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| <h1 class="title">CREATE FUNCTION (SQL)</h1> |
| |
| |
| <h3 id="description">Description</h3> |
| <p>The <code class="language-plaintext highlighter-rouge">CREATE FUNCTION</code> statement creates a SQL function that can be used in SQL statements. The function can be temporary or permanent, and can return either a scalar value or a table result. The function body can be defined either a SQL expression or a query.</p> |
| |
| <p>When <code class="language-plaintext highlighter-rouge">TEMPORARY</code> is specified, the function is only available for the current session. Otherwise, it is persisted in the catalog and available across sessions. The <code class="language-plaintext highlighter-rouge">OR REPLACE</code> option allows updating an existing function definition, while <code class="language-plaintext highlighter-rouge">IF NOT EXISTS</code> prevents errors when creating a function that already exists.</p> |
| |
| <p>The function parameters must be specified with their data types. The return type can be either a scalar data type or a table with an optional schema definition.</p> |
| |
| <h3 id="syntax">Syntax</h3> |
| |
| <div class="language-sql highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="k">CREATE</span> <span class="p">[</span><span class="k">OR</span> <span class="k">REPLACE</span><span class="p">]</span> <span class="p">[</span><span class="k">TEMPORARY</span><span class="p">]</span> <span class="k">FUNCTION</span> <span class="p">[</span><span class="n">IF</span> <span class="k">NOT</span> <span class="k">EXISTS</span><span class="p">]</span> |
| <span class="n">function_name</span> <span class="p">(</span> <span class="p">[</span> <span class="n">function_parameter</span> <span class="p">[,</span> <span class="p">...]</span> <span class="p">]</span> <span class="p">)</span> |
| <span class="p">{</span> <span class="p">[</span> <span class="k">RETURNS</span> <span class="n">data_type</span> <span class="p">]</span> <span class="o">|</span> |
| <span class="k">RETURNS</span> <span class="k">TABLE</span> <span class="p">[</span> <span class="p">(</span> <span class="n">column_spec</span> <span class="p">[,</span> <span class="p">...])</span> <span class="p">]</span> <span class="p">}</span> |
| <span class="p">[</span> <span class="n">characteristic</span> <span class="p">[...]</span> <span class="p">]</span> |
| <span class="k">RETURN</span> <span class="p">{</span> <span class="n">expression</span> <span class="o">|</span> <span class="n">query</span> <span class="p">}</span> |
| |
| <span class="n">function_parameter</span> |
| <span class="n">parameter_name</span> <span class="n">data_type</span> <span class="p">[</span><span class="k">DEFAULT</span> <span class="n">default_expression</span><span class="p">]</span> <span class="p">[</span><span class="k">COMMENT</span> <span class="n">parameter_comment</span><span class="p">]</span> |
| |
| <span class="n">column_spec</span> |
| <span class="k">column_name</span> <span class="n">data_type</span> <span class="p">[</span><span class="k">COMMENT</span> <span class="n">column_comment</span><span class="p">]</span> |
| |
| <span class="n">characteristic</span> |
| <span class="p">{</span> <span class="k">LANGUAGE</span> <span class="k">SQL</span> <span class="o">|</span> |
| <span class="p">[</span><span class="k">NOT</span><span class="p">]</span> <span class="k">DETERMINISTIC</span> <span class="o">|</span> |
| <span class="k">COMMENT</span> <span class="n">function_comment</span> <span class="o">|</span> |
| <span class="p">[</span><span class="k">CONTAINS</span> <span class="k">SQL</span> <span class="o">|</span> <span class="k">READS</span> <span class="k">SQL</span> <span class="k">DATA</span><span class="p">]</span> <span class="p">}</span> |
| </code></pre></div></div> |
| |
| <h3 id="parameters">Parameters</h3> |
| |
| <ul> |
| <li> |
| <p><strong>OR REPLACE</strong></p> |
| |
| <p>If specified, the function with the same name and signature (number of parameters and parameter types) is replaced. You cannot replace an existing function with a different signature or a procedure. This is mainly useful to update the function body and the return type of the function. You cannot specify this parameter with <code class="language-plaintext highlighter-rouge">IF NOT EXISTS</code>.</p> |
| </li> |
| <li> |
| <p><strong>TEMPORARY</strong></p> |
| |
