| <!doctype html><html lang=en class=no-js><head><meta charset=utf-8><meta http-equiv=x-ua-compatible content="IE=edge"><meta name=viewport content="width=device-width,initial-scale=1"><title>Beam ZetaSQL conversion rules</title><meta name=description content="Apache Beam is an open source, unified model and set of language-specific SDKs for defining and executing data processing workflows, and also data ingestion and integration flows, supporting Enterprise Integration Patterns (EIPs) and Domain Specific Languages (DSLs). Dataflow pipelines simplify the mechanics of large-scale batch and streaming data processing and can run on a number of runtimes like Apache Flink, Apache Spark, and Google Cloud Dataflow (a cloud service). Beam also brings DSL in different languages, allowing users to easily implement their data integration processes."><link href="https://fonts.googleapis.com/css?family=Roboto:100,300,400,500,700" rel=stylesheet><link rel=preload href=/scss/main.min.d653ded46cd5f19a535cb20567fce9699849fe46f950d91ac6bf336db8ff8724.css as=style><link href=/scss/main.min.d653ded46cd5f19a535cb20567fce9699849fe46f950d91ac6bf336db8ff8724.css rel=stylesheet integrity><script src=https://code.jquery.com/jquery-2.2.4.min.js></script><style>.body__contained img{max-width:100%}</style><script type=text/javascript src=/js/bootstrap.min.2979f9a6e32fc42c3e7406339ee9fe76b31d1b52059776a02b4a7fa6a4fd280a.js defer></script> |
| <script type=text/javascript src=/js/language-switch-v2.min.121952b7980b920320ab229551857669209945e39b05ba2b433a565385ca44c6.js defer></script> |
| <script type=text/javascript src=/js/fix-menu.min.039174b67107465f2090a493f91e126f7aa797f29420f9edab8a54d9dd4b3d2d.js defer></script> |
| <script type=text/javascript src=/js/section-nav.min.1405fd5e70fab5f6c54037c269b1d137487d8f3d1b3009032525f6db3fbce991.js defer></script> |
| <script type=text/javascript src=/js/page-nav.min.af231204c9c52c5089d53a4c02739eacbb7f939e3be1c6ffcc212e0ac4dbf879.js defer></script> |
| <script type=text/javascript src=/js/expandable-list.min.75a4526624a3b8898fe7fb9e3428c205b581f8b38c7926922467aef17eac69f2.js defer></script> |
| <script type=text/javascript src=/js/copy-to-clipboard.min.364c06423d7e8993fc42bb4abc38c03195bc8386db26d18774ce775d08d5b18d.js defer></script> |
| <script type=text/javascript src=/js/calendar.min.336664054fa0f52b08bbd4e3c59b5cb6d63dcfb2b4d602839746516b0817446b.js defer></script> |
| <script type=text/javascript src=/js/fix-playground-nested-scroll.min.0283f1037cb1b9d5074c6eaf041292b524a8148a7cdb803d5ccd6d1fc4eb3253.js defer></script> |
| <script type=text/javascript src=/js/anchor-content-jump-fix.min.22d3240f81632e4c11179b9d2aaf37a40da9414333c43aa97344e8b21a7df0e4.js defer></script> |
| <link rel=alternate type=application/rss+xml title="Apache Beam" href=/feed.xml><link rel=canonical href=/documentation/dsls/sql/zetasql/conversion-rules/ data-proofer-ignore><link rel="shortcut icon" type=image/x-icon href=/images/favicon.ico><link rel=stylesheet href=https://use.fontawesome.com/releases/v5.4.1/css/all.css integrity=sha384-5sAR7xN1Nv6T6+dT2mhtzEpVJvfS3NScPQTrOxhwjIuvcA67KV2R5Jz6kr4abQsz crossorigin=anonymous><link rel=stylesheet href=https://unpkg.com/swiper@8/swiper-bundle.min.css><script async src=https://platform.twitter.com/widgets.js></script> |
