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diff --git a/doc/src/sgml/html/sql-alterdomain.html b/doc/src/sgml/html/sql-alterdomain.html new file mode 100644 index 0000000..c2d295f --- /dev/null +++ b/doc/src/sgml/html/sql-alterdomain.html @@ -0,0 +1,152 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>ALTER DOMAIN</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="sql-alterdefaultprivileges.html" title="ALTER DEFAULT PRIVILEGES" /><link rel="next" href="sql-altereventtrigger.html" title="ALTER EVENT TRIGGER" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">ALTER DOMAIN</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="sql-alterdefaultprivileges.html" title="ALTER DEFAULT PRIVILEGES">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="sql-commands.html" title="SQL Commands">Up</a></td><th width="60%" align="center">SQL Commands</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 16.2 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="sql-altereventtrigger.html" title="ALTER EVENT TRIGGER">Next</a></td></tr></table><hr /></div><div class="refentry" id="SQL-ALTERDOMAIN"><div class="titlepage"></div><a id="id-1.9.3.9.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle">ALTER DOMAIN</span></h2><p>ALTER DOMAIN — + change the definition of a domain + </p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis"> +ALTER DOMAIN <em class="replaceable"><code>name</code></em> + { SET DEFAULT <em class="replaceable"><code>expression</code></em> | DROP DEFAULT } +ALTER DOMAIN <em class="replaceable"><code>name</code></em> + { SET | DROP } NOT NULL +ALTER DOMAIN <em class="replaceable"><code>name</code></em> + ADD <em class="replaceable"><code>domain_constraint</code></em> [ NOT VALID ] +ALTER DOMAIN <em class="replaceable"><code>name</code></em> + DROP CONSTRAINT [ IF EXISTS ] <em class="replaceable"><code>constraint_name</code></em> [ RESTRICT | CASCADE ] +ALTER DOMAIN <em class="replaceable"><code>name</code></em> + RENAME CONSTRAINT <em class="replaceable"><code>constraint_name</code></em> TO <em class="replaceable"><code>new_constraint_name</code></em> +ALTER DOMAIN <em class="replaceable"><code>name</code></em> + VALIDATE CONSTRAINT <em class="replaceable"><code>constraint_name</code></em> +ALTER DOMAIN <em class="replaceable"><code>name</code></em> + OWNER TO { <em class="replaceable"><code>new_owner</code></em> | CURRENT_ROLE | CURRENT_USER | SESSION_USER } +ALTER DOMAIN <em class="replaceable"><code>name</code></em> + RENAME TO <em class="replaceable"><code>new_name</code></em> +ALTER DOMAIN <em class="replaceable"><code>name</code></em> + SET SCHEMA <em class="replaceable"><code>new_schema</code></em> +</pre></div><div class="refsect1" id="id-1.9.3.9.5"><h2>Description</h2><p> + <code class="command">ALTER DOMAIN</code> changes the definition of an existing domain. + There are several sub-forms: + </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">SET</code>/<code class="literal">DROP DEFAULT</code></span></dt><dd><p> + These forms set or remove the default value for a domain. Note + that defaults only apply to subsequent <code class="command">INSERT</code> + commands; they do not affect rows already in a table using the domain. + </p></dd><dt><span class="term"><code class="literal">SET</code>/<code class="literal">DROP NOT NULL</code></span></dt><dd><p> + These forms change whether a domain is marked to allow NULL + values or to reject NULL values. You can only <code class="literal">SET NOT NULL</code> + when the columns using the domain contain no null values. + </p></dd><dt><span class="term"><code class="literal">ADD <em class="replaceable"><code>domain_constraint</code></em> [ NOT VALID ]</code></span></dt><dd><p> + This form adds a new constraint to a domain using the same syntax as + <a class="link" href="sql-createdomain.html" title="CREATE DOMAIN"><code class="command">CREATE DOMAIN</code></a>. + When a new constraint is added to a domain, all columns using that + domain will be checked against the newly added constraint. These + checks can be suppressed by adding the new constraint using