| <!DOCTYPE HTML> |
| <!-- NewPage --> |
| <html lang="en"> |
| <head> |
| <!-- Generated by javadoc --> |
| <title>RexUnknownAs (Apache Calcite API)</title> |
| <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> |
| <link rel="stylesheet" type="text/css" href="../../../../stylesheet.css" title="Style"> |
| <link rel="stylesheet" type="text/css" href="../../../../jquery/jquery-ui.css" title="Style"> |
| <script type="text/javascript" src="../../../../script.js"></script> |
| <script type="text/javascript" src="../../../../jquery/jszip/dist/jszip.min.js"></script> |
| <script type="text/javascript" src="../../../../jquery/jszip-utils/dist/jszip-utils.min.js"></script> |
| <!--[if IE]> |
| <script type="text/javascript" src="../../../../jquery/jszip-utils/dist/jszip-utils-ie.min.js"></script> |
| <![endif]--> |
| <script type="text/javascript" src="../../../../jquery/jquery-3.3.1.js"></script> |
| <script type="text/javascript" src="../../../../jquery/jquery-migrate-3.0.1.js"></script> |
| <script type="text/javascript" src="../../../../jquery/jquery-ui.js"></script> |
| </head> |
| <body> |
| <script type="text/javascript"><!-- |
| try { |
| if (location.href.indexOf('is-external=true') == -1) { |
| parent.document.title="RexUnknownAs (Apache Calcite API)"; |
| } |
| } |
| catch(err) { |
| } |
| //--> |
| var data = {"i0":9,"i1":10,"i2":10,"i3":9,"i4":9}; |
| var tabs = {65535:["t0","All Methods"],1:["t1","Static Methods"],2:["t2","Instance Methods"],8:["t4","Concrete Methods"]}; |
| var altColor = "altColor"; |
| var rowColor = "rowColor"; |
| var tableTab = "tableTab"; |
| var activeTableTab = "activeTableTab"; |
| var pathtoroot = "../../../../"; |
| var useModuleDirectories = true; |
| loadScripts(document, 'script');</script> |
| <noscript> |
| <div>JavaScript is disabled on your browser.</div> |
| </noscript> |
| <header role="banner"> |
| <nav role="navigation"> |
| <div class="fixedNav"> |
| <!-- ========= START OF TOP NAVBAR ======= --> |
| <div class="topNav"><a id="navbar.top"> |
| <!-- --> |
| </a> |
| <div class="skipNav"><a href="#skip.navbar.top" title="Skip navigation links">Skip navigation links</a></div> |
| <a id="navbar.top.firstrow"> |
| <!-- --> |
| </a> |
| <ul class="navList" title="Navigation"> |
| <li><a href="../../../../index.html">Overview</a></li> |
| <li><a href="package-summary.html">Package</a></li> |
| <li class="navBarCell1Rev">Class</li> |
| <li><a href="class-use/RexUnknownAs.html">Use</a></li> |
| <li><a href="package-tree.html">Tree</a></li> |
| <li><a href="../../../../deprecated-list.html">Deprecated</a></li> |
| <li><a href="../../../../index-all.html">Index</a></li> |
| <li><a href="../../../../help-doc.html">Help</a></li> |
| </ul> |
| </div> |
| <div class="subNav"> |
| <ul class="navList" id="allclasses_navbar_top"> |
| <li><a href="../../../../allclasses.html">All Classes</a></li> |
| </ul> |
| <ul class="navListSearch"> |
| <li><label for="search">SEARCH:</label> |
| <input type="text" id="search" value="search" disabled="disabled"> |
| <input type="reset" id="reset" value="reset" disabled="disabled"> |
| </li> |
| </ul> |
| <div> |
| <script type="text/javascript"><!-- |
| allClassesLink = document.getElementById("allclasses_navbar_top"); |
| if(window==top) { |
| allClassesLink.style.display = "block"; |
| } |
| else { |
| allClassesLink.style.display = "none"; |
| } |
| //--> |
| </script> |
| <noscript> |
| <div>JavaScript is disabled on your browser.</div> |
| </noscript> |
| </div> |
| <div> |
| <ul class="subNavList"> |
| <li>Summary: </li> |
