<!--
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> [, ...] ) ]
[ OVERRIDING { SYSTEM | USER } VALUE ]
{ 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 [ WITH ( { OLD | NEW } AS <replaceable class="parameter">output_alias</replaceable> [, ...] ) ]
{ * | <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">index_column_name</replaceable> | ( <replaceable class="parameter">index_expression</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> [, ...] ) = [ ROW ] ( { <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</replaceable> column
names, if there are only <replaceable>N</replaceable> columns supplied by the
<literal>VALUES</literal> clause or <replaceable>query</replaceable>. The values
supplied by the <literal>VALUES</literal> clause or <replaceable>query</replaceable> 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>
<command>INSERT</command> into tables that lack unique indexes will
not be blocked by concurrent activity. Tables with unique indexes
might block if concurrent sessions perform actions that lock or modify
rows matching the unique index values being inserted; the details
are covered in <xref linkend="index-unique-checks"/>.
<literal>ON CONFLICT</literal> can be used to specify an alternative
action to raising a unique constraint or exclusion constraint
violation error. (See <xref linkend="sql-on-conflict"/> below.)
</para>
<para>
The optional <literal>RETURNING</literal> clause causes <command>INSERT</command>
to compute and return value(s) based on each row actually inserted
(or updated, if an <literal>ON CONFLICT DO UPDATE</literal> 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</literal> list is identical to that of the output
list of <command>SELECT</command>. 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</literal> is
present, <literal>UPDATE</literal> privilege on the table 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</literal> is specified, you
only need <literal>UPDATE</literal> privilege on the column(s) that are
listed to be updated. However, <literal>ON CONFLICT DO UPDATE</literal>
also requires <literal>SELECT</literal> privilege on any column whose
values are read in the <literal>ON CONFLICT DO UPDATE</literal>
expressions or <replaceable>condition</replaceable>.
</para>
<para>
Use of the <literal>RETURNING</literal> clause requires <literal>SELECT</literal>
privilege on all columns mentioned in <literal>RETURNING</literal>.
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>
<refsect2>
<title>Inserting</title>
<para>
This section covers parameters that may be used when only
inserting new rows. Parameters <emphasis>exclusively</emphasis>
used with the <literal>ON CONFLICT</literal> clause are described
separately.
</para>
<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</command>
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 <replaceable
class="parameter">table_name</replaceable>. When an alias is
provided, it completely hides the actual name of the table.
This is particularly useful when <literal>ON CONFLICT DO UPDATE</literal>
targets a table named <varname>excluded</varname>, since that will otherwise
be taken as the name of the special table representing the row proposed
for insertion.
</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</literal>, do not include
the table's name in the specification of a target column. For
example, <literal>INSERT INTO table_name ... ON CONFLICT DO UPDATE
SET table_name.col = 1</literal> is invalid (this follows the general
behavior for <command>UPDATE</command>).
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>OVERRIDING SYSTEM VALUE</literal></term>
<listitem>
<para>
If this clause is specified, then any values supplied for identity
columns will override the default sequence-generated values.
</para>
<para>
For an identity column defined as <literal>GENERATED ALWAYS</literal>,
it is an error to insert an explicit value (other than
<literal>DEFAULT</literal>) without specifying either
<literal>OVERRIDING SYSTEM VALUE</literal> or <literal>OVERRIDING USER
VALUE</literal>. (For an identity column defined as
<literal>GENERATED BY DEFAULT</literal>, <literal>OVERRIDING SYSTEM
VALUE</literal> is the normal behavior and specifying it does nothing,
but <productname>PostgreSQL</productname> allows it as an extension.)
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>OVERRIDING USER VALUE</literal></term>
<listitem>
<para>
If this clause is specified, then any values supplied for identity
columns are ignored and the default sequence-generated values are
applied.
</para>
<para>
This clause is useful for example when copying values between tables.
Writing <literal>INSERT INTO tbl2 OVERRIDING USER VALUE SELECT * FROM
tbl1</literal> will copy from <literal>tbl1</literal> all columns that
are not identity columns in <literal>tbl2</literal> while values for
the identity columns in <literal>tbl2</literal> will be generated by
the sequences associated with <literal>tbl2</literal>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>DEFAULT VALUES</literal></term>
<listitem>
<para>
All columns will be filled with their default values, as if
<literal>DEFAULT</literal> were explicitly specified for each column.
(An <literal>OVERRIDING</literal> clause is not permitted in this
form.)
</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. An
identity column will be filled with a new value generated by the
associated sequence. For a generated column, specifying this is
permitted but merely specifies the normal behavior of computing the
column from its generation expression.
</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_alias</replaceable></term>
<listitem>
<para>
An optional substitute name for <literal>OLD</literal> or
<literal>NEW</literal> rows in the <literal>RETURNING</literal> list.
