plugins/org.eclipse.mat.ui.help/reference/oqlsyntaxwhere.dita

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<!DOCTYPE reference PUBLIC "-//OASIS//DTD DITA Reference//EN" "reference.dtd" >
<reference id="ref_oqlsyntaxwhere" xml:lang="en-us">
	<title>WHERE Clause</title>
	<shortdesc />

	<prolog>
		<copyright>
			<copyryear year=""></copyryear>
			<copyrholder>
				Copyright (c) 2008, 2020 SAP AG and others.
			    All rights reserved. This program and the accompanying materials
			    are made available under the terms of the Eclipse Public License 2.0
			    which accompanies this distribution, and is available at
			    https://www.eclipse.org/legal/epl-2.0/
			</copyrholder>
		</copyright>
	</prolog>

	<refbody>
		<section>
			<p>
				The <codeph>WHERE</codeph> clause specifies search conditions, that
				remove unwanted data from the query result. The
				following operators, are in order of precedence. The
				operators are evaluated in the specified order:

			</p>
			<title>
				&gt;=, &lt;=, &gt;, &lt;, [ NOT ] LIKE, [ NOT ] IN, IMPLEMENTS
				(relational operations)
			</title>
			<codeblock>SELECT * FROM java.lang.String s WHERE s.count >= 100</codeblock>
			<codeblock>SELECT * FROM java.lang.String s WHERE toString(s) LIKE ".*day"</codeblock>
			<p>
			<codeblock>SELECT * FROM java.lang.String s WHERE s.value NOT IN dominators(s)</codeblock>
			The right hand side of <codeph>IN</codeph> can be a Java <apiname>java.util.List</apiname>, Java <apiname>Object[]</apiname>
			array, a Java <apiname>int[]</apiname> array, or a result table from another
			<codeph>SELECT</codeph>, in which case the item is searched among the entries
			in the first column.
			If the right hand side is a Java <apiname>int[]</apiname> array and the left
			hand side is an <apiname>IObject</apiname> then the object ID is searched for
			in the array.
			</p>
			<p>
			<codeblock>SELECT * FROM java.lang.Class c WHERE c IMPLEMENTS org.eclipse.mat.snapshot.model.IClass</codeblock>
			<codeph>IMPLEMENTS</codeph> works when the left hand side is any object or an integer
			which is considered as an object ID and the actual IObject is used for the test.
			</p>
		</section>
		<section>
			<title>=, != (equality operations)</title>
			<codeblock>SELECT * FROM java.lang.String s WHERE toString(s) = "monday"</codeblock>
		</section>
		<section>
			<title>AND (conditional AND operation)</title>
			<codeblock>SELECT * FROM java.lang.String s WHERE s.count > 100 AND s.@retainedHeapSize > s.@usedHeapSize</codeblock>
		</section>
		<section>
			<title>OR (conditional OR operation)</title>
			<codeblock>SELECT * FROM java.lang.String s WHERE s.count > 1000 OR s.value.@length > 1000</codeblock>
			<p>
				Operators can be applied to expressions, constant
				literals and sub queries. Valid expressions are
				explained in the next sections.
			</p>
		</section>
		<section>
			<title>Literal Expression</title>
			<p>Boolean, String, Integer, Long, Character, Float, Double and null literals:</p>
			<codeblock>SELECT * FROM java.lang.String s
         WHERE ( s.count > 1000 ) = true
           OR toString(s) = "monday"
           OR dominators(s).size() = 0
           OR s.@retainedHeapSize > 1024L
           OR s.value != null AND s.value.@valueArray.@length >= 1 AND s.value.@valueArray.get(0) = 'j'
           </codeblock>
           <codeblock>SELECT * FROM instanceof java.lang.Number s
         WHERE s.value > -1 
           OR s.value > -1L
           OR s.value > 0.1
           OR s.value > -0.1E-2F
           OR s.value > 0.1D
           OR s.value > -0.1E-2D
           OR s.value > 0.1
           OR s.value > -0.1E-2F
           OR s.value > 0.1D
           OR s.value > -0.1E-2D
           </codeblock>
		</section>
	</refbody>
</reference>