INSERT INTO FROM SELECT Statement

Important

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Confluent Cloud for Apache Flink®️ enables inserting SELECT query results directly into a Flink SQL table.

Syntax

[EXECUTE] INSERT { INTO | OVERWRITE } [catalog_name.][database_name.]table_name
  [PARTITION (partition_column_name1=value1 [, partition_column_name2=value2, ...])]
  [(column_name1 [, column_name2, ...])]
  select_statement
OVERWRITE
INSERT OVERWRITE overwrites all existing data in the table or partition. New records are appended.
PARTITION
The PARTITION clause contains static partition columns for the insertion.
COLUMN LIST

For a table T(a INT, b INT, c INT), Flink SQL supports

INSERT INTO T(c, b) SELECT x, y FROM S.

The x result is written to column c, and the y result is written to column b. If column a is nullable, a is set to NULL.

Description

Insert query results into a table.

Use the INSERT INTO FROM SELECT statement to insert rows into a table from another table or query.

For example, if you have a table T with columns a, b, and c, and another table S with columns x and y, the following query writes the values of x and y from S into c and b of T, respectively.

INSERT INTO T (c, b) SELECT x, y FROM S

If column a of T is nullable, Flink SQL sets it to NULL.

Example

In the Flink SQL shell or in a Cloud Console workspace, run the following commands to see an example of the INSERT INTO FROM SELECT statement.

  1. Create a table for web page click events.

    -- Create a table for web page click events.
    CREATE TABLE clicks (
      ip_address VARCHAR,
      url VARCHAR,
      click_ts_raw BIGINT
    );
    
  2. Populate the table with mock clickstream data.

    -- Populate the table with mock clickstream data.
    INSERT INTO clicks
    VALUES( '10.0.0.1',  'https://acme.com/index.html',     1692812175),
          ( '10.0.0.12', 'https://apache.org/index.html',   1692826575),
          ( '10.0.0.13', 'https://confluent.io/index.html', 1692826575),
          ( '10.0.0.1',  'https://acme.com/index.html',     1692812175),
          ( '10.0.0.12', 'https://apache.org/index.html',   1692819375),
          ( '10.0.0.13', 'https://confluent.io/index.html', 1692826575);
    

    Press ENTER to return to the SQL shell. Because INSERT INTO VALUES is a point-in-time statement, it exits after it completes inserting records.

  3. Create another table for filtered web page click events.

    CREATE TABLE filtered_clicks (
      ip_address VARCHAR,
      url VARCHAR,
      click_ts_raw BIGINT
    );
    
  4. Run the following statement to insert filtered rows into the filtered_clicks table. Only clicks that have an IP address of 10.0.0.1 are inserted.

    INSERT INTO filtered_clicks(
      ip_address,
      url,
      click_ts_raw
    )
    SELECT * FROM clicks WHERE ip_address = '10.0.0.1';
    
  5. View the rows in the filtered_clicks table.

    SELECT * FROM filtered_clicks;
    

    Your output should resemble:

    ip_address url                         click_timestamp
    10.0.0.1   https://acme.com/index.html 2023-08-23 10:36:15
    10.0.0.1   https://acme.com/index.html 2023-08-23 10:36:15