com.avaje.ebeaninternal.server.query.CQueryBuilder 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.query;
import java.util.Iterator;
import java.util.Set;
import javax.persistence.PersistenceException;
import com.avaje.ebean.BackgroundExecutor;
import com.avaje.ebean.RawSql;
import com.avaje.ebean.RawSql.ColumnMapping;
import com.avaje.ebean.RawSql.ColumnMapping.Column;
import com.avaje.ebean.RawSqlBuilder;
import com.avaje.ebean.config.GlobalProperties;
import com.avaje.ebean.config.dbplatform.DatabasePlatform;
import com.avaje.ebean.config.dbplatform.SqlLimitRequest;
import com.avaje.ebean.config.dbplatform.SqlLimitResponse;
import com.avaje.ebean.config.dbplatform.SqlLimiter;
import com.avaje.ebean.text.PathProperties;
import com.avaje.ebeaninternal.api.SpiQuery;
import com.avaje.ebeaninternal.server.core.OrmQueryRequest;
import com.avaje.ebeaninternal.server.deploy.BeanDescriptor;
import com.avaje.ebeaninternal.server.deploy.BeanProperty;
import com.avaje.ebeaninternal.server.deploy.BeanPropertyAssocMany;
import com.avaje.ebeaninternal.server.deploy.BeanPropertyAssocOne;
import com.avaje.ebeaninternal.server.el.ElPropertyValue;
import com.avaje.ebeaninternal.server.persist.Binder;
import com.avaje.ebeaninternal.server.querydefn.OrmQueryDetail;
import com.avaje.ebeaninternal.server.querydefn.OrmQueryLimitRequest;
/**
* Generates the SQL SELECT statements taking into account the physical
* deployment properties.
*/
public class CQueryBuilder implements Constants {
private final String tableAliasPlaceHolder;
private final String columnAliasPrefix;
private final SqlLimiter sqlLimiter;
private final RawSqlSelectClauseBuilder sqlSelectBuilder;
private final CQueryBuilderRawSql rawSqlHandler;
private final Binder binder;
private final BackgroundExecutor backgroundExecutor;
private final boolean selectCountWithAlias;
private DatabasePlatform dbPlatform;
/**
* Create the SqlGenSelect.
*/
public CQueryBuilder(BackgroundExecutor backgroundExecutor, DatabasePlatform dbPlatform, Binder binder) {
this.backgroundExecutor = backgroundExecutor;
this.binder = binder;
this.tableAliasPlaceHolder = GlobalProperties.get("ebean.tableAliasPlaceHolder", "${ta}");
this.columnAliasPrefix = GlobalProperties.get("ebean.columnAliasPrefix", "c");
this.sqlSelectBuilder = new RawSqlSelectClauseBuilder(dbPlatform, binder);
this.sqlLimiter = dbPlatform.getSqlLimiter();
this.rawSqlHandler = new CQueryBuilderRawSql(sqlLimiter, dbPlatform);
this.selectCountWithAlias = dbPlatform.isSelectCountWithAlias();
this.dbPlatform = dbPlatform;
}
/**
* split the order by claus on the field delimiter and prefix each field with
* the relation name
*/
public static String prefixOrderByFields(String name, String orderBy) {
StringBuilder sb = new StringBuilder();
for (String token : orderBy.split(",")) {
if (sb.length() > 0) {
sb.append(", ");
}
sb.append(name);
sb.append(".");
sb.append(token.trim());
}
return sb.toString();
}
/**
* Build the row count query.
*/
public CQueryFetchIds buildFetchIdsQuery(OrmQueryRequest request) {
SpiQuery query = request.getQuery();
query.setSelectId();
CQueryPredicates predicates = new CQueryPredicates(binder, request);
CQueryPlan queryPlan = request.getQueryPlan();
if (queryPlan != null) {
// skip building the SqlTree and Sql string
predicates.prepare(false);
String sql = queryPlan.getSql();
return new CQueryFetchIds(request, predicates, sql, backgroundExecutor);
}
// use RawSql or generated Sql
predicates.prepare(true);
SqlTree sqlTree = createSqlTree(request, predicates);
SqlLimitResponse s = buildSql(null, request, predicates, sqlTree);
String sql = s.getSql();
// cache the query plan
queryPlan = new CQueryPlan(sql, sqlTree, false, s.isIncludesRowNumberColumn(), predicates.getLogWhereSql());
request.putQueryPlan(queryPlan);
return new CQueryFetchIds(request, predicates, sql, backgroundExecutor);
}
/**
* Build the row count query.
