path: root/doc/src/sgml/ref/insert.sgml

<!--
doc/src/sgml/ref/insert.sgml
PostgreSQL documentation
-->

<refentry id="SQL-INSERT">
 <indexterm zone="sql-insert">
  <primary>INSERT</primary>
 </indexterm>

 <refmeta>
  <refentrytitle>INSERT</refentrytitle>
  <manvolnum>7</manvolnum>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>INSERT</refname>
  <refpurpose>create new rows in a table</refpurpose>
 </refnamediv>

 <refsynopsisdiv>
<synopsis>
[ WITH [ RECURSIVE ] <replaceable class="parameter">with_query</replaceable> [, ...] ]
INSERT INTO <replaceable class="PARAMETER">table_name</replaceable> [ AS <replaceable class="parameter">alias</replaceable> ] [ ( <replaceable class="PARAMETER">column_name</replaceable> [, ...] ) ]
    { DEFAULT VALUES | VALUES ( { <replaceable class="PARAMETER">expression</replaceable> | DEFAULT } [, ...] ) [, ...] | <replaceable class="PARAMETER">query</replaceable> }
    [ ON CONFLICT [ <replaceable class="parameter">conflict_target</replaceable> ] <replaceable class="parameter">conflict_action</replaceable> ]
    [ RETURNING * | <replaceable class="parameter">output_expression</replaceable> [ [ AS ] <replaceable class="parameter">output_name</replaceable> ] [, ...] ]

<phrase>where <replaceable class="parameter">conflict_target</replaceable> can be one of:</phrase>

    ( { <replaceable class="parameter">column_name_index</replaceable> | ( <replaceable class="parameter">expression_index</replaceable> ) } [ COLLATE <replaceable class="parameter">collation</replaceable> ] [ <replaceable class="parameter">opclass</replaceable> ] [, ...] ) [ WHERE <replaceable class="PARAMETER">index_predicate</replaceable> ]
    ON CONSTRAINT <replaceable class="PARAMETER">constraint_name</replaceable>

<phrase>and <replaceable class="parameter">conflict_action</replaceable> is one of:</phrase>

    DO NOTHING
    DO UPDATE SET { <replaceable class="PARAMETER">column_name</replaceable> = { <replaceable class="PARAMETER">expression</replaceable> | DEFAULT } |
                    ( <replaceable class="PARAMETER">column_name</replaceable> [, ...] ) = ( { <replaceable class="PARAMETER">expression</replaceable> | DEFAULT } [, ...] ) |
                    ( <replaceable class="PARAMETER">column_name</replaceable> [, ...] ) = ( <replaceable class="PARAMETER">sub-SELECT</replaceable> )
                  } [, ...]
              [ WHERE <replaceable class="PARAMETER">condition</replaceable> ]
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <command>INSERT</command> inserts new rows into a table.
   One can insert one or more rows specified by value expressions,
   or zero or more rows resulting from a query.
  </para>

  <para>
   The target column names can be listed in any order.  If no list of
   column names is given at all, the default is all the columns of the
   table in their declared order; or the first <replaceable>N</> column
   names, if there are only <replaceable>N</> columns supplied by the
   <literal>VALUES</> clause or <replaceable>query</>.  The values
   supplied by the <literal>VALUES</> clause or <replaceable>query</> are
   associated with the explicit or implicit column list left-to-right.
  </para>

  <para>
   Each column not present in the explicit or implicit column list will be
   filled with a default value, either its declared default value
   or null if there is none.
  </para>

  <para>
   If the expression for any column is not of the correct data type,
   automatic type conversion will be attempted.
  </para>

  <para>
   <literal>ON CONFLICT</> can be used to specify an alternative
   action to raising a unique constraint or exclusion constraint
   violation error. (See <xref linkend="sql-on-conflict"
   endterm="sql-on-conflict-title"> below.)
  </para>