| <li>Nested | </li> |
| <li><a href="#enum.constant.summary">Enum Constants</a> | </li> |
| <li>Field | </li> |
| <li><a href="#method.summary">Method</a></li> |
| </ul> |
| <ul class="subNavList"> |
| <li>Detail: </li> |
| <li><a href="#enum.constant.detail">Enum Constants</a> | </li> |
| <li>Field | </li> |
| <li><a href="#method.detail">Method</a></li> |
| </ul> |
| </div> |
| <a id="skip.navbar.top"> |
| <!-- --> |
| </a></div> |
| <!-- ========= END OF TOP NAVBAR ========= --> |
| </div> |
| <div class="navPadding"> </div> |
| <script type="text/javascript"><!-- |
| $('.navPadding').css('padding-top', $('.fixedNav').css("height")); |
| //--> |
| </script> |
| </nav> |
| </header> |
| <!-- ======== START OF CLASS DATA ======== --> |
| <main role="main"> |
| <div class="header"> |
| <div class="subTitle"><span class="packageLabelInType">Package</span> <a href="package-summary.html">org.apache.calcite.rex</a></div> |
| <h2 title="Enum RexUnknownAs" class="title">Enum RexUnknownAs</h2> |
| </div> |
| <div class="contentContainer"> |
| <ul class="inheritance"> |
| <li>java.lang.Object</li> |
| <li> |
| <ul class="inheritance"> |
| <li>java.lang.Enum<<a href="RexUnknownAs.html" title="enum in org.apache.calcite.rex">RexUnknownAs</a>></li> |
| <li> |
| <ul class="inheritance"> |
| <li>org.apache.calcite.rex.RexUnknownAs</li> |
| </ul> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| <div class="description"> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <dl> |
| <dt>All Implemented Interfaces:</dt> |
| <dd><code>java.io.Serializable</code>, <code>java.lang.Comparable<<a href="RexUnknownAs.html" title="enum in org.apache.calcite.rex">RexUnknownAs</a>></code></dd> |
| </dl> |
| <hr> |
| <pre>public enum <span class="typeNameLabel">RexUnknownAs</span> |
| extends java.lang.Enum<<a href="RexUnknownAs.html" title="enum in org.apache.calcite.rex">RexUnknownAs</a>></pre> |
| <div class="block">Policy for whether a simplified expression may instead return another |
| value. |
| |
| <p>In particular, it deals with converting three-valued logic (TRUE, FALSE, |
| UNKNOWN) to two-valued logic (TRUE, FALSE) for callers that treat the UNKNOWN |
| value the same as TRUE or FALSE. |
| |
| <p>Sometimes the three-valued version of the expression is simpler (has a |
| smaller expression tree) than the two-valued version. In these cases, |
| favor simplicity over reduction to two-valued logic.</div> |
| <dl> |
| <dt><span class="seeLabel">See Also:</span></dt> |
| <dd><a href="RexSimplify.html" title="class in org.apache.calcite.rex"><code>RexSimplify</code></a></dd> |
| </dl> |
| </li> |
| </ul> |
| </div> |
| <div class="summary"> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <!-- =========== ENUM CONSTANT SUMMARY =========== --> |
| <section role="region"> |
| <ul class="blockList"> |
| <li class="blockList"><a id="enum.constant.summary"> |
| <!-- --> |
| </a> |
| <h3>Enum Constant Summary</h3> |
| <table class="memberSummary"> |
| <caption><span>Enum Constants</span><span class="tabEnd"> </span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Enum Constant</th> |
| <th class="colLast" scope="col">Description</th> |
| </tr> |
| <tr class="altColor"> |
| <th class="colFirst" scope="row"><code><span class="memberNameLink"><a href="#FALSE">FALSE</a></span></code></th> |
| <td class="colLast"> |
| <div class="block">Policy that indicates that the expression is being used in a context |
| Where an UNKNOWN value is treated in the same way as FALSE.</div> |
| </td> |
| </tr> |
| <tr class="rowColor"> |
