INSERT
INSERT
INSERT - create new rows in a table
Synopsis
[ WITH [ RECURSIVE ]with_query
[, ...] ] INSERT INTOtable_name
[ ASalias
] [ (column_name
[, ...] ) ] [ OVERRIDING { SYSTEM | USER } VALUE ] { DEFAULT VALUES | VALUES ( {expression
| DEFAULT } [, ...] ) [, ...] |query
} [ ON CONFLICT [conflict_target
]conflict_action
] [ RETURNING * |output_expression
[ [ AS ]output_name
] [, ...] ] whereconflict_target
can be one of: ( {index_column_name
| (index_expression
) } [ COLLATEcollation
] [opclass
] [, ...] ) [ WHEREindex_predicate
] ON CONSTRAINTconstraint_name
andconflict_action
is one of: DO NOTHING DO UPDATE SET {column_name
= {expression
| DEFAULT } | (column_name
[, ...] ) = [ ROW ] ( {expression
| DEFAULT } [, ...] ) | (column_name
[, ...] ) = (sub-SELECT
) } [, ...] [ WHEREcondition
]
Description
INSERT
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.
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
N
column
names, if there are only
N
columns supplied by the
VALUES
clause or
query
. The values
supplied by the
VALUES
clause or
query
are
associated with the explicit or implicit column list left-to-right.
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.
If the expression for any column is not of the correct data type, automatic type conversion will be attempted.
INSERT
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 61.5
.
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.)
The optional
RETURNING
clause causes
INSERT
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's columns is allowed. The syntax of
the
RETURNING
list is identical to that of the output
list of
SELECT
. 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
condition
was not satisfied, the
row will not be returned.
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.
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
condition
.
Use of the
RETURNING
clause requires
SELECT
privilege on all columns mentioned in
RETURNING
.
If you use the
query
clause to insert rows from a
query, you of course need to have
SELECT
privilege on
any table or column used in the query.
Parameters
Inserting
This section covers parameters that may be used when only
inserting new rows. Parameters
exclusively
used with the
ON CONFLICT
clause are described
separately.
-
with_query
-
The
WITH
clause allows you to specify one or more subqueries that can be referenced by name in theINSERT
query. See Section 7.8 and SELECT for details.It is possible for the
query
(SELECT
statement) to also contain aWITH
clause. In such a case both sets ofwith_query
can be referenced within thequery
, but the second one takes precedence since it is more closely nested. -
table_name
-
The name (optionally schema-qualified) of an existing table.
-
alias
-
A substitute name for
table_name
. When an alias is provided, it completely hides the actual name of the table. This is particularly useful whenON CONFLICT DO UPDATE
targets a table namedexcluded
, since that will otherwise be taken as the name of the special table representing the row proposed for insertion. -
column_name
-
The name of a column in the table named by
table_name
. 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 withON CONFLICT DO UPDATE
, do not include the table's 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 forUPDATE
). -
OVERRIDING SYSTEM VALUE
-
Without this clause, it is an error to specify an explicit value (other than
DEFAULT
) for an identity column defined asGENERATED ALWAYS
. This clause overrides that restriction. -
OVERRIDING USER VALUE
-
If this clause is specified, then any values supplied for identity columns defined as
GENERATED BY DEFAULT
are ignored and the default sequence-generated values are applied.This clause is useful for example when copying values between tables. Writing
INSERT INTO tbl2 OVERRIDING USER VALUE SELECT * FROM tbl1
will copy fromtbl1
all columns that are not identity columns intbl2
while values for the identity columns intbl2
will be generated by the sequences associated withtbl2
. -
DEFAULT VALUES
-
All columns will be filled with their default values. (An
OVERRIDING
clause is not permitted in this form.) -
expression
-
An expression or value to assign to the corresponding column.
-
DEFAULT
-
The corresponding column will be filled with its default value.
-
query
-
A query (
SELECT
statement) that supplies the rows to be inserted. Refer to the SELECT statement for a description of the syntax. -
output_expression
-
An expression to be computed and returned by the
INSERT
command after each row is inserted or updated. The expression can use any column names of the table named bytable_name
. Write*
to return all columns of the inserted or updated row(s). -
output_name
-
A name to use for a returned column.
ON CONFLICT
Clause
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
arbiter
constraint or index specified by
conflict_target
is violated, the
alternative
conflict_action
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.
conflict_target
can perform
unique index inference
. When performing
inference, it consists of one or more
index_column_name
columns and/or
index_expression
expressions, and an optional
index_predicate
. All
table_name
unique indexes that,
without regard to order, contain exactly the
conflict_target
-specified
columns/expressions are inferred (chosen) as arbiter indexes. If
an
index_predicate
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.
ON CONFLICT DO UPDATE
guarantees an atomic
INSERT
or
UPDATE
outcome;
provided there is no independent error, one of those two outcomes
is guaranteed, even under high concurrency. This is also known as
UPSERT
-
"
UPDATE or
INSERT
"
.
