'\" t
.\"     Title: INSERT
.\"    Author: The PostgreSQL Global Development Group
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 2024
.\"    Manual: PostgreSQL 16.3 Documentation
.\"    Source: PostgreSQL 16.3
.\"  Language: English
.\"
.TH "INSERT" "7" "2024" "PostgreSQL 16.3" "PostgreSQL 16.3 Documentation"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
INSERT \- create new rows in a table
.SH "SYNOPSIS"
.sp
.nf
[ WITH [ RECURSIVE ] \fIwith_query\fR [, \&.\&.\&.] ]
INSERT INTO \fItable_name\fR [ AS \fIalias\fR ] [ ( \fIcolumn_name\fR [, \&.\&.\&.] ) ]
    [ OVERRIDING { SYSTEM | USER } VALUE ]
    { DEFAULT VALUES | VALUES ( { \fIexpression\fR | DEFAULT } [, \&.\&.\&.] ) [, \&.\&.\&.] | \fIquery\fR }
    [ ON CONFLICT [ \fIconflict_target\fR ] \fIconflict_action\fR ]
    [ RETURNING * | \fIoutput_expression\fR [ [ AS ] \fIoutput_name\fR ] [, \&.\&.\&.] ]

where \fIconflict_target\fR can be one of:

    ( { \fIindex_column_name\fR | ( \fIindex_expression\fR ) } [ COLLATE \fIcollation\fR ] [ \fIopclass\fR ] [, \&.\&.\&.] ) [ WHERE \fIindex_predicate\fR ]
    ON CONSTRAINT \fIconstraint_name\fR

and \fIconflict_action\fR is one of:

    DO NOTHING
    DO UPDATE SET { \fIcolumn_name\fR = { \fIexpression\fR | DEFAULT } |
                    ( \fIcolumn_name\fR [, \&.\&.\&.] ) = [ ROW ] ( { \fIexpression\fR | DEFAULT } [, \&.\&.\&.] ) |
                    ( \fIcolumn_name\fR [, \&.\&.\&.] ) = ( \fIsub\-SELECT\fR )
                  } [, \&.\&.\&.]
              [ WHERE \fIcondition\fR ]
.fi
.SH "DESCRIPTION"
.PP
\fBINSERT\fR
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\&.
.PP
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
\fIN\fR
column names, if there are only
\fIN\fR
columns supplied by the
VALUES
clause or
\fIquery\fR\&. The values supplied by the
VALUES
clause or
\fIquery\fR
are associated with the explicit or implicit column list left\-to\-right\&.
.PP
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\&.
.PP
If the expression for any column is not of the correct data type, automatic type conversion will be attempted\&.
.PP
\fBINSERT\fR
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
Section\ \&64.5\&.
ON CONFLICT
can be used to specify an alternative action to raising a unique constraint or exclusion constraint violation error\&. (See
ON CONFLICT Clause
below\&.)
.PP
The optional
RETURNING
clause causes
\fBINSERT\fR
to compute and return value(s) based on each row actually inserted (or updated, if an
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\*(Aqs columns is allowed\&. The syntax of the
RETURNING
list is identical to that of the output list of
\fBSELECT\fR\&. Only rows that were successfully inserted or updated will be returned\&. For example, if a row was locked but not updated because an
ON CONFLICT DO UPDATE \&.\&.\&. WHERE
clause
\fIcondition\fR
was not satisfied, the row will not be returned\&.
.PP
You must have
INSERT
privilege on a table in order to insert into it\&. If
ON CONFLICT DO UPDATE
is present,
UPDATE
privilege on the table is also required\&.
.PP
If a column list is specified, you only need
INSERT
privilege on the listed columns\&. Similarly, when
ON CONFLICT DO UPDATE
is specified, you only need
UPDATE
privilege on the column(s) that are listed to be updated\&. However,
ON CONFLICT DO UPDATE
also requires
SELECT
privilege on any column whose values are read in the
ON CONFLICT DO UPDATE
expressions or
\fIcondition\fR\&.
.PP
Use of the
RETURNING
clause requires
SELECT
privilege on all columns mentioned in
RETURNING\&. If you use the
\fIquery\fR
clause to insert rows from a query, you of course need to have
SELECT
privilege on any table or column used in the query\&.
.SH "PARAMETERS"
.SS "Inserting"
.PP
This section covers parameters that may be used when only inserting new rows\&. Parameters
\fIexclusively\fR
used with the
ON CONFLICT
clause are described separately\&.