| <th class="colFirst" scope="row"><code><span class="memberNameLink"><a href="#TRUE">TRUE</a></span></code></th> |
| <td class="colLast"> |
| <div class="block">Policy that indicates that the expression is being used in a context |
| Where an UNKNOWN value is treated in the same way as TRUE.</div> |
| </td> |
| </tr> |
| <tr class="altColor"> |
| <th class="colFirst" scope="row"><code><span class="memberNameLink"><a href="#UNKNOWN">UNKNOWN</a></span></code></th> |
| <td class="colLast"> |
| <div class="block">Policy that indicates that the expression is being used in a context |
| Where an UNKNOWN value is treated as is.</div> |
| </td> |
| </tr> |
| </table> |
| </li> |
| </ul> |
| </section> |
| <!-- ======== CONSTRUCTOR SUMMARY ======== --> |
| <section role="region"> |
| <ul class="blockList"> |
| <li class="blockList"><a id="constructor.summary"> |
| <!-- --> |
| </a> |
| <h3>Constructor Summary</h3> |
| <table class="memberSummary"> |
| <caption><span>Constructors</span><span class="tabEnd"> </span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Modifier</th> |
| <th class="colSecond" scope="col">Constructor</th> |
| <th class="colLast" scope="col">Description</th> |
| </tr> |
| <tr class="altColor"> |
| <td class="colFirst"><code>private </code></td> |
| <th class="colConstructorName" scope="row"><code><span class="memberNameLink"><a href="#%3Cinit%3E()">RexUnknownAs</a></span>()</code></th> |
| <td class="colLast"> </td> |
| </tr> |
| </table> |
| </li> |
| </ul> |
| </section> |
| <!-- ========== METHOD SUMMARY =========== --> |
| <section role="region"> |
| <ul class="blockList"> |
| <li class="blockList"><a id="method.summary"> |
| <!-- --> |
| </a> |
| <h3>Method Summary</h3> |
| <table class="memberSummary"> |
| <caption><span id="t0" class="activeTableTab"><span>All Methods</span><span class="tabEnd"> </span></span><span id="t1" class="tableTab"><span><a href="javascript:show(1);">Static Methods</a></span><span class="tabEnd"> </span></span><span id="t2" class="tableTab"><span><a href="javascript:show(2);">Instance Methods</a></span><span class="tabEnd"> </span></span><span id="t4" class="tableTab"><span><a href="javascript:show(8);">Concrete Methods</a></span><span class="tabEnd"> </span></span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Modifier and Type</th> |
| <th class="colSecond" scope="col">Method</th> |
| <th class="colLast" scope="col">Description</th> |
| </tr> |
| <tr id="i0" class="altColor"> |
| <td class="colFirst"><code>static <a href="RexUnknownAs.html" title="enum in org.apache.calcite.rex">RexUnknownAs</a></code></td> |
| <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#falseIf(boolean)">falseIf</a></span>​(boolean unknownAsFalse)</code></th> |
| <td class="colLast"> |
| <div class="block">Returns <a href="#FALSE"><code>FALSE</code></a> if <code>unknownAsFalse</code> is true, |
| <a href="#UNKNOWN"><code>UNKNOWN</code></a> otherwise.</div> |
| </td> |
| </tr> |
| <tr id="i1" class="rowColor"> |
| <td class="colFirst"><code><a href="RexUnknownAs.html" title="enum in org.apache.calcite.rex">RexUnknownAs</a></code></td> |
| <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#negate()">negate</a></span>()</code></th> |
| <td class="colLast"> </td> |
| </tr> |
| <tr id="i2" class="altColor"> |
| <td class="colFirst"><code>boolean</code></td> |
| <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#toBoolean()">toBoolean</a></span>()</code></th> |
| <td class="colLast"> </td> |
| </tr> |
| <tr id="i3" class="rowColor"> |