  <para>
   The optional <literal>RETURNING</> clause causes <command>INSERT</>
   to compute and return value(s) based on each row actually inserted
   (or updated, if an <literal>ON CONFLICT DO UPDATE</> clause was
   used).  This is primarily useful for obtaining values that were
   supplied by defaults, such as a serial sequence number.  However,
   any expression using the table's columns is allowed.  The syntax of
   the <literal>RETURNING</> list is identical to that of the output
   list of <command>SELECT</>.  Only rows that were successfully
   inserted or updated will be returned.  For example, if a row was
   locked but not updated because an <literal>ON CONFLICT DO UPDATE
   ... WHERE</literal> clause <replaceable
   class="PARAMETER">condition</replaceable> was not satisfied, the
   row will not be returned.
  </para>

  <para>
   You must have <literal>INSERT</literal> privilege on a table in
   order to insert into it.  If <literal>ON CONFLICT DO UPDATE</> is
   present the <literal>UPDATE</literal> privilege is also required.
  </para>

  <para>
   If a column list is specified, you only need
   <literal>INSERT</literal> privilege on the listed columns.
   Similarly, when <literal>ON CONFLICT DO UPDATE</> is specified, you
   only need <literal>UPDATE</> privilege on the column(s) that are
   listed to be updated.  However, <literal>ON CONFLICT DO UPDATE</>
   also requires <literal>SELECT</> privilege on any column whose
   values are read in the <literal>ON CONFLICT DO UPDATE</>
   expressions or <replaceable>condition</>.
  </para>

  <para>
   Use of the <literal>RETURNING</> clause requires <literal>SELECT</>
   privilege on all columns mentioned in <literal>RETURNING</>.
   If you use the <replaceable
   class="PARAMETER">query</replaceable> clause to insert rows from a
   query, you of course need to have <literal>SELECT</literal> privilege on
   any table or column used in the query.
  </para>
 </refsect1>

 <refsect1>
  <title>Parameters</title>

  <variablelist>
   <varlistentry>
    <term><replaceable class="parameter">with_query</replaceable></term>
    <listitem>
     <para>
      The <literal>WITH</literal> clause allows you to specify one or more
      subqueries that can be referenced by name in the <command>INSERT</>
      query. See <xref linkend="queries-with"> and <xref linkend="sql-select">
      for details.
     </para>
     <para>
      It is possible for the <replaceable class="parameter">query</replaceable>
      (<command>SELECT</command> statement)
      to also contain a <literal>WITH</literal> clause.  In such a case both
      sets of <replaceable>with_query</replaceable> can be referenced within
      the <replaceable class="parameter">query</replaceable>, but the
      second one takes precedence since it is more closely nested.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">table_name</replaceable></term>
    <listitem>
     <para>
      The name (optionally schema-qualified) of an existing table.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="parameter">alias</replaceable></term>
    <listitem>
     <para>
      A substitute name for the target table. When an alias is provided, it
      completely hides the actual name of the table.  This is particularly
      useful when using <literal>ON CONFLICT DO UPDATE</literal> into a table
      named <literal>excluded</literal> as that's also the name of the
      pseudo-relation containing the proposed row.
     </para>
    </listitem>
   </varlistentry>


