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 [ WITH ( { OLD | NEW } ASoutput_alias[, ...] ) ] { * |output_expression[ [ AS ]output_name] } [, ...] ] whereconflict_targetcan be one of: ( {index_column_name| (index_expression) } [ COLLATEcollation] [opclass] [, ...] ) [ WHEREindex_predicate] ON CONSTRAINTconstraint_nameandconflict_actionis one of: DO NOTHING DO SELECT [ FOR { UPDATE | NO KEY UPDATE | SHARE | KEY SHARE } ] [ WHEREcondition] 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 63.5.
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 selected or updated, if an ON CONFLICT DO SELECT/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, updated, or selected will be returned. For example, if a row was
locked but not updated or selected because an ON CONFLICT ...
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 ON CONFLICT DO SELECT is present,
SELECT privilege on the table is required.
If ON CONFLICT DO SELECT FOR UPDATE/SHARE is used,
UPDATE privilege is required on at least one
column, in addition to SELECT privilege.
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, all forms of ON CONFLICT
also require SELECT privilege on any column whose values
are read. This includes any column mentioned in
conflict_target (including columns referred to
by the arbiter constraint), and any column mentioned in an
ON CONFLICT DO UPDATE expression,
or a WHERE clause 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_queryThe
WITHclause allows you to specify one or more subqueries that can be referenced by name in theINSERTquery. See Section 7.8 and SELECT for details.It is possible for the
query(SELECTstatement) to also contain aWITHclause. In such a case both sets ofwith_querycan be referenced within thequery, but the second one takes precedence since it is more closely nested.table_nameThe name (optionally schema-qualified) of an existing table.
aliasA 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 UPDATEtargets a table namedexcluded, since that will otherwise be taken as the name of the special table representing the row proposed for insertion.column_nameThe 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 = 1is invalid (this follows the general behavior forUPDATE).OVERRIDING SYSTEM VALUEIf this clause is specified, then any values supplied for identity columns will override the default sequence-generated values.
For an identity column defined as
GENERATED ALWAYS, it is an error to insert an explicit value (other thanDEFAULT) without specifying eitherOVERRIDING SYSTEM VALUEorOVERRIDING USER VALUE. (For an identity column defined asGENERATED BY DEFAULT,OVERRIDING SYSTEM VALUEis the normal behavior and specifying it does nothing, but PostgreSQL allows it as an extension.)OVERRIDING USER VALUEIf this clause is specified, then any values supplied for identity columns 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 tbl1will copy fromtbl1all columns that are not identity columns intbl2while values for the identity columns intbl2will be generated by the sequences associated withtbl2.DEFAULT VALUESAll columns will be filled with their default values, as if
DEFAULTwere explicitly specified for each column. (AnOVERRIDINGclause is not permitted in this form.)expressionAn expression or value to assign to the corresponding column.
DEFAULTThe 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.
queryA query (
SELECTstatement) that supplies the rows to be inserted. Refer to the SELECT statement for a description of the syntax.output_aliasAn optional substitute name for
OLDorNEWrows in theRETURNINGlist.By default, old values from the target table can be returned by writing
OLD.orcolumn_nameOLD.*, and new values can be returned by writingNEW.orcolumn_nameNEW.*. When an alias is provided, these names are hidden and the old or new rows must be referred to using the alias. For exampleRETURNING WITH (OLD AS o, NEW AS n) o.*, n.*.output_expressionAn expression to be computed and returned by the
INSERTcommand 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).A column name or
*may be qualified usingOLDorNEW, or the correspondingoutput_aliasforOLDorNEW, to cause old or new values to be returned. An unqualified column name, or*, or a column name or*qualified using the target table name or alias will return new values.For a simple
INSERT, all old values will beNULL. However, for anINSERTwith anON CONFLICT DO SELECT/UPDATEclause, the old values may be non-NULL(when the row proposed for insertion conflicts with an existing row). If theSELECTpath is taken, the new values will be identical to the old values, since no modification takes place.output_nameA 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.
ON CONFLICT DO SELECT returns the existing row
that conflicts with the row proposed for insertion, optionally
with row-level locking.
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”.