</para>
<para>
By default, old values from the target table can be returned by writing
<literal>OLD.<replaceable class="parameter">column_name</replaceable></literal>
or <literal>OLD.*</literal>, and new values can be returned by writing
<literal>NEW.<replaceable class="parameter">column_name</replaceable></literal>
or <literal>NEW.*</literal>. When an alias is provided, these names are
hidden and the old or new rows must be referred to using the alias.
For example <literal>RETURNING WITH (OLD AS o, NEW AS n) o.*, n.*</literal>.
</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> command after each row is inserted or
updated. The expression can use any column names of the table
named by <replaceable
class="parameter">table_name</replaceable>. Write
<literal>*</literal> to return all columns of the inserted or updated
row(s).
</para>
<para>
A column name or <literal>*</literal> may be qualified using
<literal>OLD</literal> or <literal>NEW</literal>, or the corresponding
<replaceable class="parameter">output_alias</replaceable> for
<literal>OLD</literal> or <literal>NEW</literal>, to cause old or new
values to be returned. An unqualified column name, or
<literal>*</literal>, or a column name or <literal>*</literal>
qualified using the target table name or alias will return new values.
</para>
<para>
For a simple <command>INSERT</command>, all old values will be
<literal>NULL</literal>. However, for an <command>INSERT</command>
with an <literal>ON CONFLICT DO UPDATE</literal> clause, the old
values may be non-<literal>NULL</literal>.
</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>
</variablelist>
</refsect2>
<refsect2 id="sql-on-conflict" xreflabel="ON CONFLICT Clause">
<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 an
<emphasis>arbiter</emphasis> constraint or index specified by
<parameter>conflict_target</parameter> is violated, the
alternative <parameter>conflict_action</parameter> is taken.
<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.
</para>
<para>
<parameter>conflict_target</parameter> can perform
<emphasis>unique index inference</emphasis>. When performing
inference, it consists of one or more <replaceable
class="parameter">index_column_name</replaceable> columns and/or
<replaceable class="parameter">index_expression</replaceable>
expressions, and an optional <replaceable class="parameter">index_predicate</replaceable>. All <replaceable
class="parameter">table_name</replaceable> unique indexes that,
without regard to order, contain exactly the
<parameter>conflict_target</parameter>-specified
columns/expressions are inferred (chosen) as arbiter indexes. If
an <replaceable class="parameter">index_predicate</replaceable> is
specified, it must, as a further requirement for inference,
satisfy arbiter indexes. Note that this means a non-partial
unique index (a unique index without a predicate) will be inferred
(and thus used by <literal>ON CONFLICT</literal>) if such an index
satisfying every other criteria is available. If an attempt at
inference is unsuccessful, an error is raised.
</para>
<para>
<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 is also known as
<firstterm>UPSERT</firstterm> &mdash; <quote>UPDATE or
INSERT</quote>.
</para>
<variablelist>
<varlistentry>
<term><replaceable class="parameter">conflict_target</replaceable></term>
<listitem>
<para>
Specifies which conflicts <literal>ON CONFLICT</literal> takes
the alternative action on by choosing <firstterm>arbiter
indexes</firstterm>. Either performs <emphasis>unique index
inference</emphasis>, or names a constraint explicitly. 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 <parameter>conflict_target</parameter>
<emphasis>must</emphasis> be provided.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><replaceable class="parameter">conflict_action</replaceable></term>
<listitem>
<para>
<parameter>conflict_action</parameter> specifies an
alternative <literal>ON CONFLICT</literal> action. It can be
either <literal>DO NOTHING</literal>, or a <literal>DO
UPDATE</literal> clause specifying the exact details of the
<literal>UPDATE</literal> action to be performed in case of a
conflict. The <literal>SET</literal> and
<literal>WHERE</literal> clauses in <literal>ON CONFLICT DO
UPDATE</literal> have access to the existing row using the
table's name (or an alias), and to the row proposed for insertion
using the special <varname>excluded</varname> table.
<literal>SELECT</literal> privilege is required on any column in the
target table where corresponding <varname>excluded</varname>
columns are read.
</para>
<para>
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>
</listitem>
</varlistentry>
<varlistentry>
<term><replaceable class="parameter">index_column_name</replaceable></term>
<listitem>
<para>
The name of a <replaceable
class="parameter">table_name</replaceable> column. Used to
infer arbiter indexes. Follows <command>CREATE
INDEX</command> format. <literal>SELECT</literal> privilege on
<replaceable class="parameter">index_column_name</replaceable>
is required.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><replaceable class="parameter">index_expression</replaceable></term>
<listitem>
<para>
Similar to <replaceable
class="parameter">index_column_name</replaceable>, but used to
infer expressions on <replaceable
class="parameter">table_name</replaceable> columns appearing
within index definitions (not simple columns). Follows
<command>CREATE INDEX</command> format. <literal>SELECT</literal>
privilege on any column appearing within <replaceable
class="parameter">index_expression</replaceable> is required.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><replaceable class="parameter">collation</replaceable></term>
<listitem>
<para>
When specified, mandates that corresponding <replaceable
class="parameter">index_column_name</replaceable> or
<replaceable class="parameter">index_expression</replaceable>
use a particular collation in order to be matched during
inference. Typically this is omitted, as collations usually
do not affect whether 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">index_column_name</replaceable> or
<replaceable class="parameter">index_expression</replaceable>
use particular operator class in order to be matched during
inference. Typically this is omitted, as 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 inferred. Follows <command>CREATE
INDEX</command> format. <literal>SELECT</literal> 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.