   <varlistentry>
    <term><replaceable class="PARAMETER">column_name</replaceable></term>
    <listitem>
     <para>
      The name of a column in the table named by <replaceable class="PARAMETER">table_name</replaceable>.
      The column name can be qualified with a subfield name or array
      subscript, if needed.  (Inserting into only some fields of a
      composite column leaves the other fields null.)  When
      referencing a column with <literal>ON CONFLICT DO UPDATE</>, do
      not include the table's name in the specification of a target
      column.  For example, <literal>INSERT ... ON CONFLICT DO UPDATE
      tab SET table_name.col = 1</> is invalid (this follows the general
      behavior for <command>UPDATE</>).
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>DEFAULT VALUES</literal></term>
    <listitem>
     <para>
      All columns will be filled with their default values.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">expression</replaceable></term>
    <listitem>
     <para>
      An expression or value to assign to the corresponding column.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>DEFAULT</literal></term>
    <listitem>
     <para>
      The corresponding column will be filled with
      its default value.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">query</replaceable></term>
    <listitem>
     <para>
      A query (<command>SELECT</command> statement) that supplies the
      rows to be inserted.  Refer to the
      <xref linkend="sql-select">
      statement for a description of the syntax.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">output_expression</replaceable></term>
    <listitem>
     <para>
      An expression to be computed and returned by the <command>INSERT</>
      command after each row is inserted (not updated). The
      expression can use any column names of the table named by
      <replaceable class="PARAMETER">table_name</replaceable>.
      Write <literal>*</> to return all columns of the inserted row(s).
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>conflict_target</literal></term>
    <listitem>
     <para>
      Specify which conflicts <literal>ON CONFLICT</literal> refers to.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>conflict_action</literal></term>
    <listitem>
     <para>
      <literal>DO NOTHING</literal> or <literal>DO UPDATE
      SET</literal> clause specifying the action to be performed in
      case of a conflict.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">output_name</replaceable></term>
    <listitem>
     <para>
      A name to use for a returned column.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">column_name_index</replaceable></term>
    <listitem>
     <para>
      The name of a <replaceable
      class="PARAMETER">table_name</replaceable> column.  Part of a
      unique index inference clause.  Follows <command>CREATE
      INDEX</command> format.  <literal>SELECT</> privilege on
      <replaceable class="PARAMETER">column_name_index</replaceable>
      is required.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">expression_index</replaceable></term>
    <listitem>
     <para>
      Similar to <replaceable
      class="PARAMETER">column_name_index</replaceable>, but used to
      infer expressions on <replaceable
      class="PARAMETER">table_name</replaceable> columns appearing
      within index definitions (not simple columns).  Part of unique
      index inference clause.  Follows <command>CREATE INDEX</command>
      format.  <literal>SELECT</> privilege on any column appearing
      within <replaceable
      class="PARAMETER">expression_index</replaceable> is required.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">collation</replaceable></term>
    <listitem>
     <para>
      When specified, mandates that corresponding <replaceable
      class="PARAMETER">column_name_index</replaceable> or
      <replaceable class="PARAMETER">expression_index</replaceable> use a
      particular collation in order to be matched in the inference clause.
      Typically this is omitted, as collations usually do not affect wether or
      not a constraint violation occurs.  Follows <command>CREATE
      INDEX</command> format.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">opclass</replaceable></term>
    <listitem>
     <para>
      When specified, mandates that corresponding <replaceable
      class="PARAMETER">column_name_index</replaceable> or
      <replaceable class="PARAMETER">expression_index</replaceable> use
      particular operator class in order to be matched by the inference
      clause.  Sometimes this is omitted because the
      <emphasis>equality</emphasis> semantics are often equivalent across a
      type's operator classes anyway, or because it's sufficient to trust that
      the defined unique indexes have the pertinent definition of equality.
      Follows <command>CREATE INDEX</command> format.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">index_predicate</replaceable></term>
    <listitem>
     <para>
      Used to allow inference of partial unique indexes.  Any indexes
      that satisfy the predicate (which need not actually be partial
      indexes) can be matched by the rest of the inference clause.
      Follows <command>CREATE INDEX</command> format.
      <literal>SELECT</> privilege on any column appearing within
      <replaceable class="PARAMETER">index_predicate</replaceable> is
      required.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">constraint_name</replaceable></term>
    <listitem>
     <para>
      Explicitly specifies an arbiter <emphasis>constraint</emphasis>
      by name, rather than inferring a constraint or index.  This is
      mostly useful for exclusion constraints, that cannot be chosen
      in the conventional way (with an inference clause).
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">condition</replaceable></term>
    <listitem>
     <para>
      An expression that returns a value of type <type>boolean</type>.  Only
      rows for which this expression returns <literal>true</literal> will be
      updated, although all rows will be locked when the
      <literal>ON CONFLICT DO UPDATE</> action is taken.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1 id="sql-on-conflict">
  <title id="sql-on-conflict-title"><literal>ON CONFLICT</literal> Clause</title>
  <indexterm zone="SQL-INSERT">
   <primary>UPSERT</primary>
  </indexterm>
  <indexterm zone="SQL-INSERT">
   <primary>ON CONFLICT</primary>
  </indexterm>
  <para>
   The optional <literal>ON CONFLICT</literal> clause specifies an
   alternative action to raising a unique violation or exclusion
   constraint violation error.  For each individual row proposed for
   insertion, either the insertion proceeds, or, if a constraint
   specified by the <parameter>conflict_target</parameter> is
   violated, the alternative <parameter>conflict_action</parameter> is
   taken.
  </para>

