Insert Statement
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The INSERT statement inserts new data into a table.

Examples

-- insert the values (1), (2), (3) into "tbl"
INSERT INTO tbl VALUES (1), (2), (3);
-- insert the result of a query into a table
INSERT INTO tbl SELECT * FROM other_tbl;
-- insert values into the "i" column, inserting the default value into other columns
INSERT INTO tbl(i) VALUES (1), (2), (3);
-- explicitly insert the default value into a column
INSERT INTO tbl(i) VALUES (1), (DEFAULT), (3);
-- assuming tbl has a primary key/unique constraint, do nothing on conflict
INSERT OR IGNORE tbl(i) VALUES(1);
-- or update the table with the new values instead
INSERT OR REPLACE tbl(i) VALUES(1);

Syntax

INSERT INTO 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. The values supplied by the VALUES clause or query are associated with the 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.

On Conflict Clause

An ON CONFLICT clause can be used to perform a certain action on conflicts that arise from UNIQUE or PRIMARY KEY constraints.

Optionally you can provide a conflict_target, which is a group of columns that an Index indexes on, or if left out, all UNIQUE or PRIMARY KEY constraint(s) on the table are targeted.

When a conflict target is provided, you can further filter this with a WHERE clause, that should be met by all conflicts. If a conflict does not meet this condition, an error will be thrown instead, and the entire operation is aborted.

Because we need a way to refer to both the to-be-inserted tuple and the existing tuple, we introduce the special excluded qualifier. When the excluded qualifier is provided, the reference refers to the to-be-inserted tuple, otherwise it refers to the existing tuple This special qualifier can be used within the WHERE clauses and SET expressions of the ON CONFLICT clause.

There are two supported actions:

  1. DO NOTHING
    Causes the error(s) to be ignored, and the values are not inserted or updated.

  2. DO UPDATE
    Causes the INSERT to turn into an UPDATE on the conflicting row(s) instead.
    The SET expressions that follow determine how these rows are updated.
    Optionally you can provide an additional WHERE clause that can exclude certain rows from the update.
    The conflicts that don’t meet this condition are ignored instead.

INSERT OR REPLACE is a shorter syntax alternative to ON CONFLICT DO UPDATE SET (c1 = excluded.c1, c2 = excluded.c2, ..).
It updates every column of the existing row to the new values of the to-be-inserted row.

INSERT OR IGNORE is a shorter syntax alternative to ON CONFLICT DO NOTHING.

Returning Clause

The RETURNING clause may be used to return the contents of the rows that were inserted. This can be useful if some columns are calculated upon insert. For example, if the table contains an automatically incrementing primary key, then the RETURNING clause will include the automatically created primary key. This is also useful in the case of generated columns.

Some or all columns can be explicitly chosen to be returned and they may optionally be renamed using aliases. Arbitrary non-aggregating expressions may also be returned instead of simply returning a column. All columns can be returned using the * expression, and columns or expressions can be returned in addition to all columns returned by the *.

-- A basic example to show the syntax
CREATE TABLE t1(i INT);
INSERT INTO t1 
    SELECT 1 
    RETURNING *;
i
1
-- A more complex example that includes an expression in the RETURNING clause
CREATE TABLE t2(i INT, j INT);
INSERT INTO t2 
    SELECT 2 as i, 3 as j 
    RETURNING *, i * j as i_times_j;
i j i_times_j
2 3 6

This example shows a situation where the RETURNING clause is more helpful. First, a table is created with a primary key column. Then a sequence is created to allow for that primary key to be incremented as new rows are inserted. When we insert into the table, we do not already know the values generated by the sequence, so it is valuable to return them. For additional information, see the Create Sequence documentation.

CREATE TABLE t3(i INT PRIMARY KEY, j INT);
CREATE SEQUENCE 't3_key';
INSERT INTO t3 
    SELECT nextval('t3_key') as i, 42 as j 
    UNION ALL
    SELECT nextval('t3_key') as i, 43 as j
    RETURNING *;
i j
1 42
2 43
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