| <td class="colFirst"><code>static <a href="RexUnknownAs.html" title="enum in org.apache.calcite.rex">RexUnknownAs</a></code></td> |
| <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#valueOf(java.lang.String)">valueOf</a></span>​(java.lang.String name)</code></th> |
| <td class="colLast"> |
| <div class="block">Returns the enum constant of this type with the specified name.</div> |
| </td> |
| </tr> |
| <tr id="i4" class="altColor"> |
| <td class="colFirst"><code>static <a href="RexUnknownAs.html" title="enum in org.apache.calcite.rex">RexUnknownAs</a>[]</code></td> |
| <th class="colSecond" scope="row"><code><span class="memberNameLink"><a href="#values()">values</a></span>()</code></th> |
| <td class="colLast"> |
| <div class="block">Returns an array containing the constants of this enum type, in |
| the order they are declared.</div> |
| </td> |
| </tr> |
| </table> |
| <ul class="blockList"> |
| <li class="blockList"><a id="methods.inherited.from.class.java.lang.Enum"> |
| <!-- --> |
| </a> |
| <h3>Methods inherited from class java.lang.Enum</h3> |
| <code>clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf</code></li> |
| </ul> |
| <ul class="blockList"> |
| <li class="blockList"><a id="methods.inherited.from.class.java.lang.Object"> |
| <!-- --> |
| </a> |
| <h3>Methods inherited from class java.lang.Object</h3> |
| <code>getClass, notify, notifyAll, wait, wait, wait</code></li> |
| </ul> |
| </li> |
| </ul> |
| </section> |
| </li> |
| </ul> |
| </div> |
| <div class="details"> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <!-- ============ ENUM CONSTANT DETAIL =========== --> |
| <section role="region"> |
| <ul class="blockList"> |
| <li class="blockList"><a id="enum.constant.detail"> |
| <!-- --> |
| </a> |
| <h3>Enum Constant Detail</h3> |
| <a id="FALSE"> |
| <!-- --> |
| </a> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <h4>FALSE</h4> |
| <pre>public static final <a href="RexUnknownAs.html" title="enum in org.apache.calcite.rex">RexUnknownAs</a> FALSE</pre> |
| <div class="block">Policy that indicates that the expression is being used in a context |
| Where an UNKNOWN value is treated in the same way as FALSE. Therefore, when |
| simplifying the expression, it is acceptable for the simplified expression |
| to evaluate to FALSE in some situations where the original expression would |
| evaluate to UNKNOWN. |
| |
| <p>SQL predicates (<code>WHERE</code>, <code>ON</code>, <code>HAVING</code> and |
| <code>FILTER (WHERE)</code> clauses, a <code>WHEN</code> clause of a <code>CASE</code> |
| expression, and in <code>CHECK</code> constraints) all treat UNKNOWN as FALSE. |
| |
| <p>If the simplified expression never returns UNKNOWN, the simplifier |
| should make this clear to the caller, if possible, by marking its type as |
| <code>BOOLEAN NOT NULL</code>.</div> |
| </li> |
| </ul> |
| <a id="TRUE"> |
| <!-- --> |
| </a> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <h4>TRUE</h4> |
| <pre>public static final <a href="RexUnknownAs.html" title="enum in org.apache.calcite.rex">RexUnknownAs</a> TRUE</pre> |
| <div class="block">Policy that indicates that the expression is being used in a context |
| Where an UNKNOWN value is treated in the same way as TRUE. Therefore, when |
| simplifying the expression, it is acceptable for the simplified expression |
| to evaluate to TRUE in some situations where the original expression would |
| evaluate to UNKNOWN. |
| |
| <p>This does not occur commonly in SQL. However, it occurs internally |
| during simplification. For example, "<code>WHERE NOT expression</code>" |
