- class="PARAMETER">column_name_index columns and/or
- expression_index
- expressions, and an optional
- index_predicate.
-
-
- All the table_name
- unique indexes that, without regard to order, contain exactly the
- specified columns/expressions and, if specified, whose predicate
- implies the
- index_predicate are chosen as arbiter indexes. Note
- that this means an index without a predicate will be used if a
- non-partial index matching every other criteria happens to be
- available.
-
-
- If no index matches the inference clause (nor is there a constraint
- explicitly named), an error is raised. Deferred constraints are
- not supported as arbiters.
-
-
-
conflict_action defines the action to be
- taken in case of conflict. 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 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 feature is also known as
- UPSERT.
-
- Note that exclusion constraints are not supported with
- ON CONFLICT DO UPDATE.
-
-
- ON CONFLICT DO UPDATE optionally accepts
- a WHERE clause condition.
- When provided, the statement only proceeds with updating if
- the condition is satisfied. Otherwise, unlike a
- conventional UPDATE, the row is still locked for update.
- Note that the condition is evaluated last, after
- a conflict has been identified as a candidate to update.
-
-
- The SET and WHERE clauses in
- ON CONFLICT UPDATE have access to the existing
- row, using the table's name, and to the row
- proposed for insertion, using the excluded
- alias. The excluded alias requires
- SELECT privilege on any column whose values are read.
-
- Note that the effects of all per-row BEFORE INSERT
- triggers are reflected in excluded values, since those
- effects may have contributed to the row being excluded from insertion.
-
-
- 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 the
- conflict-arbitrating unique index.
-
+
+ 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 the INSERT
+ query. See and
+ for details.
+
+ It is possible for the query
+ (SELECT statement)
+ to also contain a WITH clause. In such a case both
+ sets of with_query can be referenced within
+ the query, 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
+ class="PARAMETER">table_name. 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 excluded, since that's
+ also the name of the special table representing rows proposed
+ for insertion.
+
+
+
+
+
+
+ column_name
+
+ The name of a column in the table named by
+ class="PARAMETER">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 with ON CONFLICT DO UPDATE, do not include
+ the table's name in the specification of a target column. For
+ example, INSERT ... ON CONFLICT DO UPDATE tab SET
+ table_name.col = 1 is invalid (this follows the general
+ behavior for UPDATE).
+
+
+
+
+
+ DEFAULT VALUES
+
+ All columns will be filled with their default values.
+
+
+
+
+
+ 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
+
+ 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 by
+ class="PARAMETER">table_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
+ class="PARAMETER">column_name_index columns and/or
+ expression_index
+ expressions, and an optional
+ index_predicate. All
+ class="PARAMETER">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. For
+ ON CONFLICT DO NOTHING, it is optional to
+ specify a
conflict_target; when
+ omitted, conflicts with all usable constraints (and unique
+ indexes) are handled. For ON CONFLICT DO
+ UPDATE, a
conflict_target+ must be provided.
+
+
+
+
+
+ conflict_action
+
+
conflict_action 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's name (or an alias), and to rows proposed for insertion
+ using the special excluded table.
+ SELECT privilege is required on any column in the
+ target table where corresponding excluded
+ columns are read.
+
+ Note that the effects of all per-row BEFORE
+ INSERT triggers are reflected in
+ excluded values, since those effects may
+ have contributed to the row being excluded from insertion.
+
+
+
+
+
+ column_name_index
+
+ The name of a
+ class="PARAMETER">table_name column. Used to
+ infer arbiter indexes. Follows CREATE
+ INDEX format. SELECT privilege on
+ column_name_index
+ is required.
+
+
+
+
+
+ expression_index
+
+ Similar to
+ class="PARAMETER">column_name_index, but used to
+ infer expressions on
+ class="PARAMETER">table_name columns appearing
+ within index definitions (not simple columns). Follows
+ CREATE INDEX format. SELECT
+ privilege on any column appearing within
+ class="PARAMETER">expression_index is required.
+
+
+
+
+
+ collation
+
+ When specified, mandates that corresponding
+ class="PARAMETER">column_name_index or
+ expression_index
+ 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 CREATE INDEX format.
+
+
+
+
+
+ opclass
+
+ When specified, mandates that corresponding
+ class="PARAMETER">column_name_index or
+ expression_index
+ 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. Follows CREATE
+ 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 within
+ class="PARAMETER">index_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
+ returns true will be updated, although all
+ rows will be locked when the ON CONFLICT DO UPDATE
+ action is taken. Note that
+ condition 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 exclusion constraints are
+ not supported with ON CONFLICT DO UPDATE.
+
+
+ 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.
+
+
+
+
Insert or update new distributors as appropriate. Assumes a unique
index has been defined that constrains values appearing in the
- did column. Note that an EXCLUDED
- expression is used to reference values originally proposed for
- insertion:
+ 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')
+ VALUES (5, 'Gizmo Transglobal'), (6, 'Associated Computing, Inc')
ON CONFLICT (did) DO UPDATE SET dname = EXCLUDED.dname;
projects / postgresql.git / commitdiff