| <script>(function(e,t,n,s,o,i,a){e.GoogleAnalyticsObject=o,e[o]=e[o]||function(){(e[o].q=e[o].q||[]).push(arguments)},e[o].l=1*new Date,i=t.createElement(n),a=t.getElementsByTagName(n)[0],i.async=1,i.src=s,a.parentNode.insertBefore(i,a)})(window,document,"script","//www.google-analytics.com/analytics.js","ga"),ga("create","UA-73650088-1","auto"),ga("send","pageview")</script><script>(function(e,t,n,s,o,i){e.hj=e.hj||function(){(e.hj.q=e.hj.q||[]).push(arguments)},e._hjSettings={hjid:2182187,hjsv:6},o=t.getElementsByTagName("head")[0],i=t.createElement("script"),i.async=1,i.src=n+e._hjSettings.hjid+s+e._hjSettings.hjsv,o.appendChild(i)})(window,document,"https://static.hotjar.com/c/hotjar-",".js?sv=")</script></head><body class=body data-spy=scroll data-target=.page-nav data-offset=0><nav class="navigation-bar-mobile header navbar navbar-fixed-top"><div class=navbar-header><a href=/ class=navbar-brand><img alt=Brand style=height:46px;width:43px src=/images/beam_logo_navbar_mobile.png></a> |
| <a class=navbar-link href=/get-started/>Get Started</a> |
| <a class=navbar-link href=/documentation/>Documentation</a> |
| <button type=button class="navbar-toggle menu-open" aria-expanded=false aria-controls=navbar onclick=openMenu()> |
| <span class=sr-only>Toggle navigation</span> |
| <span class=icon-bar></span> |
| <span class=icon-bar></span> |
| <span class=icon-bar></span></button></div><div class="navbar-mask closed"></div><div id=navbar class="navbar-container closed"><button type=button class=navbar-toggle aria-expanded=false aria-controls=navbar id=closeMenu> |
| <span class=sr-only>Toggle navigation</span> |
| <span class=icon-bar></span> |
| <span class=icon-bar></span> |
| <span class=icon-bar></span></button><ul class="nav navbar-nav"><li><div class=searchBar-mobile><script>(function(){var t,n="012923275103528129024:4emlchv9wzi",e=document.createElement("script");e.type="text/javascript",e.async=!0,e.src="https://cse.google.com/cse.js?cx="+n,t=document.getElementsByTagName("script")[0],t.parentNode.insertBefore(e,t)})()</script><gcse:search></gcse:search></div></li><li><a class=navbar-link href=/about>About</a></li><li><a class=navbar-link href=/get-started/>Get Started</a></li><li><span class=navbar-link>Documentation</span><ul><li><a href=/documentation/>General</a></li><li><a href=/documentation/sdks/java/>Languages</a></li><li><a href=/documentation/runners/capability-matrix/>Runners</a></li><li><a href=/documentation/io/connectors/>I/O Connectors</a></li></ul></li><li><a class=navbar-link href=/roadmap/>Roadmap</a></li><li><a class=navbar-link href=/community/>Community</a></li><li><a class=navbar-link href=/contribute/>Contribute</a></li><li><a class=navbar-link href=/blog/>Blog</a></li><li><a class=navbar-link href=/case-studies/>Case Studies</a></li></ul><ul class="nav navbar-nav navbar-right"><li><a href=https://github.com/apache/beam/edit/master/website/www/site/content/en/documentation/dsls/sql/zetasql/conversion-rules.md data-proofer-ignore><svg xmlns="http://www.w3.org/2000/svg" width="25" height="24" fill="none" viewBox="0 0 25 24"><path stroke="#ff6d00" stroke-linecap="round" stroke-linejoin="round" stroke-width="2.75" d="M4.543 20h4l10.5-10.5c.53-.53.828-1.25.828-2s-.298-1.47-.828-2-1.25-.828-2-.828-1.47.298-2 .828L4.543 16v4zm9.5-13.5 4 4"/></svg></a></li><li class=dropdown><a href=# class=dropdown-toggle id=apache-dropdown data-toggle=dropdown role=button aria-haspopup=true aria-expanded=false><img src=https://www.apache.org/foundation/press/kit/feather_small.png alt="Apache Logo" style=height:20px> |
| Apache |