| <p>The scope of the function being created. When you specify <code class="language-plaintext highlighter-rouge">TEMPORARY</code>, the created function is valid and visible in the current session. No persistent entry is made in the catalog.</p> |
| </li> |
| <li> |
| <p><strong>IF NOT EXISTS</strong></p> |
| |
| <p>If specified, creates the function only when it does not exist. The creation of the function succeeds (no error is thrown) if the specified function already exists in the system. You cannot specify this parameter with <code class="language-plaintext highlighter-rouge">OR REPLACE</code>.</p> |
| </li> |
| <li> |
| <p><strong>function_name</strong></p> |
| |
| <p>A name for the function. For a permanent function, you can optionally qualify the function name, or it will be created under the current catalog and namespace. |
| If the name is not qualified the permanent function is created in the current schema.</p> |
| |
| <p><strong>Syntax:</strong> <code class="language-plaintext highlighter-rouge">[ database_name. ] function_name</code></p> |
| </li> |
| <li> |
| <p><strong>function_parameter</strong></p> |
| |
| <p>Specifies a parameter of the function.</p> |
| |
| <ul> |
| <li> |
| <p><strong><a href="sql-ref-identifier.md">parameter_name</a></strong></p> |
| |
| <p>The parameter name must be unique within the function.</p> |
| </li> |
| <li> |
| <p><strong><a href="sql-ref-datatypes.md">data_type</a></strong></p> |
| |
| <p>Any supported data type.</p> |
| </li> |
| <li> |
| <p><strong>DEFAULT default_expression</strong></p> |
| |
| <p>An optional default to be used when a function invocation does not assign an argument to the parameter. |
| <code class="language-plaintext highlighter-rouge">default_expression</code> must be castable to <code class="language-plaintext highlighter-rouge">data_type</code>. |
| The expression must not reference another parameter or contain a subquery.</p> |
| |
| <p>When you specify a default for one parameter, all following parameters must also have a default.</p> |
| </li> |
| <li> |
| <p><strong>COMMENT comment</strong></p> |
| |
| <p>An optional description of the parameter. <code class="language-plaintext highlighter-rouge">comment</code> must be a <code class="language-plaintext highlighter-rouge">STRING</code> literal.</p> |
| </li> |
| </ul> |
| </li> |
| <li> |
| <p><strong>RETURNS <a href="sql-ref-datatypes.md">data_type</a></strong></p> |
| |
| <p>The return data type of the scalar function. This clause is optional. The data type will be derived from the SQL function body if it is not provided.</p> |
| </li> |
| <li> |
| <p><strong>RETURNS TABLE [ (column_spec [,…] ) ]</strong></p> |
| |
| <p>This clause marks the function as a table function. |
| Optionally it also specifies the signature of the result of the table function. |
| If no column_spec is specified it will be derived from the body of the SQL UDF.</p> |
| |
| <ul> |
| <li> |
| <p><strong><a href="sql-ref-identifier.md">column_name</a></strong></p> |
| |
| <p>The column name must be unique within the signature.</p> |
| </li> |
| <li> |
| <p><strong><a href="sql-ref-datatypes.md">data_type</a></strong></p> |
| |
| <p>Any supported data type.</p> |
| </li> |
| <li> |
| <p><strong>COMMENT column_comment</strong></p> |
| |
| <p>An optional description of the column. <code class="language-plaintext highlighter-rouge">comment</code> must be a <code class="language-plaintext highlighter-rouge">STRING</code> literal.</p> |
| </li> |
| </ul> |
| </li> |
| <li> |
| <table> |
| <tbody> |
| <tr> |
| <td>**RETURN { expression</td> |
| <td>query }**</td> |
| </tr> |
| </tbody> |
| </table> |
| |
| <p>The body of the function. For a scalar function, it can either be a query or an expression. For a table function, it can only be a query. The expression cannot contain:</p> |
| |
| <ul> |
| <li><a href="sql-ref-functions-builtin.md#aggregate-functions">Aggregate functions</a></li> |
| <li><a href="sql-ref-functions-builtin.md#analytic-window-functions">Window functions</a></li> |
| <li><a href="sql-ref-functions-builtin.md#ranking-window-functions">Ranking functions</a></li> |
| <li>Row producing functions such as <code class="language-plaintext highlighter-rouge">explode</code></li> |
| </ul> |
| |
| <p>Within the body of the function you can refer to parameter by its unqualified name or by qualifying the parameter with the function name.</p> |
| </li> |
| <li> |
| <p><strong>characteristic</strong></p> |
| |
| <p>All characteristic clauses are optional. |
| You can specify any number of them in any order, but you can specify each clause only once.</p> |