  <para>
   <parameter>conflict_target</parameter> describes which conflicts
   are handled by the <literal>ON CONFLICT</literal> clause.  Either a
   <emphasis>unique index inference</emphasis> clause or an explicitly
   named constraint can be used.  For <literal>ON CONFLICT DO
   NOTHING</literal>, it is optional to specify a
   <parameter>conflict_target</parameter>; when omitted, conflicts
   with all usable constraints (and unique indexes) are handled.  For
   <literal>ON CONFLICT DO UPDATE</literal>, a conflict target
   <emphasis>must</emphasis> be specified.

   Every time an insertion without <literal>ON CONFLICT</literal>
   would ordinarily raise an error due to violating one of the
   inferred (or explicitly named) constraints, a conflict (as in
   <literal>ON CONFLICT</literal>) occurs, and the alternative action,
   as specified by <parameter>conflict_action</parameter> is taken.
   This happens on a row-by-row basis.
  </para>

  <para>
   A <emphasis>unique index inference</emphasis> clause consists of
   one or more <replaceable
   class="PARAMETER">column_name_index</replaceable> columns and/or
   <replaceable class="PARAMETER">expression_index</replaceable>
   expressions, and a optional <replaceable class="PARAMETER">
   index_predicate</replaceable>.
  </para>

  <para>
   All the <replaceable class="PARAMETER">table_name</replaceable>
   unique indexes that, without regard to order, contain exactly the
   specified columns/expressions and, if specified, whose predicate
   implies the <replaceable class="PARAMETER">
   index_predicate</replaceable> are chosen as arbiter indexes.  Note
   that this means an index without a predicate will be used if a
   non-partial index matching every other criteria happens to be
   available.
  </para>

  <para>
   If no index matches the inference clause (nor is there a constraint
   explicitly named), an error is raised.  Deferred constraints are
   not supported as arbiters.
  </para>

  <para>
   <parameter>conflict_action</parameter> defines the action to be
   taken in case of conflict.  <literal>ON CONFLICT DO
   NOTHING</literal> simply avoids inserting a row as its alternative
   action.  <literal>ON CONFLICT DO UPDATE</literal> updates the
   existing row that conflicts with the row proposed for insertion as
   its alternative action.

   <literal>ON CONFLICT DO UPDATE</literal> guarantees an atomic
   <command>INSERT</command> or <command>UPDATE</command> outcome - provided
   there is no independent error, one of those two outcomes is guaranteed,
   even under high concurrency.  This feature is also known as
   <firstterm>UPSERT</firstterm>.

   Note that exclusion constraints are not supported with
   <literal>ON CONFLICT DO UPDATE</literal>.
  </para>

  <para>
   <literal>ON CONFLICT DO UPDATE</literal> optionally accepts
   a <literal>WHERE</literal> clause <replaceable>condition</replaceable>.
   When provided, the statement only proceeds with updating if
   the <replaceable>condition</replaceable> is satisfied.  Otherwise, unlike a
   conventional <command>UPDATE</command>, the row is still locked for update.
   Note that the <replaceable>condition</replaceable> is evaluated last, after
   a conflict has been identified as a candidate to update.
  </para>

  <para>
   The <literal>SET</literal> and <literal>WHERE</literal> clauses in
   <literal>ON CONFLICT UPDATE</literal> have access to the existing
   row, using the table's name, and to the row
   proposed for insertion, using the <varname>excluded</varname>
   alias.  The <varname>excluded</varname> alias requires
   <literal>SELECT</> privilege on any column whose values are read.