-
conflict_target
-
Specifies which conflicts
ON CONFLICT
takes the alternative action on by choosing arbiter indexes . Either performs unique index inference , or names a constraint explicitly. ForON CONFLICT DO NOTHING
, it is optional to specify aconflict_target
; when omitted, conflicts with all usable constraints (and unique indexes) are handled. ForON CONFLICT DO UPDATE
, aconflict_target
must be provided. -
conflict_action
-
conflict_action
specifies an alternativeON CONFLICT
action. It can be eitherDO NOTHING
, or aDO UPDATE
clause specifying the exact details of theUPDATE
action to be performed in case of a conflict. TheSET
andWHERE
clauses inON CONFLICT DO UPDATE
have access to the existing row using the table's name (or an alias), and to the row proposed for insertion using the specialexcluded
table.SELECT
privilege is required on any column in the target table where correspondingexcluded
columns are read.Note that the effects of all per-row
BEFORE INSERT
triggers are reflected inexcluded
values, since those effects may have contributed to the row being excluded from insertion. -
index_column_name
-
The name of a
table_name
column. Used to infer arbiter indexes. FollowsCREATE INDEX
format.SELECT
privilege onindex_column_name
is required. -
index_expression
-
Similar to
index_column_name
, but used to infer expressions ontable_name
columns appearing within index definitions (not simple columns). FollowsCREATE INDEX
format.SELECT
privilege on any column appearing withinindex_expression
is required. -
collation
-
When specified, mandates that corresponding
index_column_name
orindex_expression
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. FollowsCREATE INDEX
format. -
opclass
-
When specified, mandates that corresponding
index_column_name
orindex_expression
use particular operator class in order to be matched during inference. Typically this is omitted, as the equality 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. FollowsCREATE INDEX
format. -
index_predicate
-
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
CREATE INDEX
format.SELECT
privilege on any column appearing withinindex_predicate
is required. -
constraint_name
-
Explicitly specifies an arbiter constraint by name, rather than inferring a constraint or index.
-
condition
-
An expression that returns a value of type
boolean
. Only rows for which this expression returnstrue
will be updated, although all rows will be locked when theON CONFLICT DO UPDATE
action is taken. Note thatcondition
is evaluated last, after a conflict has been identified as a candidate to update.
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.
INSERT
with an
ON CONFLICT DO UPDATE
clause is a
"
deterministic
"
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.
Note that it is currently not supported for the
ON CONFLICT DO UPDATE
clause of an
INSERT
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.
Tip
It is often preferable to use unique index inference rather than
naming a constraint directly using
ON CONFLICT ON
CONSTRAINT
constraint_name
. 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.
Outputs
On successful completion, an
INSERT
command returns a command
tag of the form
INSERToid
count
The
count
is the
number of rows inserted or updated. If
count
is exactly one, and the
target table has OIDs, then
oid
is the
OID
assigned to the inserted row. The single row must have been
inserted rather than updated. Otherwise
oid
is zero.
If the
INSERT
command contains a
RETURNING
clause, the result will be similar to that of a
SELECT
statement containing the columns and values defined in the
RETURNING
list, computed over the row(s) inserted or
updated by the command.
Notes
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.
Examples
Insert a single row into table
films
:
INSERT INTO films VALUES ('UA502', 'Bananas', 105, '1971-07-13', 'Comedy', '82 minutes');
In this example, the
len
column is
omitted and therefore it will have the default value:
INSERT INTO films (code, title, did, date_prod, kind) VALUES ('T_601', 'Yojimbo', 106, '1961-06-16', 'Drama');
This example uses the
DEFAULT
clause for
the date columns rather than specifying a value:
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');
To insert a row consisting entirely of default values:
INSERT INTO films DEFAULT VALUES;
To insert multiple rows using the multirow
VALUES
syntax:
INSERT INTO films (code, title, did, date_prod, kind) VALUES ('B6717', 'Tampopo', 110, '1985-02-10', 'Comedy'), ('HG120', 'The Dinner Game', 140, DEFAULT, 'Comedy');
This example inserts some rows into table
films
from a table
tmp_films
with the same column layout as
films
:
INSERT INTO films SELECT * FROM tmp_films WHERE date_prod < '2004-05-07';
This example inserts into array columns:
-- 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," "}}');
Insert a single row into table
distributors
, returning
the sequence number generated by the
DEFAULT
clause:
INSERT INTO distributors (did, dname) VALUES (DEFAULT, 'XYZ Widgets') RETURNING did;
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:
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;
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
excluded
table is used to reference values originally
proposed for insertion:
INSERT INTO distributors (did, dname) VALUES (5, 'Gizmo Transglobal'), (6, 'Associated Computing, Inc') ON CONFLICT (did) DO UPDATE SET dname = EXCLUDED.dname;
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:
INSERT INTO distributors (did, dname) VALUES (7, 'Redline GmbH') ON CONFLICT (did) DO NOTHING;
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):
-- 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;
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
:
-- 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;
Compatibility
INSERT
conforms to the SQL standard, except that
the
RETURNING
clause is a
PostgreSQL
extension, as is the ability
to use
WITH
with
INSERT
, 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
query
,
is disallowed by the standard.
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.
Possible limitations of the
query
clause are documented under
SELECT
.