| |
| <ul> |
| <li> |
| <p><strong>LANGUAGE SQL</strong></p> |
| |
| <p>The language of the function implementation.</p> |
| </li> |
| <li> |
| <p><strong>[NOT] DETERMINISTIC</strong></p> |
| |
| <p>Whether the function is deterministic. |
| A function is deterministic when it returns only one result for a given set of arguments. |
| You may mark a function as <code class="language-plaintext highlighter-rouge">DETERMINISTIC</code> when its body is not and vice versa. |
| A reason for this may be to encourage or discourage query optimizations such as constant |
| folding or query caching. |
| If you do not specify ths option it is derived from the function body.</p> |
| </li> |
| <li> |
| <p><strong>COMMENT function_comment</strong></p> |
| |
| <p>A comment for the function. <code class="language-plaintext highlighter-rouge">function_comment</code> must be String literal.</p> |
| </li> |
| <li> |
| <p><strong>CONTAINS SQL</strong> or <strong>READS SQL DATA</strong></p> |
| |
| <p>Whether a function reads data directly or indirectly from a table or a view. |
| When the function reads SQL data, you cannot specify <code class="language-plaintext highlighter-rouge">CONTAINS SQL</code>. |
| If you don’t specify either clause, the property is derived from the function body.</p> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| |
| <h2 id="examples">Examples</h2> |
| |
| <h3 id="create-and-use-a-sql-scalar-function">Create and use a SQL scalar function</h3> |
| |
| <div class="language-sql highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="o">></span> <span class="k">CREATE</span> <span class="k">VIEW</span> <span class="n">t</span><span class="p">(</span><span class="n">c1</span><span class="p">,</span> <span class="n">c2</span><span class="p">)</span> <span class="k">AS</span> <span class="k">VALUES</span> <span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="mi">1</span><span class="p">),</span> <span class="p">(</span><span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">);</span> |
| |
| <span class="c1">-- Create a temporary function with no parameter.</span> |
| <span class="o">></span> <span class="k">CREATE</span> <span class="k">TEMPORARY</span> <span class="k">FUNCTION</span> <span class="n">hello</span><span class="p">()</span> <span class="k">RETURNS</span> <span class="n">STRING</span> |
| <span class="k">RETURN</span> <span class="s1">'Hello World!'</span><span class="p">;</span> |
| |
| <span class="o">></span> <span class="k">SELECT</span> <span class="n">hello</span><span class="p">();</span> |
| <span class="n">Hello</span> <span class="n">World</span><span class="o">!</span> |
| |
| <span class="c1">-- Create a permanent function with parameters.</span> |
| <span class="o">></span> <span class="k">CREATE</span> <span class="k">FUNCTION</span> <span class="n">area</span><span class="p">(</span><span class="n">x</span> <span class="nb">DOUBLE</span><span class="p">,</span> <span class="n">y</span> <span class="nb">DOUBLE</span><span class="p">)</span> <span class="k">RETURNS</span> <span class="nb">DOUBLE</span> <span class="k">RETURN</span> <span class="n">x</span> <span class="o">*</span> <span class="n">y</span><span class="p">;</span> |
| |
| <span class="c1">-- Use a SQL function in the SELECT clause of a query.</span> |
| <span class="o">></span> <span class="k">SELECT</span> <span class="n">area</span><span class="p">(</span><span class="n">c1</span><span class="p">,</span> <span class="n">c2</span><span class="p">)</span> <span class="k">AS</span> <span class="n">area</span> <span class="k">FROM</span> <span class="n">t</span><span class="p">;</span> |
| <span class="mi">1</span><span class="p">.</span><span class="mi">0</span> |
| <span class="mi">1</span><span class="p">.</span><span class="mi">0</span> |
| |
| <span class="c1">-- Use a SQL function in the WHERE clause of a query.</span> |
| <span class="o">></span> <span class="k">SELECT</span> <span class="o">*</span> <span class="k">FROM</span> <span class="n">t</span> <span class="k">WHERE</span> <span class="n">area</span><span class="p">(</span><span class="n">c1</span><span class="p">,</span> <span class="n">c2</span><span class="p">)</span> <span class="o">></span> <span class="mi">0</span><span class="p">;</span> |
| <span class="mi">1</span> <span class="mi">2</span> |
| |
| <span class="c1">-- Compose SQL functions.</span> |