| <span class=arrow-icon><svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" fill="none" viewBox="0 0 20 20"><circle cx="10" cy="10" r="10" fill="#ff6d00"/><path stroke="#fff" stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M8.535 5.28l4.573 4.818-4.573 4.403"/></svg></span></a><ul class="dropdown-menu dropdown-menu-right"><li><a target=_blank href=https://www.apache.org/>ASF Homepage</a></li><li><a target=_blank href=https://www.apache.org/licenses/>License</a></li><li><a target=_blank href=https://www.apache.org/security/>Security</a></li><li><a target=_blank href=https://www.apache.org/foundation/thanks.html>Thanks</a></li><li><a target=_blank href=https://www.apache.org/foundation/sponsorship.html>Sponsorship</a></li><li><a target=_blank href=https://www.apache.org/foundation/policies/conduct>Code of Conduct</a></li></ul></li></ul></div></nav><nav class=navigation-bar-desktop><a href=/ class=navbar-logo><img src=/images/beam_logo_navbar.png alt="Beam Logo"></a><div class=navbar-bar-left><div class=navbar-links><a class=navbar-link href=/about>About</a> |
| <a class=navbar-link href=/get-started/>Get Started</a><li class="dropdown navbar-dropdown navbar-dropdown-documentation"><a href=# class="dropdown-toggle navbar-link" role=button aria-haspopup=true aria-expanded=false>Documentation |
| <span><svg xmlns="http://www.w3.org/2000/svg" width="12" height="11" fill="none" viewBox="0 0 12 11"><path stroke="#ff6d00" stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M10.666 4.535 5.847 9.108 1.444 4.535"/></svg></span></a><ul class=dropdown-menu><li><a class=navbar-dropdown-menu-link href=/documentation/>General</a></li><li><a class=navbar-dropdown-menu-link href=/documentation/sdks/java/>Languages</a></li><li><a class=navbar-dropdown-menu-link href=/documentation/runners/capability-matrix/>Runners</a></li><li><a class=navbar-dropdown-menu-link href=/documentation/io/connectors/>I/O Connectors</a></li></ul></li><a class=navbar-link href=/roadmap/>Roadmap</a> |
| <a class=navbar-link href=/community/>Community</a> |
| <a class=navbar-link href=/contribute/>Contribute</a> |
| <a class=navbar-link href=/blog/>Blog</a> |
| <a class=navbar-link href=/case-studies/>Case Studies</a></div><div id=iconsBar><a type=button onclick=showSearch()><svg xmlns="http://www.w3.org/2000/svg" width="25" height="24" fill="none" viewBox="0 0 25 24"><path stroke="#ff6d00" stroke-linecap="round" stroke-linejoin="round" stroke-width="2.75" d="M10.191 17c3.866.0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm11 4-6-6"/></svg></a><a target=_blank href=https://github.com/apache/beam/edit/master/website/www/site/content/en/documentation/dsls/sql/zetasql/conversion-rules.md data-proofer-ignore><svg xmlns="http://www.w3.org/2000/svg" width="25" height="24" fill="none" viewBox="0 0 25 24"><path stroke="#ff6d00" stroke-linecap="round" stroke-linejoin="round" stroke-width="2.75" d="M4.543 20h4l10.5-10.5c.53-.53.828-1.25.828-2s-.298-1.47-.828-2-1.25-.828-2-.828-1.47.298-2 .828L4.543 16v4zm9.5-13.5 4 4"/></svg></a><li class="dropdown navbar-dropdown navbar-dropdown-apache"><a href=# class=dropdown-toggle role=button aria-haspopup=true aria-expanded=false><img src=https://www.apache.org/foundation/press/kit/feather_small.png alt="Apache Logo" style=height:20px> |
| Apache |
| <span class=arrow-icon><svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" fill="none" viewBox="0 0 20 20"><circle cx="10" cy="10" r="10" fill="#ff6d00"/><path stroke="#fff" stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M8.535 5.28l4.573 4.818-4.573 4.403"/></svg></span></a><ul class=dropdown-menu><li><a class=navbar-dropdown-menu-link target=_blank href=https://www.apache.org/>ASF Homepage</a></li><li><a class=navbar-dropdown-menu-link target=_blank href=https://www.apache.org/licenses/>License</a></li><li><a class=navbar-dropdown-menu-link