# INSERT Inserting data for a row is done using an `INSERT` statement: ```cql insert_statement: INSERT INTO table_name ( `names_values` | `json_clause` ) : [ IF NOT EXISTS ] : [ USING `update_parameter` ( AND `update_parameter` )* ]; names_values: `names` VALUES `tuple_literal` json_clause: JSON `string` [ DEFAULT ( NULL | UNSET ) ] names: '(' `column_name` ( ',' `column_name` )* ')' update_parameter: ( TIMESTAMP `int_value` | TTL `int_value` | TIMEOUT `duration` ) int_value: ( `integer` | `bind_marker` ) ``` For example: ```cql INSERT INTO NerdMovies (movie, director, main_actor, year) VALUES ('Serenity', 'Joss Whedon', 'Nathan Fillion', 2005) IF NOT EXISTS USING TTL 86400; ``` The `INSERT` statement writes one or more columns for a given row in a table. Note that since a row is identified by its `PRIMARY KEY`, at least the columns composing it must be specified. The list of columns to insert to must be supplied when using the `VALUES` syntax. Note that unlike in SQL, `INSERT` does not check the prior existence of the row by default: the row is created if none existed before, and updated otherwise. Furthermore, there is no means to know which of creation or update happened. All updates of an `INSERT` are applied atomically, meaning the statement can not have a partial effect on database state. It can, however, leave some of the columns unchanged due to the semantics of eventual consistency on an event of a timestamp collision: `INSERT` statements happening concurrently at different cluster nodes proceed without coordination. Eventually cell values supplied by a statement with the highest timestamp will prevail (see [update ordering](https://docs.scylladb.com/manual/master/cql/dml.md#update-ordering)). Unless a timestamp is provided by the client, ScyllaDB will automatically generate a timestamp with microsecond precision for each column assigned by `INSERT`. ScyllaDB ensures timestamps created by the same node are unique. Timestamps assigned at different nodes are not guaranteed to be globally unique. With a steadily high write rate timestamp collision is not unlikely. If it happens, i.e. two `INSERTS` have the same timestamp, a conflict resolution algorithm determines which of the inserted cells prevails (see [update ordering](https://docs.scylladb.com/manual/master/cql/dml.md#update-ordering)). Please refer to the [update parameters](https://docs.scylladb.com/manual/master/cql/dml.md#update-parameters) section for more information on the `update_parameter`. ```cql INSERT INTO NerdMovies (movie, director, main_actor) VALUES ('Serenity', 'Anonymous', 'Unknown') USING TIMESTAMP 1442880000000000; INSERT INTO NerdMovies (movie, director, main_actor) VALUES ('Serenity', 'Joseph Whedon', 'Nathan Fillion') USING TIMESTAMP 1442880000000000; SELECT movie, director, main_actor FROM NerdMovies WHERE movie = 'Serenity' ``` ```none movie | director | main_actor ----------+---------------+------------ Serenity | Joseph Whedon | Unknown ``` `INSERT` is not required to assign all columns, so if two statements modify the same primary key but assign different columns effects of both statements are preserved: ```cql INSERT INTO NerdMovies (movie, director, main_actor) VALUES ('Serenity', 'Joss Whedon', 'Nathan Fillion'); INSERT INTO NerdMovies (movie, director, year) VALUES ('Serenity', 'Josseph Hill Whedon', 2005); SELECT * FROM NerdMovies WHERE movie = 'Serenity' ``` ```none ╭─────────┬───────────────────┬──────────────┬─────╮ │movie │director │main_actor │year │ ├─────────┼───────────────────┼──────────────┼─────┤ │Serenity │Joseph Hill Whedon │Nathan Fillion│2005 │ ╰─────────┴───────────────────┴──────────────┴─────╯ ``` Also note that `INSERT` does not support counters, while `UPDATE` does. #### NOTE You can use the `IF NOT EXISTS` condition with the `INSERT` statement. When this is used, the insert is only made if the row does not exist prior to the insertion. Each such `INSERT` gets a globally unique timestamp. Using `IF NOT EXISTS` incurs a non-negligible performance cost (internally, as Paxos will be used), so use `IF NOT EXISTS` wisely. If [enabled](https://docs.scylladb.com/manual/master/cql/ddl.md#cdc-options) on a table, you can use UPDATE, INSERT, and DELETE statements with Change Data Capture (CDC) tables. [Apache Cassandra Query Language (CQL) Reference](https://docs.scylladb.com/manual/master/cql/index.md) Copyright © 2016, The Apache Software Foundation. Apache®, Apache Cassandra®, Cassandra®, the Apache feather logo and the Apache Cassandra® Eye logo are either registered trademarks or trademarks of the Apache Software Foundation in the United States and/or other countries. No endorsement by The Apache Software Foundation is implied by the use of these marks.