| <span class="o">></span> <span class="k">CREATE</span> <span class="k">FUNCTION</span> <span class="n">square</span><span class="p">(</span><span class="n">x</span> <span class="nb">DOUBLE</span><span class="p">)</span> <span class="k">RETURNS</span> <span class="nb">DOUBLE</span> <span class="k">RETURN</span> <span class="n">area</span><span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">x</span><span class="p">);</span> |
| |
| <span class="o">></span> <span class="k">SELECT</span> <span class="n">c1</span><span class="p">,</span> <span class="n">square</span><span class="p">(</span><span class="n">c1</span><span class="p">)</span> <span class="k">AS</span> <span class="n">square</span> <span class="k">FROM</span> <span class="n">t</span><span class="p">;</span> |
| <span class="mi">0</span> <span class="mi">0</span><span class="p">.</span><span class="mi">0</span> |
| <span class="mi">1</span> <span class="mi">1</span><span class="p">.</span><span class="mi">0</span> |
| |
| <span class="c1">-- Create a non-deterministic function</span> |
| <span class="o">></span> <span class="k">CREATE</span> <span class="k">FUNCTION</span> <span class="n">roll_dice</span><span class="p">()</span> |
| <span class="k">RETURNS</span> <span class="nb">INT</span> |
| <span class="k">NOT</span> <span class="k">DETERMINISTIC</span> |
| <span class="k">CONTAINS</span> <span class="k">SQL</span> |
| <span class="k">COMMENT</span> <span class="s1">'Roll a single 6 sided die'</span> |
| <span class="k">RETURN</span> <span class="p">(</span><span class="n">rand</span><span class="p">()</span> <span class="o">*</span> <span class="mi">6</span><span class="p">)::</span><span class="nb">INT</span> <span class="o">+</span> <span class="mi">1</span><span class="p">;</span> |
| <span class="c1">-- Roll a single 6-sided die</span> |
| <span class="o">></span> <span class="k">SELECT</span> <span class="n">roll_dice</span><span class="p">();</span> |
| <span class="mi">3</span> |
| </code></pre></div></div> |
| |
| <h3 id="create-a-sql-table-function">Create a SQL table function</h3> |
| |
| <div class="language-sql highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="c1">-- Produce all weekdays between two dates</span> |
| <span class="o">></span> <span class="k">CREATE</span> <span class="k">FUNCTION</span> <span class="n">weekdays</span><span class="p">(</span><span class="k">start</span> <span class="nb">DATE</span><span class="p">,</span> <span class="k">end</span> <span class="nb">DATE</span><span class="p">)</span> |
| <span class="k">RETURNS</span> <span class="k">TABLE</span><span class="p">(</span><span class="n">day_of_week</span> <span class="n">STRING</span><span class="p">,</span> <span class="k">day</span> <span class="nb">DATE</span><span class="p">)</span> |
| <span class="k">RETURN</span> <span class="k">SELECT</span> <span class="k">extract</span><span class="p">(</span><span class="n">DAYOFWEEK_ISO</span> <span class="k">FROM</span> <span class="k">day</span><span class="p">),</span> <span class="k">day</span> |
| <span class="k">FROM</span> <span class="p">(</span><span class="k">SELECT</span> <span class="n">sequence</span><span class="p">(</span><span class="n">weekdays</span><span class="p">.</span><span class="k">start</span><span class="p">,</span> <span class="n">weekdays</span><span class="p">.</span><span class="k">end</span><span class="p">))</span> <span class="k">AS</span> <span class="n">T</span><span class="p">(</span><span class="n">days</span><span class="p">)</span> |
| <span class="k">LATERAL</span> <span class="k">VIEW</span> <span class="n">explode</span><span class="p">(</span><span class="n">days</span><span class="p">)</span> <span class="k">AS</span> <span class="k">day</span> |
| <span class="k">WHERE</span> <span class="k">extract</span><span class="p">(</span><span class="n">DAYOFWEEK_ISO</span> <span class="k">FROM</span> <span class="k">day</span><span class="p">)</span> <span class="k">BETWEEN</span> <span class="mi">1</span> <span class="k">AND</span> <span class="mi">5</span><span class="p">;</span> |
| |
| <span class="c1">-- Return all weekdays</span> |
| <span class="o">></span> <span class="k">SELECT</span> <span class="n">weekdays</span><span class="p">.</span><span class="n">day_of_week</span><span class="p">,</span> <span class="k">day</span> |
| <span class="k">FROM</span> <span class="n">weekdays</span><span class="p">(</span><span class="nb">DATE</span><span class="s1">'2022-01-01'</span><span class="p">,</span> <span class="nb">DATE</span><span class="s1">'2022-01-14'</span><span class="p">);</span> |