target=_blank href=https://www.apache.org/security/>Security</a></li><li><a class=navbar-dropdown-menu-link target=_blank href=https://www.apache.org/foundation/thanks.html>Thanks</a></li><li><a class=navbar-dropdown-menu-link target=_blank href=https://www.apache.org/foundation/sponsorship.html>Sponsorship</a></li><li><a class=navbar-dropdown-menu-link target=_blank href=https://www.apache.org/foundation/policies/conduct>Code of Conduct</a></li></ul></li></div><div class="searchBar disappear"><script>(function(){var t,n="012923275103528129024:4emlchv9wzi",e=document.createElement("script");e.type="text/javascript",e.async=!0,e.src="https://cse.google.com/cse.js?cx="+n,t=document.getElementsByTagName("script")[0],t.parentNode.insertBefore(e,t)})()</script><gcse:search></gcse:search> |
| <a type=button onclick=endSearch()><svg xmlns="http://www.w3.org/2000/svg" width="25" height="25" fill="none" viewBox="0 0 25 25"><path stroke="#ff6d00" stroke-linecap="round" stroke-linejoin="round" stroke-width="2.75" d="M21.122 20.827 4.727 4.432M21.122 4.43 4.727 20.827"/></svg></a></div></div></nav><div class=header-push></div><div class="top-banners swiper"><div class=swiper-wrapper><div class=swiper-slide><a href=https://tour.beam.apache.org><img class=banner-img-desktop src=/images/banners/tour-of-beam/tour-of-beam-desktop.png alt="Start Tour of Beam"> |
| <img class=banner-img-mobile src=/images/banners/tour-of-beam/tour-of-beam-mobile.png alt="Start Tour of Beam"></a></div><div class=swiper-slide><a href=https://beam.apache.org/documentation/ml/overview/><img class=banner-img-desktop src=/images/banners/machine-learning/machine-learning-desktop.jpg alt="Machine Learning"> |
| <img class=banner-img-mobile src=/images/banners/machine-learning/machine-learning-mobile.jpg alt="Machine Learning"></a></div></div><div class=swiper-pagination></div><div class=swiper-button-prev></div><div class=swiper-button-next></div></div><script src=/js/swiper-bundle.min.min.e0e8f81b0b15728d35ff73c07f42ddbb17a108d6f23df4953cb3e60df7ade675.js></script> |
| <script src=/js/sliders/top-banners.min.afa7d0a19acf7a3b28ca369490b3d401a619562a2a4c9612577be2f66a4b9855.js></script> |
| <script>function showSearch(){addPlaceholder();var e,t=document.querySelector(".searchBar");t.classList.remove("disappear"),e=document.querySelector("#iconsBar"),e.classList.add("disappear")}function addPlaceholder(){$("input:text").attr("placeholder","What are you looking for?")}function endSearch(){var e,t=document.querySelector(".searchBar");t.classList.add("disappear"),e=document.querySelector("#iconsBar"),e.classList.remove("disappear")}function blockScroll(){$("body").toggleClass("fixedPosition")}function openMenu(){addPlaceholder(),blockScroll()}</script><div class="clearfix container-main-content"><div class="section-nav closed" data-offset-top=90 data-offset-bottom=500><span class="section-nav-back glyphicon glyphicon-menu-left"></span><nav><ul class=section-nav-list data-section-nav><li><span class=section-nav-list-main-title>Languages</span></li><li><span class=section-nav-list-title>Java</span><ul class=section-nav-list><li><a href=/documentation/sdks/java/>Java SDK overview</a></li><li><a href=https://beam.apache.org/releases/javadoc/2.55.1/ target=_blank>Java SDK API reference <img src=/images/external-link-icon.png width=14 height=14 alt="External link."