Table Operations

CREATE TABLE

Create a new table from a sequence of column definitions, a SQL query executed against an existing table, or create an empty table from the schema of an existing table.

Example:

CREATE TABLE tbl(colx VARCHAR, coly DATE, colz ARRAY<DOUBLE>)

CREATE TABLE new_table AS
SELECT * FROM existing_table WHERE value > 42

CREATE TABLE new_table LIKE existing_table

DELETE

Remove specific rows from a table using an (optional) constraint. Omitting the constraint deletes all rows, equivalent to TRUNCATE.

Example:

DELETE FROM some_table WHERE value < 0

DROP TABLES

Deletes the specified table, unregistering it. Dropping a table that does not exist raises an error unless the optional IF EXISTS clause is given, in which case the statement is a no-op.

Example:

DROP TABLE actual_table
DROP TABLE IF EXISTS possible_table

EXPLAIN

Returns the Polars execution plan for a given SQL query.

Example:

EXPLAIN SELECT * FROM some_table

SHOW TABLES

Returns a list of all tables registered in the given context.

Example:

SHOW TABLES

UNNEST

Unnest one or more arrays as columns in a new table object.

Example:

SELECT * FROM
  UNNEST(
    [1, 2, 3, 4],
    ['ww','xx','yy','zz'],
    [23.0, 24.5, 28.0, 27.5]
  ) AS tbl (x,y,z)

TRUNCATE

Remove all data from a table without deleting the table itself. Truncating a table that does not exist raises an error unless the optional IF EXISTS clause is given, in which case the statement is a no-op.

Example:

TRUNCATE TABLE actual_table
TRUNCATE TABLE IF EXISTS possible_table