.PP
\fIwith_query\fR
.RS 4
The
WITH
clause allows you to specify one or more subqueries that can be referenced by name in the
\fBINSERT\fR
query\&. See
Section\ \&7.8
and
\fBSELECT\fR(7)
for details\&.
.sp
It is possible for the
\fIquery\fR
(\fBSELECT\fR
statement) to also contain a
WITH
clause\&. In such a case both sets of
\fIwith_query\fR
can be referenced within the
\fIquery\fR, but the second one takes precedence since it is more closely nested\&.
.RE
.PP
\fItable_name\fR
.RS 4
The name (optionally schema\-qualified) of an existing table\&.
.RE
.PP
\fIalias\fR
.RS 4
A substitute name for
\fItable_name\fR\&. When an alias is provided, it completely hides the actual name of the table\&. This is particularly useful when
ON CONFLICT DO UPDATE
targets a table named
\fIexcluded\fR, since that will otherwise be taken as the name of the special table representing the row proposed for insertion\&.
.RE
.PP
\fIcolumn_name\fR
.RS 4
The name of a column in the table named by
\fItable_name\fR\&. 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
ON CONFLICT DO UPDATE, do not include the table\*(Aqs name in the specification of a target column\&. For example,
INSERT INTO table_name \&.\&.\&. ON CONFLICT DO UPDATE SET table_name\&.col = 1
is invalid (this follows the general behavior for
\fBUPDATE\fR)\&.
.RE
.PP
OVERRIDING SYSTEM VALUE
.RS 4
If this clause is specified, then any values supplied for identity columns will override the default sequence\-generated values\&.
.sp
For an identity column defined as
GENERATED ALWAYS, it is an error to insert an explicit value (other than
DEFAULT) without specifying either
OVERRIDING SYSTEM VALUE
or
OVERRIDING USER VALUE\&. (For an identity column defined as
GENERATED BY DEFAULT,
OVERRIDING SYSTEM VALUE
is the normal behavior and specifying it does nothing, but
PostgreSQL
allows it as an extension\&.)
.RE
.PP
OVERRIDING USER VALUE
.RS 4
If this clause is specified, then any values supplied for identity columns are ignored and the default sequence\-generated values are applied\&.
.sp
This clause is useful for example when copying values between tables\&. Writing
INSERT INTO tbl2 OVERRIDING USER VALUE SELECT * FROM tbl1
will copy from
tbl1
all columns that are not identity columns in
tbl2
while values for the identity columns in
tbl2
will be generated by the sequences associated with
tbl2\&.
.RE
.PP
DEFAULT VALUES
.RS 4
All columns will be filled with their default values, as if
DEFAULT
were explicitly specified for each column\&. (An
OVERRIDING
clause is not permitted in this form\&.)
.RE
.PP
\fIexpression\fR
.RS 4
An expression or value to assign to the corresponding column\&.
.RE
.PP
DEFAULT
.RS 4
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\&.
.RE
.PP
\fIquery\fR
.RS 4
A query (\fBSELECT\fR
statement) that supplies the rows to be inserted\&. Refer to the
\fBSELECT\fR(7)
statement for a description of the syntax\&.
.RE
.PP
\fIoutput_expression\fR
.RS 4
An expression to be computed and returned by the
\fBINSERT\fR
command after each row is inserted or updated\&. The expression can use any column names of the table named by
\fItable_name\fR\&. Write
*
to return all columns of the inserted or updated row(s)\&.
.RE
.PP
\fIoutput_name\fR
.RS 4
A name to use for a returned column\&.
.RE
.SS "ON CONFLICT Clause"
.PP
The optional
ON CONFLICT
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
\fIarbiter\fR
constraint or index specified by
\fIconflict_target\fR
is violated, the alternative
\fIconflict_action\fR
is taken\&.
ON CONFLICT DO NOTHING
simply avoids inserting a row as its alternative action\&.
ON CONFLICT DO UPDATE
updates the existing row that conflicts with the row proposed for insertion as its alternative action\&.
.PP
\fIconflict_target\fR
can perform
\fIunique index inference\fR\&. When performing inference, it consists of one or more
\fIindex_column_name\fR
columns and/or
\fIindex_expression\fR
expressions, and an optional
\fIindex_predicate\fR\&. All
\fItable_name\fR
unique indexes that, without regard to order, contain exactly the
\fIconflict_target\fR\-specified columns/expressions are inferred (chosen) as arbiter indexes\&. If an
\fIindex_predicate\fR
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
ON CONFLICT) if such an index satisfying every other criteria is available\&. If an attempt at inference is unsuccessful, an error is raised\&.