the + <code class="literal">NOT VALID</code> option; the constraint can later be made + valid using <code class="command">ALTER DOMAIN ... VALIDATE CONSTRAINT</code>. + Newly inserted or updated rows are always checked against all + constraints, even those marked <code class="literal">NOT VALID</code>. + <code class="literal">NOT VALID</code> is only accepted for <code class="literal">CHECK</code> constraints. + </p></dd><dt><span class="term"><code class="literal">DROP CONSTRAINT [ IF EXISTS ]</code></span></dt><dd><p> + This form drops constraints on a domain. + If <code class="literal">IF EXISTS</code> is specified and the constraint + does not exist, no error is thrown. In this case a notice is issued instead. + </p></dd><dt><span class="term"><code class="literal">RENAME CONSTRAINT</code></span></dt><dd><p> + This form changes the name of a constraint on a domain. + </p></dd><dt><span class="term"><code class="literal">VALIDATE CONSTRAINT</code></span></dt><dd><p> + This form validates a constraint previously added as + <code class="literal">NOT VALID</code>, that is, it verifies that all values in + table columns of the domain type satisfy the specified constraint. + </p></dd><dt><span class="term"><code class="literal">OWNER</code></span></dt><dd><p> + This form changes the owner of the domain to the specified user. + </p></dd><dt><span class="term"><code class="literal">RENAME</code></span></dt><dd><p> + This form changes the name of the domain. + </p></dd><dt><span class="term"><code class="literal">SET SCHEMA</code></span></dt><dd><p> + This form changes the schema of the domain. Any constraints + associated with the domain are moved into the new schema as well. + </p></dd></dl></div><p> + You must own the domain to use <code class="command">ALTER DOMAIN</code>. + To change the schema of a domain, you must also have + <code class="literal">CREATE</code> privilege on the new schema. + To alter the owner, you must be able to <code class="literal">SET ROLE</code> to the + new owning role, and that role must have <code class="literal">CREATE</code> privilege + on the domain's schema. (These restrictions enforce that altering the owner + doesn't do anything you couldn't do by dropping and recreating the domain. + However, a superuser can alter ownership of any domain anyway.) + </p></div><div class="refsect1" id="id-1.9.3.9.6"><h2>Parameters</h2><p> + </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="replaceable"><code>name</code></em></span></dt><dd><p> + The name (possibly schema-qualified) of an existing domain to + alter. + </p></dd><dt><span class="term"><em class="replaceable"><code>domain_constraint</code></em></span></dt><dd><p> + New domain constraint for the domain. + </p></dd><dt><span class="term"><em class="replaceable"><code>constraint_name</code></em></span></dt><dd><p> + Name of an existing constraint to drop or rename. + </p></dd><dt><span class="term"><code class="literal">NOT VALID</code></span></dt><dd><p> + Do not verify existing stored data for constraint validity. + </p></dd><dt><span class="term"><code class="literal">CASCADE</code></span></dt><dd><p> + Automatically drop objects that depend on the constraint, + and in turn all objects that depend on those objects + (see <a class="xref" href="ddl-depend.html" title="5.14. Dependency Tracking">Section 5.14</a>). + </p></dd><dt><span class="term"><code class="literal">RESTRICT</code></span></dt><dd><p> + Refuse to drop the constraint if there are any dependent + objects. This is the default behavior. + </p></dd><dt><span class="term"><em class="replaceable"><code>new_name</code></em></span></dt><dd><p> + The new name for the domain. + </p></dd><dt><span class="term"><em class="replaceable"><code>new_constraint_name</code></em></span></dt><dd><p> + The new name for the constraint. + </p></dd><dt><span class="term"><em class="replaceable"><code>new_owner</code></em></span></dt><dd><p> + The user name of the new owner of the domain. + </p></dd><dt><span class="term"><em class="replaceable"><code>new_schema</code></em></span></dt><dd><p> + The new schema for the