| <span class="mi">1</span> <span class="mi">2022</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">03</span> |
| <span class="mi">2</span> <span class="mi">2022</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">04</span> |
| <span class="mi">3</span> <span class="mi">2022</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">05</span> |
| <span class="mi">4</span> <span class="mi">2022</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">06</span> |
| <span class="mi">5</span> <span class="mi">2022</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">07</span> |
| <span class="mi">1</span> <span class="mi">2022</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">10</span> |
| <span class="mi">2</span> <span class="mi">2022</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">11</span> |
| <span class="mi">3</span> <span class="mi">2022</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">12</span> |
| <span class="mi">4</span> <span class="mi">2022</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">13</span> |
| <span class="mi">5</span> <span class="mi">2022</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">14</span> |
| |
| <span class="c1">-- Return weekdays for date ranges originating from a LATERAL correlation</span> |
| <span class="o">></span> <span class="k">SELECT</span> <span class="n">weekdays</span><span class="p">.</span><span class="o">*</span> |
| <span class="k">FROM</span> <span class="k">VALUES</span> <span class="p">(</span><span class="nb">DATE</span><span class="s1">'2020-01-01'</span><span class="p">),</span> |
| <span class="p">(</span><span class="nb">DATE</span><span class="s1">'2021-01-01'</span><span class="p">),</span> |
| <span class="p">(</span><span class="nb">DATE</span><span class="s1">'2022-01-01'</span><span class="p">)</span> <span class="k">AS</span> <span class="n">starts</span><span class="p">(</span><span class="k">start</span><span class="p">),</span> |
| <span class="k">LATERAL</span> <span class="n">weekdays</span><span class="p">(</span><span class="k">start</span><span class="p">,</span> <span class="k">start</span> <span class="o">+</span> <span class="n">INTERVAL</span> <span class="s1">'7'</span> <span class="n">DAYS</span><span class="p">);</span> |
| <span class="mi">3</span> <span class="mi">2020</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">01</span> |
| <span class="mi">4</span> <span class="mi">2020</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">02</span> |
| <span class="mi">5</span> <span class="mi">2020</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">03</span> |
| <span class="mi">1</span> <span class="mi">2020</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">06</span> |
| <span class="mi">2</span> <span class="mi">2020</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">07</span> |
| <span class="mi">3</span> <span class="mi">2020</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">08</span> |
| <span class="mi">5</span> <span class="mi">2021</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">01</span> |
| <span class="mi">1</span> <span class="mi">2021</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">04</span> |
| <span class="mi">2</span> <span class="mi">2021</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">05</span> |
| <span class="mi">3</span> <span class="mi">2021</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">06</span> |
| <span class="mi">4</span> <span class="mi">2021</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">07</span> |
| <span class="mi">5</span> <span class="mi">2021</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">08</span> |
| <span class="mi">1</span> <span class="mi">2022</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">03</span> |
| <span class="mi">2</span> <span class="mi">2022</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">04</span> |
| <span class="mi">3</span> <span class="mi">2022</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">05</span> |
| <span class="mi">4</span> <span class="mi">2022</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">06</span> |
| <span class="mi">5</span> <span class="mi">2022</span><span class="o">-</span><span class="mi">01</span><span class="o">-</span><span class="mi">07</span> |
| </code></pre></div></div> |
| |
| <h3 id="replace-a-sql-function">Replace a SQL function</h3> |
| |
| <div class="language-sql highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="c1">-- Replace a SQL scalar function.</span> |