.PP
ON CONFLICT DO UPDATE
guarantees an atomic
\fBINSERT\fR
or
\fBUPDATE\fR
outcome; provided there is no independent error, one of those two outcomes is guaranteed, even under high concurrency\&. This is also known as
UPSERT
\(em
\(lqUPDATE or INSERT\(rq\&.
.PP
\fIconflict_target\fR
.RS 4
Specifies which conflicts
ON CONFLICT
takes the alternative action on by choosing
arbiter indexes\&. Either performs
\fIunique index inference\fR, or names a constraint explicitly\&. For
ON CONFLICT DO NOTHING, it is optional to specify a
\fIconflict_target\fR; when omitted, conflicts with all usable constraints (and unique indexes) are handled\&. For
ON CONFLICT DO UPDATE, a
\fIconflict_target\fR
\fImust\fR
be provided\&.
.RE
.PP
\fIconflict_action\fR
.RS 4
\fIconflict_action\fR
specifies an alternative
ON CONFLICT
action\&. It can be either
DO NOTHING, or a
DO UPDATE
clause specifying the exact details of the
UPDATE
action to be performed in case of a conflict\&. The
SET
and
WHERE
clauses in
ON CONFLICT DO UPDATE
have access to the existing row using the table\*(Aqs name (or an alias), and to the row proposed for insertion using the special
\fIexcluded\fR
table\&.
SELECT
privilege is required on any column in the target table where corresponding
\fIexcluded\fR
columns are read\&.
.sp
Note that the effects of all per\-row
BEFORE INSERT
triggers are reflected in
\fIexcluded\fR
values, since those effects may have contributed to the row being excluded from insertion\&.
.RE
.PP
\fIindex_column_name\fR
.RS 4
The name of a
\fItable_name\fR
column\&. Used to infer arbiter indexes\&. Follows
\fBCREATE INDEX\fR
format\&.
SELECT
privilege on
\fIindex_column_name\fR
is required\&.
.RE
.PP
\fIindex_expression\fR
.RS 4
Similar to
\fIindex_column_name\fR, but used to infer expressions on
\fItable_name\fR
columns appearing within index definitions (not simple columns)\&. Follows
\fBCREATE INDEX\fR
format\&.
SELECT
privilege on any column appearing within
\fIindex_expression\fR
is required\&.
.RE
.PP
\fIcollation\fR
.RS 4
When specified, mandates that corresponding
\fIindex_column_name\fR
or
\fIindex_expression\fR
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
\fBCREATE INDEX\fR
format\&.
.RE
.PP
\fIopclass\fR
.RS 4
When specified, mandates that corresponding
\fIindex_column_name\fR
or
\fIindex_expression\fR
use particular operator class in order to be matched during inference\&. Typically this is omitted, as the
\fIequality\fR
semantics are often equivalent across a type\*(Aqs operator classes anyway, or because it\*(Aqs sufficient to trust that the defined unique indexes have the pertinent definition of equality\&. Follows
\fBCREATE INDEX\fR
format\&.
.RE
.PP
\fIindex_predicate\fR
.RS 4
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
\fBCREATE INDEX\fR
format\&.
SELECT
privilege on any column appearing within
\fIindex_predicate\fR
is required\&.
.RE
.PP
\fIconstraint_name\fR
.RS 4
Explicitly specifies an arbiter
\fIconstraint\fR
by name, rather than inferring a constraint or index\&.
.RE
.PP
\fIcondition\fR
.RS 4
An expression that returns a value of type
boolean\&. Only rows for which this expression returns
true
will be updated, although all rows will be locked when the
ON CONFLICT DO UPDATE
action is taken\&. Note that
\fIcondition\fR
is evaluated last, after a conflict has been identified as a candidate to update\&.
.RE
.PP
Note that exclusion constraints are not supported as arbiters with
ON CONFLICT DO UPDATE\&. In all cases, only
NOT DEFERRABLE
constraints and unique indexes are supported as arbiters\&.
.PP
\fBINSERT\fR
with an
ON CONFLICT DO UPDATE
clause is a
\(lqdeterministic\(rq
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\&.
.PP
Note that it is currently not supported for the
ON CONFLICT DO UPDATE
clause of an
\fBINSERT\fR
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\&.