></a></li><li><a href=/documentation/sdks/java-dependencies/>Java SDK dependencies</a></li><li><a href=/documentation/sdks/java-extensions/>Java SDK extensions</a></li><li><a href=/documentation/sdks/java-thirdparty/>Java 3rd party extensions</a></li><li><a href=/documentation/sdks/java/testing/nexmark/>Nexmark benchmark suite</a></li><li><a href=/documentation/sdks/java/testing/tpcds/>TPC-DS benchmark suite</a></li><li><a href=/documentation/sdks/java-multi-language-pipelines/>Java multi-language pipelines quickstart</a></li></ul></li><li><span class=section-nav-list-title>Python</span><ul class=section-nav-list><li><a href=/documentation/sdks/python/>Python SDK overview</a></li><li><a href=https://beam.apache.org/releases/pydoc/2.55.1/ target=_blank>Python SDK API reference <img src=/images/external-link-icon.png width=14 height=14 alt="External link."></a></li><li><a href=/documentation/sdks/python-dependencies/>Python SDK dependencies</a></li><li><a href=/documentation/sdks/python-streaming/>Python streaming pipelines</a></li><li><a href=/documentation/sdks/python-type-safety/>Ensuring Python type safety</a></li><li><a href=/documentation/sdks/python-machine-learning/>Machine Learning</a></li><li><a href=/documentation/sdks/python-pipeline-dependencies/>Managing pipeline dependencies</a></li><li><a href=/documentation/sdks/python-multi-language-pipelines/>Python multi-language pipelines quickstart</a></li><li><a href=/documentation/sdks/python-unrecoverable-errors/>Python Unrecoverable Errors</a></li></ul></li><li><span class=section-nav-list-title>Go</span><ul class=section-nav-list><li><a href=/documentation/sdks/go/>Go SDK overview</a></li><li><a href=https://pkg.go.dev/github.com/apache/beam/sdks/v2/go/pkg/beam target=_blank>Go SDK API reference <img src=/images/external-link-icon.png width=14 height=14 alt="External link."></a><li><a href=/documentation/sdks/go-dependencies/>Go SDK dependencies</a></li><li><a href=/documentation/sdks/go-cross-compilation/>Cross compilation</a></li></li></ul></li><li><span class=section-nav-list-title>Typescript</span><ul class=section-nav-list><li><a href=/documentation/sdks/typescript/>Typescript SDK overview</a></li><li><a href=https://beam.apache.org/releases/typedoc/current/ target=_blank>Typescript SDK API reference <img src=/images/external-link-icon.png width=14 height=14 alt="External link."></a></li></ul></li><li><span class=section-nav-list-title>Scala</span><ul class=section-nav-list><li><a href=/documentation/sdks/scala/>Scio</a></li><li><a href=https://spotify.github.io/scio/api/com/spotify/scio/index.html target=_blank>Scio SDK API reference <img src=/images/external-link-icon.png width=14 height=14 alt="External link."></a></li></ul></li><li><span class=section-nav-list-title>Yaml</span><ul class=section-nav-list><li><a href=/documentation/sdks/yaml/>Yaml overview</a></li><li><a href=/documentation/sdks/yaml-udf/>Yaml User Defined Functions</a></li><li><a href=/documentation/sdks/yaml-combine/>Yaml Aggregation</a></li><li><a href=/documentation/sdks/yaml-errors/>Error handling</a></li><li><a href=/documentation/sdks/yaml-inline-python/>Inlining Python</a></li><li><a href=https://beam.apache.org/releases/yamldoc/current/ target=_blank>YAML API reference <img src=/images/external-link-icon.png width=14 height=14 alt="External link."