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 60.5. 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
If 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 VALUE
orOVERRIDING USER VALUE
. (For an identity column defined asGENERATED BY DEFAULT
,OVERRIDING SYSTEM VALUE
is the normal behavior and specifying it does nothing, but PostgreSQL allows it as an extension.)OVERRIDING USER VALUE
If 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 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, as if
DEFAULT
were explicitly specified for each column. (AnOVERRIDING
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. 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.
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. 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) 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.
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 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 Postgres Pro 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. Postgres Pro allows the clause in any case and ignores it if it is not applicable.
Possible limitations of the query
clause are documented under SELECT.