svn-gvsig-desktop / trunk / org.gvsig.desktop / org.gvsig.desktop.compat.cdc / org.gvsig.fmap.dal / org.gvsig.fmap.dal.impl / src / main / java / org / gvsig / expressionevaluator / impl / function / dataaccess / SelectCountFunction.java @ 45366
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/**
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* gvSIG. Desktop Geographic Information System.
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*
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* Copyright (C) 2007-2020 gvSIG Association.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 3
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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* MA 02110-1301, USA.
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*
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* For any additional information, do not hesitate to contact us
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* at info AT gvsig.com, or visit our website www.gvsig.com.
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*/
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package org.gvsig.expressionevaluator.impl.function.dataaccess; |
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import org.apache.commons.lang3.Range; |
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import org.gvsig.expressionevaluator.Code; |
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import org.gvsig.expressionevaluator.Codes; |
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import org.gvsig.expressionevaluator.ExpressionRuntimeException; |
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import org.gvsig.expressionevaluator.Interpreter; |
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import org.gvsig.expressionevaluator.impl.DALFunctions; |
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import static org.gvsig.expressionevaluator.impl.function.dataaccess.SelectFunction.removeOuterTablesReferences; |
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import org.gvsig.fmap.dal.DALLocator; |
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import org.gvsig.fmap.dal.DataManager; |
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import static org.gvsig.fmap.dal.DataManager.FUNCTION_SELECT_COUNT; |
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import org.gvsig.fmap.dal.DataStore; |
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import org.gvsig.expressionevaluator.ExpressionEvaluator; |
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import org.gvsig.fmap.dal.feature.FeatureQuery; |
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import org.gvsig.fmap.dal.feature.FeatureSet; |
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import org.gvsig.fmap.dal.feature.FeatureStore; |
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import org.gvsig.fmap.dal.impl.expressionevaluator.DefaultFeatureExpressionEvaluator; |
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import org.gvsig.tools.dispose.DisposeUtils; |
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/**
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*
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* @author jjdelcerro
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*/
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@SuppressWarnings("UseSpecificCatch") |
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public class SelectCountFunction extends AbstractFeatureFunction { |
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public SelectCountFunction() {
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super(DALFunctions.GROUP_DATA_ACCESS,
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FUNCTION_SELECT_COUNT, |
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Range.between(1,2), |
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"Returns the number of features of the table by applying the filter indicated.\n" +
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"The syntax is:\n\n"+
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"SELECT COUNT(*) FROM table WHERE boolean_expression;\n\n"+
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"Indicate a filter expression with WHERE is optional.\n"+
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"The SELECT statement must always end with a semicolon.",
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"SELECT COUNT(*) FROM {{table}} WHERE filter ;",
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new String[]{ |
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"table - Name of the table",
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"filter - boolean expression with the filter to apply",
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}, |
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"Long",
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false
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); |
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} |
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@Override
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public boolean isHidden() { |
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return false; |
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} |
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@Override
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public boolean allowConstantFolding() { |
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return false; |
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} |
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@Override
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public boolean useArgumentsInsteadObjects() { |
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return true; |
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} |
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@Override
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public Object call(Interpreter interpreter, Object[] args) throws Exception { |
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throw new UnsupportedOperationException(); |
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} |
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@Override
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public Object call(Interpreter interpreter, Codes args) throws Exception { |
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String storeName = (String) getObject(interpreter, args, 0); |
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Code where = args.get(1);
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if( where.code()==Code.CONSTANT ) {
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if( ((Code.Constant)where).value()==null ) { |
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where = null;
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} |
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} |
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FeatureStore featureStore = null;
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FeatureSet set = null;
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try {
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DataStore store = this.getStore(storeName);
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if (store == null ) { |
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throw new ExpressionRuntimeException("Cant locate the store '" + storeName + "' in function '" + FUNCTION_SELECT_COUNT + "'."); |
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} |
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if (!(store instanceof FeatureStore)) { |
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throw new ExpressionRuntimeException("The store'" + storeName + "' is not valid for function '" + FUNCTION_SELECT_COUNT + "', a FeatureStore is required."); |
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} |
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featureStore = (FeatureStore) store; |
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if (where == null ) { |
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set = featureStore.getFeatureSet(); |
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} else {
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FeatureQuery query = featureStore.createFeatureQuery(); |
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Code where2 = removeOuterTablesReferences(interpreter, where); |
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ExpressionEvaluator filter = new DefaultFeatureExpressionEvaluator(where2.toString());
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filter.toSymbolTable().addSymbolTable(interpreter.getSymbolTable()); |
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query.addFilter(filter); |
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query.retrievesAllAttributes(); |
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set = featureStore.getFeatureSet(query); |
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} |
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return set.getSize();
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} catch (ExpressionRuntimeException ex) {
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throw ex;
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} catch (Exception ex) { |
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throw new ExpressionRuntimeException("Problems calling '" + FUNCTION_SELECT_COUNT + "' function", ex); |
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} finally {
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DisposeUtils.disposeQuietly(set); |
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DisposeUtils.disposeQuietly(featureStore); |
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} |
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} |
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protected DataStore getStore(String storeName) { |
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DataManager dataManager = DALLocator.getDataManager(); |
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DataStore store = dataManager.getStoresRepository().getStore(storeName); |
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return store;
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} |
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} |