*/
public CQueryRowCount buildRowCountQuery(OrmQueryRequest request) {
SpiQuery query = request.getQuery();
// always set the order by to null for row count query
query.setOrder(null);
boolean hasMany = !query.getManyWhereJoins().isEmpty();
query.setSelectId();
String sqlSelect = "select count(*)";
if (hasMany) {
// need to count distinct id's ...
query.setDistinct(true);
sqlSelect = null;
}
CQueryPredicates predicates = new CQueryPredicates(binder, request);
CQueryPlan queryPlan = request.getQueryPlan();
if (queryPlan != null) {
// skip building the SqlTree and Sql string
predicates.prepare(false);
String sql = queryPlan.getSql();
return new CQueryRowCount(request, predicates, sql);
}
predicates.prepare(true);
SqlTree sqlTree = createSqlTree(request, predicates);
SqlLimitResponse s = buildSql(sqlSelect, request, predicates, sqlTree);
String sql = s.getSql();
if (hasMany) {
sql = "select count(*) from ( " + sql + ")";
if (selectCountWithAlias) {
sql += " as c";
}
}
// cache the query plan
queryPlan = new CQueryPlan(sql, sqlTree, false, s.isIncludesRowNumberColumn(), predicates.getLogWhereSql());
request.putQueryPlan(queryPlan);
return new CQueryRowCount(request, predicates, sql);
}
/**
* Return the SQL Select statement as a String. Converts logical property
* names to physical deployment column names.
*/
public CQuery buildQuery(OrmQueryRequest request) {
if (request.isSqlSelect()) {
return sqlSelectBuilder.build(request);
}
CQueryPredicates predicates = new CQueryPredicates(binder, request);
CQueryPlan queryPlan = request.getQueryPlan();
if (queryPlan != null) {
// Reuse the query plan so skip generating SqlTree and SQL.
// We do prepare and bind the new parameters
predicates.prepare(false);
return new CQuery(request, predicates, queryPlan);
}
// RawSql or Generated Sql query
// Prepare the where, having and order by clauses.
// This also parses them from logical property names to
// database columns and determines 'includes'.
// We need to check these 'includes' for extra joins
// that are not included via select
predicates.prepare(true);
// Build the tree structure that represents the query.
SqlTree sqlTree = createSqlTree(request, predicates);
SqlLimitResponse res = buildSql(null, request, predicates, sqlTree);
boolean rawSql = request.isRawSql();
if (rawSql) {
queryPlan = new CQueryPlanRawSql(request, res, sqlTree, predicates.getLogWhereSql());
} else {
queryPlan = new CQueryPlan(request, res, sqlTree, rawSql, predicates.getLogWhereSql(), null);
}
// cache the query plan because we can reuse it and also
// gather query performance statistics based on it.
request.putQueryPlan(queryPlan);
return new CQuery(request, predicates, queryPlan);
}
/**
* Build the SqlTree.
*
* The SqlTree is immutable after construction and so is safe to use by
* concurrent threads.
*
*
* The predicates is used to add additional joins that come from the where or
* order by clauses that are not already included for the select clause.