></a></ul></li><li><span class=section-nav-list-title>SQL</span><ul class=section-nav-list><li><a href=/documentation/dsls/sql/overview/>Overview</a></li><li><a href=/documentation/dsls/sql/walkthrough/>Walkthrough</a></li><li><a href=/documentation/dsls/sql/shell/>Shell</a></li><li class=section-nav-item--collapsible><span class=section-nav-list-title>Apache Calcite dialect</span><ul class=section-nav-list><li><a href=/documentation/dsls/sql/calcite/overview/>Calcite support overview</a></li><li><a href=/documentation/dsls/sql/calcite/query-syntax/>Query syntax</a></li><li><a href=/documentation/dsls/sql/calcite/lexical/>Lexical structure</a></li><li><a href=/documentation/dsls/sql/calcite/data-types/>Data types</a></li><li><a href=/documentation/dsls/sql/calcite/scalar-functions/>Scalar functions</a></li><li><a href=/documentation/dsls/sql/calcite/aggregate-functions/>Aggregate functions</a></li></ul></li><li class=section-nav-item--collapsible><span class=section-nav-list-title>ZetaSQL dialect</span><ul class=section-nav-list><li><a href=/documentation/dsls/sql/zetasql/overview/>ZetaSQL support overview</a></li><li><a href=/documentation/dsls/sql/zetasql/syntax/>Function call rules</a></li><li><a href=/documentation/dsls/sql/zetasql/conversion-rules/>Conversion rules</a></li><li><a href=/documentation/dsls/sql/zetasql/query-syntax/>Query syntax</a></li><li><a href=/documentation/dsls/sql/zetasql/lexical/>Lexical structure</a></li><li><a href=/documentation/dsls/sql/zetasql/data-types/>Data types</a></li><li><a href=/documentation/dsls/sql/zetasql/operators/>Operators</a></li><li class=section-nav-item--collapsible><span class=section-nav-list-title>Scalar functions</span><ul class=section-nav-list><li><a href=/documentation/dsls/sql/zetasql/string-functions/>String functions</a></li><li><a href=/documentation/dsls/sql/zetasql/math-functions/>Mathematical functions</a></li><li><a href=/documentation/dsls/sql/zetasql/conditional-expressions/>Conditional expressions</a></li></ul></li><li><a href=/documentation/dsls/sql/zetasql/aggregate-functions/>Aggregate functions</a></li></ul></li><li class=section-nav-item--collapsible><span class=section-nav-list-title>Beam SQL extensions</span><ul class=section-nav-list><li><a href=/documentation/dsls/sql/extensions/create-external-table/>CREATE EXTERNAL TABLE</a></li><li><a href=/documentation/dsls/sql/extensions/windowing-and-triggering/>Windowing & triggering</a></li><li><a href=/documentation/dsls/sql/extensions/joins/>Joins</a></li><li><a href=/documentation/dsls/sql/extensions/user-defined-functions/>User-defined functions</a></li><li><a href=/documentation/dsls/sql/extensions/set/>SET pipeline options</a></li></ul></li></ul></li><li><span class=section-nav-list-title>DataFrames</span><ul class=section-nav-list><li><a href=/documentation/dsls/dataframes/overview/>Overview</a></li><li><a href=/documentation/dsls/dataframes/differences-from-pandas/>Differences from pandas</a></li><li><a href=https://github.com/apache/beam/tree/master/sdks/python/apache_beam/examples/dataframe target=_blank>Example pipelines <img src=/images/external-link-icon.png width=14 height=14 alt="External link."></a></li><li><a href=https://beam.apache.org/releases/pydoc/2.55.1/apache_beam.dataframe.html target=_blank>DataFrame API reference <img src=/images/external-link-icon.png width=14 height=14 alt="External link."></a></li></ul></li></ul></nav></div><nav class="page-nav clearfix" data-offset-top=90 data-offset-bottom=500><nav id=TableOfContents><ul><li><a href=#casting>Casting</a></li><li><a href=#coercion>Coercion</a></li></ul></nav></nav><div class="body__contained body__section-nav"><h1 id=beam-zetasql-conversion-rules>Beam ZetaSQL conversion rules</h1><p>Conversion includes, but is not limited to, casting and coercion:</p><ul><li>Casting is explicit conversion and uses the <code>CAST()</code> function.</li><li>Coercion is implicit conversion, which Beam SQL performs |