| evaluates "<code>NOT expression</code>" in a context that treats UNKNOWN as |
| FALSE; it is useful to consider that "<code>expression</code>" is evaluated in a |
| context that treats UNKNOWN as TRUE. |
| |
| <p>If the simplified expression never returns UNKNOWN, the simplifier |
| should make this clear to the caller, if possible, by marking its type as |
| <code>BOOLEAN NOT NULL</code>.</div> |
| </li> |
| </ul> |
| <a id="UNKNOWN"> |
| <!-- --> |
| </a> |
| <ul class="blockListLast"> |
| <li class="blockList"> |
| <h4>UNKNOWN</h4> |
| <pre>public static final <a href="RexUnknownAs.html" title="enum in org.apache.calcite.rex">RexUnknownAs</a> UNKNOWN</pre> |
| <div class="block">Policy that indicates that the expression is being used in a context |
| Where an UNKNOWN value is treated as is. This occurs: |
| |
| <ul> |
| <li>In any expression whose type is not <code>BOOLEAN</code> |
| <li>In <code>BOOLEAN</code> expressions that are <code>NOT NULL</code> |
| <li>In <code>BOOLEAN</code> expressions where <code>UNKNOWN</code> should be |
| returned as is, for example in a <code>SELECT</code> clause, or within an |
| expression such as an operand to <code>AND</code>, <code>OR</code> or |
| <code>NOT</code> |
| </ul> |
| |
| <p>If you are unsure, use UNKNOWN. It is the safest option.</div> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| </section> |
| <!-- ========= CONSTRUCTOR DETAIL ======== --> |
| <section role="region"> |
| <ul class="blockList"> |
| <li class="blockList"><a id="constructor.detail"> |
| <!-- --> |
| </a> |
| <h3>Constructor Detail</h3> |
| <a id="<init>()"> |
| <!-- --> |
| </a> |
| <ul class="blockListLast"> |
| <li class="blockList"> |
| <h4>RexUnknownAs</h4> |
| <pre>private RexUnknownAs()</pre> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| </section> |
| <!-- ============ METHOD DETAIL ========== --> |
| <section role="region"> |
| <ul class="blockList"> |
| <li class="blockList"><a id="method.detail"> |
| <!-- --> |
| </a> |
| <h3>Method Detail</h3> |
| <a id="values()"> |
| <!-- --> |
| </a> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <h4>values</h4> |
| <pre class="methodSignature">public static <a href="RexUnknownAs.html" title="enum in org.apache.calcite.rex">RexUnknownAs</a>[] values()</pre> |
| <div class="block">Returns an array containing the constants of this enum type, in |
| the order they are declared. This method may be used to iterate |
| over the constants as follows: |
| <pre> |
| for (RexUnknownAs c : RexUnknownAs.values()) |
| System.out.println(c); |
| </pre></div> |
| <dl> |
| <dt><span class="returnLabel">Returns:</span></dt> |
| <dd>an array containing the constants of this enum type, in the order they are declared</dd> |
| </dl> |
| </li> |
| </ul> |
| <a id="valueOf(java.lang.String)"> |
| <!-- --> |
| </a> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <h4>valueOf</h4> |
| <pre class="methodSignature">public static <a href="RexUnknownAs.html" title="enum in org.apache.calcite.rex">RexUnknownAs</a> valueOf​(java.lang.String name)</pre> |
| <div class="block">Returns the enum constant of this type with the specified name. |
| The string must match <i>exactly</i> an identifier used to declare an |
| enum constant in this type. (Extraneous whitespace characters are |
| not permitted.)</div> |
| <dl> |
| <dt><span class="paramLabel">Parameters:</span></dt> |
| <dd><code>name</code> - the name of the enum constant to be returned.</dd> |
| <dt><span class="returnLabel">Returns:</span></dt> |
| <dd>the enum constant with the specified name</dd> |