*
*/
private SqlTree createSqlTree(OrmQueryRequest request, CQueryPredicates predicates) {
if (request.isRawSql()) {
return createRawSqlSqlTree(request, predicates);
}
return new SqlTreeBuilder(tableAliasPlaceHolder, columnAliasPrefix, request, predicates).build();
}
private SqlTree createRawSqlSqlTree(OrmQueryRequest request, CQueryPredicates predicates) {
BeanDescriptor descriptor = request.getBeanDescriptor();
ColumnMapping columnMapping = request.getQuery().getRawSql().getColumnMapping();
PathProperties pathProps = new PathProperties();
// convert list of columns into (tree like) PathProperties
Iterator it = columnMapping.getColumns();
while (it.hasNext()) {
RawSql.ColumnMapping.Column column = it.next();
String propertyName = column.getPropertyName();
if (!RawSqlBuilder.IGNORE_COLUMN.equals(propertyName)) {
ElPropertyValue el = descriptor.getElGetValue(propertyName);
if (el == null) {
String msg = "Property [" + propertyName + "] not found on " + descriptor.getFullName();
throw new PersistenceException(msg);
}
BeanProperty beanProperty = el.getBeanProperty();
if (beanProperty.isId()) {
// For @Id properties we chop off the last part of the path
propertyName = SplitName.parent(propertyName);
} else if (beanProperty instanceof BeanPropertyAssocOne) {
String msg = "Column [" + column.getDbColumn() + "] mapped to complex Property[" + propertyName + "]";
msg += ". It should be mapped to a simple property (proably the Id property). ";
throw new PersistenceException(msg);
}
if (propertyName != null) {
String[] pathProp = SplitName.split(propertyName);
pathProps.addToPath(pathProp[0], pathProp[1]);
}
}
}
OrmQueryDetail detail = new OrmQueryDetail();
// transfer PathProperties into OrmQueryDetail
Iterator pathIt = pathProps.getPaths().iterator();
while (pathIt.hasNext()) {
String path = pathIt.next();
Set props = pathProps.get(path);
detail.getChunk(path, true).setDefaultProperties(null, props);
}
// build SqlTree based on OrmQueryDetail of the RawSql
return new SqlTreeBuilder(request, predicates, detail).build();
}
private SqlLimitResponse buildSql(String selectClause, OrmQueryRequest request, CQueryPredicates predicates, SqlTree select) {
SpiQuery query = request.getQuery();
RawSql rawSql = query.getRawSql();
if (rawSql != null) {
return rawSqlHandler.buildSql(request, predicates, rawSql.getSql());
}
BeanPropertyAssocMany manyProp = select.getManyProperty();
boolean useSqlLimiter = false;
StringBuilder sb = new StringBuilder(500);
if (selectClause != null) {
sb.append(selectClause);
} else {
useSqlLimiter = (query.hasMaxRowsOrFirstRow() && manyProp == null);
if (!useSqlLimiter) {
sb.append("select ");
if (query.isDistinct()) {
sb.append("distinct ");
}
}
sb.append(select.getSelectSql());
}
sb.append(" ").append(NEW_LINE);
sb.append("from ");
// build the from clause potentially with joins
// required only for the predicates
sb.append(select.getFromSql());
String inheritanceWhere = select.getInheritanceWhereSql();
boolean hasWhere = false;
if (inheritanceWhere.length() > 0) {
sb.append(" ").append(NEW_LINE).append("where");
sb.append(inheritanceWhere);
hasWhere = true;
}
if (request.isFindById() || query.getId() != null) {
if (hasWhere) {
sb.append(" and ");
} else {
sb.append(NEW_LINE).append("where ");
}
BeanDescriptor desc = request.getBeanDescriptor();
String idSql = desc.getIdBinderIdSql();
if (idSql.isEmpty()) {
throw new IllegalStateException("Executing FindById query on entity bean " + desc.getName()
+ " that doesn't have an @Id property??");
}
sb.append(idSql).append(" ");
hasWhere = true;
}
String dbWhere = predicates.getDbWhere();
if (!isEmpty(dbWhere)) {
if (!hasWhere) {
hasWhere = true;
sb.append(" ").append(NEW_LINE).append("where ");
} else {
sb.append("and ");
}
sb.append(dbWhere);
}
String dbFilterMany = predicates.getDbFilterMany();
if (!isEmpty(dbFilterMany)) {
if (!hasWhere) {
sb.append(" ").append(NEW_LINE).append("where ");
} else {
sb.append("and ");
}
sb.append(dbFilterMany);
}
String dbOrderBy = predicates.getDbOrderBy();
if (dbOrderBy != null) {
sb.append(" ").append(NEW_LINE);
sb.append("order by ").append(dbOrderBy);
}
if (useSqlLimiter) {
// use LIMIT/OFFSET, ROW_NUMBER() or rownum type SQL query limitation
SqlLimitRequest r = new OrmQueryLimitRequest(sb.toString(), dbOrderBy, query, dbPlatform);
return sqlLimiter.limit(r);
} else {
return new SqlLimitResponse(dbPlatform.completeSql(sb.toString(), query), false);
}
}
private boolean isEmpty(String s) {
return s == null || s.length() == 0;
}
}