   Note that the effects of all per-row <literal>BEFORE INSERT</literal>
   triggers are reflected in <varname>excluded</varname> values, since those
   effects may have contributed to the row being excluded from insertion.
  </para>

  <para>
   <command>INSERT</command> with an <literal>ON CONFLICT DO UPDATE</>
   clause is a <quote>deterministic</quote> statement.  This means
   that the command will not be allowed to affect any single existing
   row more than once; a cardinality violation error will be raised
   when this situation arises.  Rows proposed for insertion should not
   duplicate each other in terms of attributes constrained by the
   conflict-arbitrating unique index.
  </para>
 </refsect1>

 <refsect1>
  <title>Outputs</title>

  <para>
   On successful completion, an <command>INSERT</> command returns a command
   tag of the form
<screen>
INSERT <replaceable>oid</replaceable> <replaceable class="parameter">count</replaceable>
</screen>
   However, in the event of an <literal>ON CONFLICT DO UPDATE</> clause
   (but <emphasis>not</emphasis> in the event of an <literal>ON
   CONFLICT DO NOTHING</> clause), the command tag reports the number of
   rows inserted or updated together, of the form
<screen>
UPSERT <replaceable>oid</replaceable> <replaceable class="parameter">count</replaceable>
</screen>
   The <replaceable class="parameter">count</replaceable> is the number
   of rows inserted.  If <replaceable class="parameter">count</replaceable>
   is exactly one, and the target table has OIDs, then
   <replaceable class="parameter">oid</replaceable> is the
   <acronym>OID</acronym>
   assigned to the inserted row (but not if there is only a single
   updated row).  Otherwise <replaceable
   class="parameter">oid</replaceable> is zero.
  </para>

  <para>
   If the <command>INSERT</> command contains a <literal>RETURNING</>
   clause, the result will be similar to that of a <command>SELECT</>
   statement containing the columns and values defined in the
   <literal>RETURNING</> list, computed over the row(s) inserted or
   updated by the command.
  </para>
 </refsect1>

 <refsect1>
  <title>Examples</title>

  <para>
   Insert a single row into table <literal>films</literal>:

<programlisting>
INSERT INTO films VALUES
    ('UA502', 'Bananas', 105, '1971-07-13', 'Comedy', '82 minutes');
</programlisting>
  </para>

  <para>
   In this example, the <literal>len</literal> column is
   omitted and therefore it will have the default value:

<programlisting>
INSERT INTO films (code, title, did, date_prod, kind)
    VALUES ('T_601', 'Yojimbo', 106, '1961-06-16', 'Drama');
</programlisting>
  </para>

  <para>
   This example uses the <literal>DEFAULT</literal> clause for
   the date columns rather than specifying a value:

<programlisting>
INSERT INTO films VALUES
    ('UA502', 'Bananas', 105, DEFAULT, 'Comedy', '82 minutes');
INSERT INTO films (code, title, did, date_prod, kind)
    VALUES ('T_601', 'Yojimbo', 106, DEFAULT, 'Drama');
</programlisting>
  </para>

  <para>
   To insert a row consisting entirely of default values:

<programlisting>
INSERT INTO films DEFAULT VALUES;
</programlisting>
  </para>

  <para>
   To insert multiple rows using the multirow <command>VALUES</> syntax:

<programlisting>
INSERT INTO films (code, title, did, date_prod, kind) VALUES
    ('B6717', 'Tampopo', 110, '1985-02-10', 'Comedy'),
    ('HG120', 'The Dinner Game', 140, DEFAULT, 'Comedy');
</programlisting>
  </para>

  <para>
   This example inserts some rows into table
   <literal>films</literal> from a table <literal>tmp_films</literal>
   with the same column layout as <literal>films</literal>:

<programlisting>
INSERT INTO films SELECT * FROM tmp_films WHERE date_prod &lt; '2004-05-07';
</programlisting>
  </para>

  <para>
   This example inserts into array columns:

<programlisting>
-- Create an empty 3x3 gameboard for noughts-and-crosses
INSERT INTO tictactoe (game, board[1:3][1:3])
    VALUES (1, '{{" "," "," "},{" "," "," "},{" "," "," "}}');
-- The subscripts in the above example aren't really needed
INSERT INTO tictactoe (game, board)
    VALUES (2, '{{X," "," "},{" ",O," "},{" ",X," "}}');
</programlisting>
  </para>