| automatically under the conditions described below.</li></ul><p>The table below summarizes all possible <code>CAST</code>s and coercions. “Coercion To” applies to all <em>expressions</em> of a given data type (e.g. a column).</p><div class=table-wrapper><table class=table-wrapper--equal-p><thead><tr><th>From Type</th><th>CAST to</th><th>Coercion To</th></tr></thead><tbody><tr><td>INT64</td><td><span>INT64</span><br><span>FLOAT64</span><br><span>STRING</span><br></td><td><span>FLOAT64</span><br></td></tr><tr><td>FLOAT64</td><td><span>FLOAT64</span><br></td><td> </td></tr><tr><td>BOOL</td><td><span>BOOL</span><br></td><td> </td></tr><tr><td>STRING</td><td><span>INT64</span><br><span>STRING</span><br><span>BYTES</span><br><span>TIMESTAMP</span><br></td><td> </td></tr><tr><td>BYTES</td><td><span>BYTES</span><br><span>STRING</span><br></td><td> </td></tr><tr><td>TIMESTAMP</td><td><span>STRING</span><br><span>TIMESTAMP</span><br></td><td> </td></tr><tr><td>ARRAY</td><td>ARRAY</td><td> </td></tr><tr><td>STRUCT</td><td>STRUCT</td><td> </td></tr></tbody></table></div><h2 id=casting>Casting</h2><p>Syntax:</p><pre tabindex=0><code>CAST(expr AS typename) |
| </code></pre><p>Cast syntax is used in a query to indicate that the result type of an |
| expression should be converted to some other type.</p><p>Example:</p><pre tabindex=0><code>CAST(x=1 AS STRING) |
| </code></pre><p>This results in <code>"true"</code> if <code>x</code> is <code>1</code>, <code>"false"</code> for any other non-<code>NULL</code> |
| value, and <code>NULL</code> if <code>x</code> is <code>NULL</code>.</p><p>Casts between supported types that do not successfully map from the original |
| value to the target domain produce runtime errors. For example, casting |
| BYTES to STRING where the |
| byte sequence is not valid UTF-8 results in a runtime error.</p><p>When casting an expression <code>x</code> of the following types, these rules apply:</p><div class=table-wrapper><table class=table-wrapper--equal-p><tr><th>From</th><th>To</th><th>Rule(s) when casting <code>x</code></th></tr><tr><td>INT64</td><td>FLOAT64</td><td>Returns a close but potentially not exact |
| FLOAT64 |
| value.</td></tr><tr><td>FLOAT64</td><td>STRING</td><td>Returns an approximate string representation.<br></td></tr><tr><td>STRING</td><td>BYTES</td><td>STRINGs are cast to BYTES using UTF-8 encoding. For example, the STRING "©", |
| when cast to BYTES, would become a 2-byte sequence with the hex values C2 and |
| A9.</td></tr><tr><td>BYTES</td><td>STRING</td><td>Returns <code>x</code> interpreted as a UTF-8 STRING.<br>For example, the BYTES literal |
| <code>b'\xc2\xa9'</code>, when cast to STRING, is interpreted as UTF-8 and |
| becomes the unicode character "©".<br>An error occurs if <code>x</code> is not valid UTF-8.</td></tr><tr><td>ARRAY</td><td>ARRAY</td><td>Must be the exact same ARRAY type.</td></tr><tr><td>STRUCT</td><td>STRUCT</td><td>Allowed if the following conditions are met:<br><ol><li>The two STRUCTs have the same number of fields.</li><li>The original STRUCT field types can be explicitly cast to the corresponding |
| target STRUCT field types (as defined by field order, not field name).</li></ol></td></tr></table></div><h2 id=coercion>Coercion</h2><p>Beam SQL coerces the result type of an expression to another type if |