| <dt><span class="throwsLabel">Throws:</span></dt> |
| <dd><code>java.lang.IllegalArgumentException</code> - if this enum type has no constant with the specified name</dd> |
| <dd><code>java.lang.NullPointerException</code> - if the argument is null</dd> |
| </dl> |
| </li> |
| </ul> |
| <a id="falseIf(boolean)"> |
| <!-- --> |
| </a> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <h4>falseIf</h4> |
| <pre class="methodSignature">@Nonnull |
| public static <a href="RexUnknownAs.html" title="enum in org.apache.calcite.rex">RexUnknownAs</a> falseIf​(boolean unknownAsFalse)</pre> |
| <div class="block">Returns <a href="#FALSE"><code>FALSE</code></a> if <code>unknownAsFalse</code> is true, |
| <a href="#UNKNOWN"><code>UNKNOWN</code></a> otherwise.</div> |
| </li> |
| </ul> |
| <a id="toBoolean()"> |
| <!-- --> |
| </a> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <h4>toBoolean</h4> |
| <pre class="methodSignature">public boolean toBoolean()</pre> |
| </li> |
| </ul> |
| <a id="negate()"> |
| <!-- --> |
| </a> |
| <ul class="blockListLast"> |
| <li class="blockList"> |
| <h4>negate</h4> |
| <pre class="methodSignature">public <a href="RexUnknownAs.html" title="enum in org.apache.calcite.rex">RexUnknownAs</a> negate()</pre> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| </section> |
| </li> |
| </ul> |
| </div> |
| </div> |
| </main> |
| <!-- ========= END OF CLASS DATA ========= --> |
| <footer role="contentinfo"> |
| <nav role="navigation"> |
| <!-- ======= START OF BOTTOM NAVBAR ====== --> |
| <div class="bottomNav"><a id="navbar.bottom"> |
| <!-- --> |
| </a> |
| <div class="skipNav"><a href="#skip.navbar.bottom" title="Skip navigation links">Skip navigation links</a></div> |
| <a id="navbar.bottom.firstrow"> |
| <!-- --> |
| </a> |
| <ul class="navList" title="Navigation"> |
| <li><a href="../../../../index.html">Overview</a></li> |
| <li><a href="package-summary.html">Package</a></li> |
| <li class="navBarCell1Rev">Class</li> |
| <li><a href="class-use/RexUnknownAs.html">Use</a></li> |
| <li><a href="package-tree.html">Tree</a></li> |
| <li><a href="../../../../deprecated-list.html">Deprecated</a></li> |
| <li><a href="../../../../index-all.html">Index</a></li> |
| <li><a href="../../../../help-doc.html">Help</a></li> |
| </ul> |
| </div> |
| <div class="subNav"> |
| <ul class="navList" id="allclasses_navbar_bottom"> |
| <li><a href="../../../../allclasses.html">All Classes</a></li> |
| </ul> |
| <div> |
| <script type="text/javascript"><!-- |
| allClassesLink = document.getElementById("allclasses_navbar_bottom"); |
| if(window==top) { |
| allClassesLink.style.display = "block"; |
| } |
| else { |
| allClassesLink.style.display = "none"; |
| } |
| //--> |
| </script> |
| <noscript> |
| <div>JavaScript is disabled on your browser.</div> |
| </noscript> |
| </div> |
| <div> |
| <ul class="subNavList"> |
| <li>Summary: </li> |
| <li>Nested | </li> |
| <li><a href="#enum.constant.summary">Enum Constants</a> | </li> |
| <li>Field | </li> |
| <li><a href="#method.summary">Method</a></li> |
| </ul> |
| <ul class="subNavList"> |
| <li>Detail: </li> |
| <li><a href="#enum.constant.detail">Enum Constants</a> | </li> |
| <li>Field | </li> |
| <li><a href="#method.detail">Method</a></li> |
| </ul> |
| </div> |
| <a id="skip.navbar.bottom"> |
| <!-- --> |
| </a></div> |
| <!-- ======== END OF BOTTOM NAVBAR ======= --> |
| </nav> |
| <p class="legalCopy"><small>Copyright © 2012–2019 <a href="https://www.apache.org/">The Apache Software Foundation</a>. All rights reserved.</small></p> |
| </footer> |
| </body> |
| </html> |