| <span class="o">></span> <span class="k">CREATE</span> <span class="k">OR</span> <span class="k">REPLACE</span> <span class="k">FUNCTION</span> <span class="n">square</span><span class="p">(</span><span class="n">x</span> <span class="nb">DOUBLE</span><span class="p">)</span> <span class="k">RETURNS</span> <span class="nb">DOUBLE</span> <span class="k">RETURN</span> <span class="n">x</span> <span class="o">*</span> <span class="n">x</span><span class="p">;</span> |
| |
| <span class="c1">-- Replace a SQL table function.</span> |
| <span class="o">></span> <span class="k">CREATE</span> <span class="k">OR</span> <span class="k">REPLACE</span> <span class="k">FUNCTION</span> <span class="n">getemps</span><span class="p">(</span><span class="n">deptno</span> <span class="nb">INT</span><span class="p">)</span> |
| <span class="k">RETURNS</span> <span class="k">TABLE</span> <span class="p">(</span><span class="n">name</span> <span class="n">STRING</span><span class="p">)</span> |
| <span class="k">RETURN</span> <span class="k">SELECT</span> <span class="n">name</span> <span class="k">FROM</span> <span class="n">employee</span> <span class="n">e</span> <span class="k">WHERE</span> <span class="n">e</span><span class="p">.</span><span class="n">deptno</span> <span class="o">=</span> <span class="n">getemps</span><span class="p">.</span><span class="n">deptno</span><span class="p">;</span> |
| |
| <span class="c1">-- Describe a SQL table function.</span> |
| <span class="o">></span> <span class="k">DESCRIBE</span> <span class="k">FUNCTION</span> <span class="n">getemps</span><span class="p">;</span> |
| <span class="k">Function</span><span class="p">:</span> <span class="k">default</span><span class="p">.</span><span class="n">getemps</span> |
| <span class="k">Type</span><span class="p">:</span> <span class="k">TABLE</span> |
| <span class="k">Input</span><span class="p">:</span> <span class="n">deptno</span> <span class="nb">INT</span> |
| <span class="k">Returns</span><span class="p">:</span> <span class="n">id</span> <span class="nb">INT</span> |
| <span class="n">name</span> <span class="n">STRING</span> |
| </code></pre></div></div> |
| |
| <h3 id="describe-a-sql-function">Describe a SQL function</h3> |
| |
| <div class="language-sql highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="o">></span> <span class="k">DESCRIBE</span> <span class="k">FUNCTION</span> <span class="n">hello</span><span class="p">;</span> |
| <span class="k">Function</span><span class="p">:</span> <span class="n">hello</span> |
| <span class="k">Type</span><span class="p">:</span> <span class="n">SCALAR</span> |
| <span class="k">Input</span><span class="p">:</span> <span class="p">()</span> |
| <span class="k">Returns</span><span class="p">:</span> <span class="n">STRING</span> |
| |
| <span class="o">></span> <span class="k">DESCRIBE</span> <span class="k">FUNCTION</span> <span class="n">area</span><span class="p">;</span> |
| <span class="k">Function</span><span class="p">:</span> <span class="k">default</span><span class="p">.</span><span class="n">area</span> |
| <span class="k">Type</span><span class="p">:</span> <span class="n">SCALAR</span> |
| <span class="k">Input</span><span class="p">:</span> <span class="n">x</span> <span class="nb">DOUBLE</span> |
| <span class="n">y</span> <span class="nb">DOUBLE</span> |
| <span class="k">Returns</span><span class="p">:</span> <span class="nb">DOUBLE</span> |
| |
| <span class="o">></span> <span class="k">DESCRIBE</span> <span class="k">FUNCTION</span> <span class="n">roll_dice</span><span class="p">;</span> |
| <span class="k">Function</span><span class="p">:</span> <span class="k">default</span><span class="p">.</span><span class="n">roll_dice</span> |
| <span class="k">Type</span><span class="p">:</span> <span class="n">SCALAR</span> |
| <span class="k">Input</span><span class="p">:</span> <span class="n">num_dice</span> <span class="nb">INT</span> |
| <span class="n">num_sides</span> <span class="nb">INT</span> |
| <span class="k">Returns</span><span class="p">:</span> <span class="nb">INT</span> |
| </code></pre></div></div> |
| |
| <h3 id="related-statements">Related Statements</h3> |
| |
| <ul> |
| <li><a href="sql-ref-syntax-aux-show-functions.html">SHOW FUNCTIONS</a></li> |
| <li><a href="sql-ref-syntax-aux-describe-function.html">DESCRIBE FUNCTION</a></li> |
| <li><a href="sql-ref-syntax-ddl-drop-function.html">DROP FUNCTION</a></li> |
| </ul> |
| |
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