</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</literal>
action is taken. Note that
<replaceable>condition</replaceable> is evaluated last, after
a conflict has been identified as a candidate to update.
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
Note that exclusion constraints are not supported as arbiters with
<literal>ON CONFLICT DO UPDATE</literal>. In all cases, only
<literal>NOT DEFERRABLE</literal> constraints and unique indexes
are supported as arbiters.
</para>
<para>
<command>INSERT</command> with an <literal>ON CONFLICT DO UPDATE</literal>
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 an
arbiter index or constraint.
</para>
<para>
Note that it is currently not supported for the
<literal>ON CONFLICT DO UPDATE</literal> clause of an
<command>INSERT</command> applied to a partitioned table to update the
partition key of a conflicting row such that it requires the row be moved
to a new partition.
</para>
<tip>
<para>
It is often preferable to use unique index inference rather than
naming a constraint directly using <literal>ON CONFLICT ON
CONSTRAINT</literal> <replaceable class="parameter">
constraint_name</replaceable>. Inference will continue to work
correctly when the underlying index is replaced by another more
or less equivalent index in an overlapping way, for example when
using <literal>CREATE UNIQUE INDEX ... CONCURRENTLY</literal>
before dropping the index being replaced.
</para>
</tip>
</refsect2>
</refsect1>
<refsect1>
<title>Outputs</title>
<para>
On successful completion, an <command>INSERT</command> command returns a command
tag of the form
<screen>
INSERT <replaceable>oid</replaceable> <replaceable class="parameter">count</replaceable>
</screen>
The <replaceable class="parameter">count</replaceable> is the number of
rows inserted or updated. <replaceable>oid</replaceable> is always 0 (it
used to be the <acronym>OID</acronym> assigned to the inserted row if
<replaceable>count</replaceable> was exactly one and the target table was
declared <literal>WITH OIDS</literal> and 0 otherwise, but creating a table
<literal>WITH OIDS</literal> is not supported anymore).
</para>
<para>
If the <command>INSERT</command> command contains a <literal>RETURNING</literal>
clause, the result will be similar to that of a <command>SELECT</command>
statement containing the columns and values defined in the
<literal>RETURNING</literal> list, computed over the row(s) inserted or
updated by the command.
</para>
</refsect1>
<refsect1>
<title>Notes</title>
<para>
If the specified table is a partitioned table, each row is routed to
the appropriate partition and inserted into it. If the specified table
is a partition, an error will occur if one of the input rows violates
the partition constraint.
</para>
<para>
You may also wish to consider using <command>MERGE</command>, since that
allows mixing <command>INSERT</command>, <command>UPDATE</command>, and
<command>DELETE</command> within a single statement.
See <xref linkend="sql-merge"/>.
</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</command> 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 the special
<varname>excluded</varname> table 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 or update new distributors as above, returning information
about any existing values that were updated, together with the new data
inserted. Note that the returned values for <literal>old_did</literal>
and <literal>old_dname</literal> will be <literal>NULL</literal> for
non-conflicting rows:
<programlisting>
INSERT INTO distributors (did, dname)
VALUES (5, 'Gizmo Transglobal'), (6, 'Associated Computing, Inc')
ON CONFLICT (did) DO UPDATE SET dname = EXCLUDED.dname
RETURNING old.did AS old_did, old.dname AS old_dname,
new.did AS new_did, new.dname AS new_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</literal> 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 &lt;&gt; '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</literal> clause is a
<productname>PostgreSQL</productname> extension, as is the ability
to use <literal>WITH</literal> with <command>INSERT</command>, and the ability to
specify an alternative action with <literal>ON CONFLICT</literal>.
Also, the case in
which a column name list is omitted, but not all the columns are
filled from the <literal>VALUES</literal> clause or <replaceable>query</replaceable>,
is disallowed by the standard. If you prefer a more SQL standard
conforming statement than <literal>ON CONFLICT</literal>, see
<xref linkend="sql-merge"/>.
</para>
<para>
The SQL standard specifies that <literal>OVERRIDING SYSTEM VALUE</literal>
can only be specified if an identity column that is generated always
exists. PostgreSQL allows the clause in any case and ignores it if it is
not applicable.
</para>
<para>
Possible limitations of the <replaceable
class="parameter">query</replaceable> clause are documented under
<xref linkend="sql-select"/>.
</para>
</refsect1>
</refentry>