| needed to match function signatures. For example, if function func() is defined to take a single argument of type INT64 and an expression is used as an argument that has a result type of FLOAT64, then the result of the expression will be coerced to INT64 type before func() is computed.</p></div></div><footer class=footer><div class=footer__contained><div class=footer__cols><div class="footer__cols__col footer__cols__col__logos"><div class=footer__cols__col__logo><img src=/images/beam_logo_circle.svg class=footer__logo alt="Beam logo"></div><div class=footer__cols__col__logo><img src=/images/apache_logo_circle.svg class=footer__logo alt="Apache logo"></div></div><div class=footer-wrapper><div class=wrapper-grid><div class=footer__cols__col><div class=footer__cols__col__title>Start</div><div class=footer__cols__col__link><a href=/get-started/beam-overview/>Overview</a></div><div class=footer__cols__col__link><a href=/get-started/quickstart-java/>Quickstart (Java)</a></div><div class=footer__cols__col__link><a href=/get-started/quickstart-py/>Quickstart (Python)</a></div><div class=footer__cols__col__link><a href=/get-started/quickstart-go/>Quickstart (Go)</a></div><div class=footer__cols__col__link><a href=/get-started/downloads/>Downloads</a></div></div><div class=footer__cols__col><div class=footer__cols__col__title>Docs</div><div class=footer__cols__col__link><a href=/documentation/programming-guide/>Concepts</a></div><div class=footer__cols__col__link><a href=/documentation/pipelines/design-your-pipeline/>Pipelines</a></div><div class=footer__cols__col__link><a href=/documentation/runners/capability-matrix/>Runners</a></div></div><div class=footer__cols__col><div class=footer__cols__col__title>Community</div><div class=footer__cols__col__link><a href=/contribute/>Contribute</a></div><div class=footer__cols__col__link><a href=https://projects.apache.org/committee.html?beam target=_blank>Team<img src=/images/external-link-icon.png width=14 height=14 alt="External link."></a></div><div class=footer__cols__col__link><a href=/community/presentation-materials/>Media</a></div><div class=footer__cols__col__link><a href=/community/in-person/>Events/Meetups</a></div><div class=footer__cols__col__link><a href=/community/contact-us/>Contact Us</a></div></div><div class=footer__cols__col><div class=footer__cols__col__title>Resources</div><div class=footer__cols__col__link><a href=/blog/>Blog</a></div><div class=footer__cols__col__link><a href=https://github.com/apache/beam>GitHub</a></div></div></div><div class=footer__bottom>© |
| <a href=https://www.apache.org>The Apache Software Foundation</a> |
| | <a href=/privacy_policy>Privacy Policy</a> |
| | <a href=/feed.xml>RSS Feed</a><br><br>Apache Beam, Apache, Beam, the Beam logo, and the Apache feather logo are either registered trademarks or trademarks of The Apache Software Foundation. All other products or name brands are trademarks of their respective holders, including The Apache Software Foundation.</div></div><div class="footer__cols__col footer__cols__col__logos"><div class=footer__cols__col--group><div class=footer__cols__col__logo><a href=https://github.com/apache/beam><img src=/images/logos/social-icons/github-logo-150.png class=footer__logo alt="Github logo"></a></div><div class=footer__cols__col__logo><a href=https://www.linkedin.com/company/apache-beam/><img src=/images/logos/social-icons/linkedin-logo-150.png class=footer__logo alt="Linkedin logo"></a></div></div><div class=footer__cols__col--group><div class=footer__cols__col__logo><a href=https://twitter.com/apachebeam><img src=/images/logos/social-icons/twitter-logo-150.png class=footer__logo alt="Twitter logo"></a></div><div class=footer__cols__col__logo><a href=https://www.youtube.com/channel/UChNnb_YO_7B0HlW6FhAXZZQ><img src=/images/logos/social-icons/youtube-logo-150.png class=footer__logo alt="Youtube logo"></a></div></div></div></div></div></footer></body></html> |