  <para>
   Insert a single row into table <literal>distributors</literal>, returning
   the sequence number generated by the <literal>DEFAULT</literal> clause:

<programlisting>
INSERT INTO distributors (did, dname) VALUES (DEFAULT, 'XYZ Widgets')
   RETURNING did;
</programlisting>
  </para>

  <para>
   Increment the sales count of the salesperson who manages the
   account for Acme Corporation, and record the whole updated row
   along with current time in a log table:
<programlisting>
WITH upd AS (
  UPDATE employees SET sales_count = sales_count + 1 WHERE id =
    (SELECT sales_person FROM accounts WHERE name = 'Acme Corporation')
    RETURNING *
)
INSERT INTO employees_log SELECT *, current_timestamp FROM upd;
</programlisting>
  </para>
  <para>
   Insert or update new distributors as appropriate.  Assumes a unique
   index has been defined that constrains values appearing in the
   <literal>did</literal> column.  Note that an <varname>EXCLUDED</>
   expression is used to reference values originally proposed for
   insertion:
<programlisting>
  INSERT INTO distributors (did, dname)
  VALUES (5, 'Gizmo transglobal'), (6, 'Associated Computing, inc')
  ON CONFLICT (did) DO UPDATE SET dname = EXCLUDED.dname;
</programlisting>
  </para>
  <para>
   Insert a distributor, or do nothing for rows proposed for insertion
   when an existing, excluded row (a row with a matching constrained
   column or columns after before row insert triggers fire) exists.
   Example assumes a unique index has been defined that constrains
   values appearing in the <literal>did</literal> column:
<programlisting>
  INSERT INTO distributors (did, dname) VALUES (7, 'Redline GmbH')
  ON CONFLICT (did) DO NOTHING;
</programlisting>
  </para>
  <para>
   Insert or update new distributors as appropriate.  Example assumes
   a unique index has been defined that constrains values appearing in
   the <literal>did</literal> column.  <literal>WHERE</> clause is
   used to limit the rows actually updated (any existing row not
   updated will still be locked, though):
<programlisting>
  -- Don't update existing distributors based in a certain ZIP code
  INSERT INTO distributors AS d (did, dname) VALUES (8, 'Anvil Distribution')
  ON CONFLICT (did) DO UPDATE
  SET dname = EXCLUDED.dname || ' (formerly ' || d.dname || ')'
  WHERE d.zipcode != '21201';

  -- Name a constraint directly in the statement (uses associated
  -- index to arbitrate taking the DO NOTHING action)
  INSERT INTO distributors (did, dname) VALUES (9, 'Antwerp Design')
  ON CONFLICT ON CONSTRAINT distributors_pkey DO NOTHING;
</programlisting>
  </para>
  <para>
   Insert new distributor if possible;  otherwise
   <literal>DO NOTHING</literal>.  Example assumes a unique index has been
   defined that constrains values appearing in the
   <literal>did</literal> column on a subset of rows where the
   <literal>is_active</literal> boolean column evaluates to
   <literal>true</literal>:
<programlisting>
  -- This statement could infer a partial unique index on "did"
  -- with a predicate of "WHERE is_active", but it could also
  -- just use a regular unique constraint on "did"
  INSERT INTO distributors (did, dname) VALUES (10, 'Conrad International')
  ON CONFLICT (did) WHERE is_active DO NOTHING;
</programlisting>
  </para>
 </refsect1>

 <refsect1>
  <title>Compatibility</title>

  <para>
   <command>INSERT</command> conforms to the SQL standard, except that
   the <literal>RETURNING</> clause is a
   <productname>PostgreSQL</productname> extension, as is the ability
   to use <literal>WITH</> with <command>INSERT</>, and the ability to
   specify an alternative action with <literal>ON CONFLICT</>.
   Also, the case in
   which a column name list is omitted, but not all the columns are
   filled from the <literal>VALUES</> clause or <replaceable>query</>,
   is disallowed by the standard.
  </para>

  <para>
   Possible limitations of the <replaceable
   class="PARAMETER">query</replaceable> clause are documented under
   <xref linkend="sql-select">.
  </para>
 </refsect1>
</refentry>