domain. + </p></dd></dl></div><p> + </p></div><div class="refsect1" id="id-1.9.3.9.7"><h2>Notes</h2><p> + Although <code class="command">ALTER DOMAIN ADD CONSTRAINT</code> attempts to verify + that existing stored data satisfies the new constraint, this check is not + bulletproof, because the command cannot <span class="quote">“<span class="quote">see</span>”</span> table rows that + are newly inserted or updated and not yet committed. If there is a hazard + that concurrent operations might insert bad data, the way to proceed is to + add the constraint using the <code class="literal">NOT VALID</code> option, commit + that command, wait until all transactions started before that commit have + finished, and then issue <code class="command">ALTER DOMAIN VALIDATE + CONSTRAINT</code> to search for data violating the constraint. This + method is reliable because once the constraint is committed, all new + transactions are guaranteed to enforce it against new values of the domain + type. + </p><p> + Currently, <code class="command">ALTER DOMAIN ADD CONSTRAINT</code>, <code class="command">ALTER + DOMAIN VALIDATE CONSTRAINT</code>, and <code class="command">ALTER DOMAIN SET NOT + NULL</code> will fail if the named domain or any derived domain is used + within a container-type column (a composite, array, or range column) in + any table in the database. They should eventually be improved to be able + to verify the new constraint for such nested values. + </p></div><div class="refsect1" id="id-1.9.3.9.8"><h2>Examples</h2><p> + To add a <code class="literal">NOT NULL</code> constraint to a domain: +</p><pre class="programlisting"> +ALTER DOMAIN zipcode SET NOT NULL; +</pre><p> + To remove a <code class="literal">NOT NULL</code> constraint from a domain: +</p><pre class="programlisting"> +ALTER DOMAIN zipcode DROP NOT NULL; +</pre><p> + </p><p> + To add a check constraint to a domain: +</p><pre class="programlisting"> +ALTER DOMAIN zipcode ADD CONSTRAINT zipchk CHECK (char_length(VALUE) = 5); +</pre><p> + </p><p> + To remove a check constraint from a domain: +</p><pre class="programlisting"> +ALTER DOMAIN zipcode DROP CONSTRAINT zipchk; +</pre><p> + </p><p> + To rename a check constraint on a domain: +</p><pre class="programlisting"> +ALTER DOMAIN zipcode RENAME CONSTRAINT zipchk TO zip_check; +</pre><p> + </p><p> + To move the domain into a different schema: +</p><pre class="programlisting"> +ALTER DOMAIN zipcode SET SCHEMA customers; +</pre></div><div class="refsect1" id="SQL-ALTERDOMAIN-COMPATIBILITY"><h2>Compatibility</h2><p> + <code class="command">ALTER DOMAIN</code> conforms to the <acronym class="acronym">SQL</acronym> + standard, except for the <code class="literal">OWNER</code>, <code class="literal">RENAME</code>, <code class="literal">SET SCHEMA</code>, and + <code class="literal">VALIDATE CONSTRAINT</code> variants, which are + <span class="productname">PostgreSQL</span> extensions. The <code class="literal">NOT VALID</code> + clause of the <code class="literal">ADD CONSTRAINT</code> variant is also a + <span class="productname">PostgreSQL</span> extension. + </p></div><div class="refsect1" id="SQL-ALTERDOMAIN-SEE-ALSO"><h2>See Also</h2><span class="simplelist"><a class="xref" href="sql-createdomain.html" title="CREATE DOMAIN"><span class="refentrytitle">CREATE DOMAIN</span></a>, <a class="xref" href="sql-dropdomain.html" title="DROP DOMAIN"><span class="refentrytitle">DROP DOMAIN</span></a></span></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="sql-alterdefaultprivileges.html" title="ALTER DEFAULT PRIVILEGES">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="sql-commands.html" title="SQL Commands">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="sql-altereventtrigger.html" title="ALTER EVENT TRIGGER">Next</a></td></tr><tr><td width="40%" align="left" valign="top">ALTER DEFAULT PRIVILEGES </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 16.2 Documentation">Home</a></td><td width="40%" align="right" valign="top"> ALTER EVENT TRIGGER</td></tr></table></div></body></html>
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