Source Code Cross Referenced for SearchQuery.java in  » Database-ORM » MMBase » org » mmbase » storage » search » Java Source Code / Java DocumentationJava Source Code and Java Documentation

001:        /*
002:
003:        This software is OSI Certified Open Source Software.
004:        OSI Certified is a certification mark of the Open Source Initiative.
005:
006:        The license (Mozilla version 1.0) can be read at the MMBase site.
007:        See http://www.MMBase.org/license
008:
009:         */
010:        package org.mmbase.storage.search;
011:
012:        import java.util.List;
013:
014:        import org.mmbase.cache.Cacheable;
015:
016:        /**
017:         * Encapsulates a request for a search of the object cloud.
018:         * <p>
019:         * This corresponds to a SELECT query in SQL syntax.
020:         *
021:         * @author Rob van Maris
022:         * @version $Id: SearchQuery.java,v 1.6 2007/12/06 08:13:36 michiel Exp $
023:         * @since MMBase-1.7
024:         */
025:        public interface SearchQuery extends Cacheable {
026:            /**
027:             * Default maxNumber value, corresponds to no maximum.
028:             * @see SearchQuery#getMaxNumber
029:             */
030:            int DEFAULT_MAX_NUMBER = -1;
031:
032:            /**
033:             * Default offset value, corresponds to no offset.
034:             * @see SearchQuery#getOffset
035:             */
036:            int DEFAULT_OFFSET = 0;
037:
038:            /**
039:             * Tests if the search request is to return distinct results. In that case duplicate nodes will be removed from the result.
040:             * <p>
041:             * This corresponds to the use of "DISTINCT" in SQL SELECT-syntax
042:             * .
043:             */
044:            boolean isDistinct();
045:
046:            /**
047:             * Tests if this is an aggregating query, i.e. containing aggregated fields.
048:             */
049:            boolean isAggregating();
050:
051:            /**
052:             * Gets the steps in the search request.
053:             * <p>
054:             * This corresponds to the tables in SQL SELECT-syntax.
055:             */
056:            List<Step> getSteps();
057:
058:            /**
059:             * Gets the stepfields in the search request.
060:             * <p>
061:             * This corresponds to the fields in SQL SELECT-syntax.
062:             */
063:            List<StepField> getFields();
064:
065:            /**
066:             * Gets the constraints on the search results.
067:             * <p>
068:             * This corresponds to (part of) the constraints in the WHERE-clause in SQL SELECT-syntax.
069:             */
070:            Constraint getConstraint();
071:
072:            /**
073:             * Gets the maximum number of results to be returned, or -1 if the number of results to be returned is unlimited.
074:             * <p>
075:             * Note: limiting the number of results may not be supported by the database layer.
076:             */
077:            int getMaxNumber();
078:
079:            /**
080:             * Gets the (zerobased) offset in the list of results, of the first result to return. Note that,
081:             * since it is zerobased, it is equal to the number of results that are skipped.<p> Note:
082:             * skipping results may not be supported by the database layer.
083:             */
084:            int getOffset();
085:
086:            /**
087:             * Gets the SortOrder objects in the order they are to be applied.
088:             *  This specifies the sorting order of the search results.
089:             * <p>
090:             * This corresponds to the ORDER BY clause in SQL SELECT syntax.
091:             */
092:            List<SortOrder> getSortOrders();
093:
094:            /**
095:             * Compares this query to the specified object. The result is
096:             * <code>true</code> if and only if the argument is a non-null
097:             * SearchQuery object representing the same query.
098:             *
099:             * @param obj The object to compare with.
100:             * @return <code>true</code> if the objects are equal,
101:             * <code>false</code> otherwise.
102:             */
103:            public boolean equals(Object obj);
104:
105:            // javadoc is inherited
106:            public int hashCode();
107:
108:            /**
109:             * Returns a string representation of this SearchQuery.
110:             * The string representation has the form
111:             * "SearchQuery(distinct:&lt;distinct&gt;,
112:             *  steps:&lt;steps&gt;, fields:&lt;fields&gt;,
113:             *  constraint:&lt;constraint&gt;, sortorders:&lt;sortorders&gt;,
114:             *  max:&lt;max&gt;, offset:&lt;offset&gt;)"
115:             * where
116:             * <ul>
117:             * <li><em>&lt;distinct&gt;</em> is value returned by
118:             *     {@link #isDistinct isDistinct()}
119:             * <li><em>&lt;steps&gt;</em> is the list returned by
120:             *     {@link #getSteps getSteps()}
121:             * <li><em>&lt;fields&gt;</em> is the list returned by
122:             *     {@link #getFields getFields()}
123:             * <li><em>&lt;constraint&gt;</em> is the constraint returned by
124:             *     {@link #getConstraint getConstraint()}
125:             * <li><em>&lt;sortorders&gt;</em> is the list returned by
126:             *     {@link #getSortOrders getSortOrders()}
127:             * <li><em>&lt;max&gt;</em> is value returned by
128:             *     {@link #getMaxNumber getMaxNumber()}
129:             * <li><em>&lt;offset&gt;</em> is value returned by
130:             *     {@link #getOffset getOffset()}
131:             * </ul>
132:             *
133:             * @return A string representation of this SearchQuery.
134:             */
135:            public String toString();
136:
137:        }