ON CONFLICT DO SELECT similarly allows an atomic
INSERT or SELECT outcome. This
is also known as idempotent insert or
get or create. For ON CONFLICT DO
SELECT, a RETURNING clause
must be provided.
conflict_targetSpecifies which conflicts
ON CONFLICTtakes 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 UPDATEandON CONFLICT DO SELECT, aconflict_targetmust be provided.conflict_actionconflict_actionspecifies an alternativeON CONFLICTaction. It can beDO NOTHING, aDO SELECTclause that allows conflicting rows to be returned, or aDO UPDATEclause specifying the exact details of theUPDATEaction to be performed in case of a conflict.The
SETclause inDO UPDATEand theWHEREclause in bothDO SELECTandDO UPDATEhave access to the existing row using the table's name (or an alias), and to the row proposed for insertion using the specialexcludedtable.SELECTprivilege is required on any column in the target table where correspondingexcludedcolumns are read.Note that the effects of all per-row
BEFORE INSERTtriggers are reflected inexcludedvalues, since those effects may have contributed to the row being excluded from insertion.index_column_nameThe name of a
table_namecolumn. Used to infer arbiter indexes. FollowsCREATE INDEXformat.SELECTprivilege onindex_column_nameis required.index_expressionSimilar to
index_column_name, but used to infer expressions ontable_namecolumns appearing within index definitions (not simple columns). FollowsCREATE INDEXformat.SELECTprivilege on any column appearing withinindex_expressionis required.collationWhen specified, mandates that corresponding
index_column_nameorindex_expressionuse 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 INDEXformat.opclassWhen specified, mandates that corresponding
index_column_nameorindex_expressionuse 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 INDEXformat.index_predicateUsed 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 INDEXformat.SELECTprivilege on any column appearing withinindex_predicateis required.constraint_nameExplicitly specifies an arbiter constraint by name, rather than inferring a constraint or index.
FOR UPDATEFOR NO KEY UPDATEFOR SHAREFOR KEY SHAREWhen specified in an
ON CONFLICT DO SELECTclause, conflicting table rows are locked against concurrent updates. See The Locking Clause in the SELECT documentation.conditionAn expression that returns a value of type
boolean. Only rows for which this expression returnstruewill be updated or selected for return, although all conflicting rows will be locked whenON CONFLICT DO UPDATEorON CONFLICT DO SELECT FOR UPDATE/SHAREis specified. Note thatconditionis evaluated last, after a conflict has been identified as a candidate to update or select.
Note that exclusion constraints are not supported as arbiters with
ON CONFLICT DO SELECT/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
INSERToidcount
The count is the number of
rows inserted, updated, or selected for return. oid is always 0 (it
used to be the OID assigned to the inserted row if
count was exactly one and the target table was
declared WITH OIDS and 0 otherwise, but creating a table
WITH OIDS is not supported anymore).
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) affected 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.
You may also wish to consider using MERGE, since that
allows mixing INSERT, UPDATE, and
DELETE within a single statement.
See MERGE.
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 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 old_did
and old_dname will be NULL for
non-conflicting rows:
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;
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 return the existing
distributor row. Example assumes a unique index has been defined
that constrains values appearing in the did column.
This is useful for get-or-create patterns:
INSERT INTO distributors (did, dname) VALUES (11, 'Global Electronics')
ON CONFLICT (did) DO SELECT
RETURNING *;
Insert a new distributor if the ID doesn't match, otherwise return the existing row, if its name doesn't match:
INSERT INTO distributors AS d (did, dname) VALUES (12, 'Micro Devices Inc')
ON CONFLICT (did) DO SELECT WHERE d.dname != EXCLUDED.dname
RETURNING *;
Insert a new distributor or return and lock the existing row for update. This is useful when you need to ensure exclusive access to the row:
INSERT INTO distributors (did, dname) VALUES (13, 'Advanced Systems')
ON CONFLICT (did) DO SELECT FOR UPDATE
RETURNING *;
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. If you prefer a more SQL standard
conforming statement than ON CONFLICT, see
MERGE.
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.
Report a documentation issue
Read the upstream documentation. For corrections, first check the current manual.