.if n \{\
.sp
.\}
.RS 4
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.ps +1
\fBTip\fR
.ps -1
.br
.PP
It is often preferable to use unique index inference rather than naming a constraint directly using
ON CONFLICT ON CONSTRAINT
\fI constraint_name\fR\&. 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
CREATE UNIQUE INDEX \&.\&.\&. CONCURRENTLY
before dropping the index being replaced\&.
.sp .5v
.RE
.SH "OUTPUTS"
.PP
On successful completion, an
\fBINSERT\fR
command returns a command tag of the form
.sp
.if n \{\
.RS 4
.\}
.nf
INSERT \fIoid\fR \fIcount\fR
.fi
.if n \{\
.RE
.\}
.sp
The
\fIcount\fR
is the number of rows inserted or updated\&.
\fIoid\fR
is always 0 (it used to be the
OID
assigned to the inserted row if
\fIcount\fR
was exactly one and the target table was declared
WITH OIDS
and 0 otherwise, but creating a table
WITH OIDS
is not supported anymore)\&.
.PP
If the
\fBINSERT\fR
command contains a
RETURNING
clause, the result will be similar to that of a
\fBSELECT\fR
statement containing the columns and values defined in the
RETURNING
list, computed over the row(s) inserted or updated by the command\&.
.SH "NOTES"
.PP
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\&.
.PP
You may also wish to consider using
\fBMERGE\fR, since that allows mixing
\fBINSERT\fR,
\fBUPDATE\fR, and
\fBDELETE\fR
within a single statement\&. See
\fBMERGE\fR(7)\&.
.SH "EXAMPLES"
.PP
Insert a single row into table
films:
.sp
.if n \{\
.RS 4
.\}
.nf
INSERT INTO films VALUES
    (\*(AqUA502\*(Aq, \*(AqBananas\*(Aq, 105, \*(Aq1971\-07\-13\*(Aq, \*(AqComedy\*(Aq, \*(Aq82 minutes\*(Aq);
.fi
.if n \{\
.RE
.\}
.PP
In this example, the
len
column is omitted and therefore it will have the default value:
.sp
.if n \{\
.RS 4
.\}
.nf
INSERT INTO films (code, title, did, date_prod, kind)
    VALUES (\*(AqT_601\*(Aq, \*(AqYojimbo\*(Aq, 106, \*(Aq1961\-06\-16\*(Aq, \*(AqDrama\*(Aq);
.fi
.if n \{\
.RE
.\}
.PP
This example uses the
DEFAULT
clause for the date columns rather than specifying a value:
.sp
.if n \{\
.RS 4
.\}
.nf
INSERT INTO films VALUES
    (\*(AqUA502\*(Aq, \*(AqBananas\*(Aq, 105, DEFAULT, \*(AqComedy\*(Aq, \*(Aq82 minutes\*(Aq);
INSERT INTO films (code, title, did, date_prod, kind)
    VALUES (\*(AqT_601\*(Aq, \*(AqYojimbo\*(Aq, 106, DEFAULT, \*(AqDrama\*(Aq);
.fi
.if n \{\
.RE
.\}
.PP
To insert a row consisting entirely of default values:
.sp
.if n \{\
.RS 4
.\}
.nf
INSERT INTO films DEFAULT VALUES;
.fi
.if n \{\
.RE
.\}
.PP
To insert multiple rows using the multirow
\fBVALUES\fR
syntax:
.sp
.if n \{\
.RS 4
.\}
.nf
INSERT INTO films (code, title, did, date_prod, kind) VALUES
    (\*(AqB6717\*(Aq, \*(AqTampopo\*(Aq, 110, \*(Aq1985\-02\-10\*(Aq, \*(AqComedy\*(Aq),
    (\*(AqHG120\*(Aq, \*(AqThe Dinner Game\*(Aq, 140, DEFAULT, \*(AqComedy\*(Aq);
.fi
.if n \{\
.RE
.\}
.PP
This example inserts some rows into table
films
from a table
tmp_films
with the same column layout as
films:
.sp
.if n \{\
.RS 4
.\}
.nf
INSERT INTO films SELECT * FROM tmp_films WHERE date_prod < \*(Aq2004\-05\-07\*(Aq;
.fi
.if n \{\
.RE
.\}
.PP
This example inserts into array columns:
.sp
.if n \{\
.RS 4
.\}
.nf
\-\- Create an empty 3x3 gameboard for noughts\-and\-crosses
INSERT INTO tictactoe (game, board[1:3][1:3])
    VALUES (1, \*(Aq{{" "," "," "},{" "," "," "},{" "," "," "}}\*(Aq);
\-\- The subscripts in the above example aren\*(Aqt really needed
INSERT INTO tictactoe (game, board)
