause getGrouphavingPart() {
return grouphavingPart;
}
public void setGrouphavingPart(GroupClause grouphavingPart) {
this.grouphavingPart = grouphavingPart;
}
public SelectPart getSelectPart() {
return selectPart;
}
public void setSelectPart(SelectPart selectPart) {
this.selectPart = selectPart;
}
public String getWherePart() {
return wherePart;
}
public void setWherePart(String wherePart) {
this.wherePart = wherePart;
}
public String getTableDefinition() {
return tableDefinition;
}
public void setTableDefinition(String tableDefinition) {
this.tableDefinition = tableDefinition;
}
public void setBind(List<Variable> bind) {
this.bind = bind;
}
public PartitionResult[] getTables() {
return tables;
}
public void setTables(String baseTableName,PartitionResult[] tables) {
this.baseTableName = baseTableName;
this.tables = tables;
}
@Override
public String toString() {
return String.valueOf(getSql(null));
}
/*
*
* @param tableDef
*
* @param delayProcessGroupClause 说明是在union字句中，需要确保是先把unionall 再groupby
*
* @return
*/
private String getSql(String tableDef, boolean delayProcessGroupClause) {
StringBuilder sb = new StringBuilder(200);
if(delayProcessGroupClause){
selectPart.appendNoGroupFunc(sb);
}else{
selectPart.append(sb);
}
sb.append(" from ");
sb.append(tableDef);
if (wherePart.length() > 0) {
sb.append(ORMConfig.getInstance().wrap);
sb.append(wherePart);
}
if (!delayProcessGroupClause)
sb.append(grouphavingPart);
return sb.toString();
}
public BindSql getSql(PartitionResult site) {
if (tableDefinition != null) {
return withPage(getSql(tableDefinition, false).concat(orderbyPart.getSql()), false).setBind(bind);
}
if (site == null) {
if (tables.length == 0) {
throw new IllegalArgumentException("The partition result does not return any result!");
}
site = this.tables[0];
}
StringBuilder sb = new StringBuilder(200);
List<Variable> bind = this.bind;
boolean moreTable = site.tableSize() > 1;
for (int i = 0; i < site.tableSize(); i++) {
if (i > 0) {
sb.append("\n union all \n");
}
String tableName = site.getTablesEscaped(profile).get(i);
sb.append(getSql(tableName.concat(" t"), moreTable && grouphavingPart.isNotEmpty()));// 为多表、并且有groupby时需要特殊处理.grouphavingPart.isNotEmpty()不能省略。
//如果省略掉，则多表union时造成所有内部表的字段均未使用别名。此时外部又没有套一层将列转为别名，最终效果是别名无效。
}
// 不带group by、having、order by从句的情况下，无需再union一层，
// 否则，对查询列指定别名时会产生异常。
if (moreTable && (grouphavingPart.isNotEmpty() || orderbyPart.isNotEmpty())) {
StringBuilder sb2 = new StringBuilder();
selectPart.append(sb2);
sb2.append(" from (").append(sb).append(") t");
sb2.append(ORMConfig.getInstance().wrap);
sb2.append(grouphavingPart.getSql(false));
sb = sb2;
}
if (moreTable) {
// 当复杂情况下，绑定变量也要翻倍
bind = SqlAnalyzer.repeat(this.bind, site.tableSize());
}
sb.append(orderbyPart.getSql());
return withPage(sb.toString(), moreTable).setBind(bind);
}
private BindSql withPage(String sql, boolean union) {
if (pageRange != null) {
if(isMultiDatabase()){
if(grouphavingPart==null || !grouphavingPart.isNotEmpty()){
return profile.getLimitHandler().toPageSQL(sql, new int[]{0,pageRange.getEndAsInt()}, union);
}
}else{
return profile.getLimitHandler().toPageSQL(sql, pageRange.toArray(), union);
}
}
return new BindSql(sql);
}
private CacheKey cacheKey;
private String baseTableName;
public CacheKey getCacheKey() {
if (cacheKey != null)
return cacheKey;
try{
if(baseTableName == null) {
this.cacheKey=new SqlCacheKey(new KeyDimension(tableDefinition,wherePart, orderbyPart.getSql(),profile), CacheImpl.toParamList(this.bind));
}else {
this.cacheKey=new SqlCacheKey(KeyDimension.forSingleTable(baseTableName,wherePart, orderbyPart.getSql(),profile), CacheImpl.toParamList(this.bind));
}
return cacheKey;
}catch(RuntimeException e){
return null;
}
}
public boolean isEmpty() {
return this.tables != null && tables.length == 0;
}
public boolean isMultiDatabase() {
return this.tables != null && tables.length > 1;
}
public boolean isDistinct() {
return selectPart.isDistinct();
}
@Override
public boolean hasInMemoryOperate() {
return isMultiDatabase();
}
@Override
public void parepareInMemoryProcess(PageLimit range, ResultSetContainer rs) {
if (getOrderbyPart().isNotEmpty()) {
rs.setInMemoryOrder(getOrderbyPart().parseAsSelectOrder(getSelectPart(), rs.getColumns()));
}
if (getGrouphavingPart().isNotEmpty()) {
rs.setInMemoryGroups(getGrouphavingPart().parseSelectFunction(getSelectPart()));
}
if (isDistinct()) {
rs.setInMemoryDistinct(InMemoryDistinct.instance);
}
Assert.isNull(range);
if (this.pageRange != null) {
rs.setInMemoryPage(new InMemoryPaging(this.pageRange));
}
}
@Override
public ResultSetLaterProcess getRsLaterProcessor() {
return null;
}
}