    VALUES (2, \*(Aq{{X," "," "},{" ",O," "},{" ",X," "}}\*(Aq);
.fi
.if n \{\
.RE
.\}
.PP
Insert a single row into table
distributors, returning the sequence number generated by the
DEFAULT
clause:
.sp
.if n \{\
.RS 4
.\}
.nf
INSERT INTO distributors (did, dname) VALUES (DEFAULT, \*(AqXYZ Widgets\*(Aq)
   RETURNING did;
.fi
.if n \{\
.RE
.\}
.PP
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:
.sp
.if n \{\
.RS 4
.\}
.nf
WITH upd AS (
  UPDATE employees SET sales_count = sales_count + 1 WHERE id =
    (SELECT sales_person FROM accounts WHERE name = \*(AqAcme Corporation\*(Aq)
    RETURNING *
)
INSERT INTO employees_log SELECT *, current_timestamp FROM upd;
.fi
.if n \{\
.RE
.\}
.PP
Insert or update new distributors as appropriate\&. Assumes a unique index has been defined that constrains values appearing in the
did
column\&. Note that the special
\fIexcluded\fR
table is used to reference values originally proposed for insertion:
.sp
.if n \{\
.RS 4
.\}
.nf
INSERT INTO distributors (did, dname)
    VALUES (5, \*(AqGizmo Transglobal\*(Aq), (6, \*(AqAssociated Computing, Inc\*(Aq)
    ON CONFLICT (did) DO UPDATE SET dname = EXCLUDED\&.dname;
.fi
.if n \{\
.RE
.\}
.PP
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
did
column:
.sp
.if n \{\
.RS 4
.\}
.nf
INSERT INTO distributors (did, dname) VALUES (7, \*(AqRedline GmbH\*(Aq)
    ON CONFLICT (did) DO NOTHING;
.fi
.if n \{\
.RE
.\}
.PP
Insert or update new distributors as appropriate\&. Example assumes a unique index has been defined that constrains values appearing in the
did
column\&.
WHERE
clause is used to limit the rows actually updated (any existing row not updated will still be locked, though):
.sp
.if n \{\
.RS 4
.\}
.nf
\-\- Don\*(Aqt update existing distributors based in a certain ZIP code
INSERT INTO distributors AS d (did, dname) VALUES (8, \*(AqAnvil Distribution\*(Aq)
    ON CONFLICT (did) DO UPDATE
    SET dname = EXCLUDED\&.dname || \*(Aq (formerly \*(Aq || d\&.dname || \*(Aq)\*(Aq
    WHERE d\&.zipcode <> \*(Aq21201\*(Aq;

\-\- Name a constraint directly in the statement (uses associated
\-\- index to arbitrate taking the DO NOTHING action)
INSERT INTO distributors (did, dname) VALUES (9, \*(AqAntwerp Design\*(Aq)
    ON CONFLICT ON CONSTRAINT distributors_pkey DO NOTHING;
.fi
.if n \{\
.RE
.\}
.PP
Insert new distributor if possible; otherwise
DO NOTHING\&. Example assumes a unique index has been defined that constrains values appearing in the
did
column on a subset of rows where the
is_active
Boolean column evaluates to
true:
.sp
.if n \{\
.RS 4
.\}
.nf
\-\- 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, \*(AqConrad International\*(Aq)
    ON CONFLICT (did) WHERE is_active DO NOTHING;
.fi
.if n \{\
.RE
.\}
.SH "COMPATIBILITY"
.PP
\fBINSERT\fR
conforms to the SQL standard, except that the
RETURNING
clause is a
PostgreSQL
extension, as is the ability to use
WITH
with
\fBINSERT\fR, and the ability to specify an alternative action with
ON CONFLICT\&. Also, the case in which a column name list is omitted, but not all the columns are filled from the
VALUES
clause or
\fIquery\fR, is disallowed by the standard\&. If you prefer a more SQL standard conforming statement than
ON CONFLICT, see
\fBMERGE\fR(7)\&.
.PP
The SQL standard specifies that
OVERRIDING SYSTEM VALUE
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\&.
.PP
Possible limitations of the
\fIquery\fR
clause are documented under
\fBSELECT\fR(7)\&.