SET VARIABLE my_var = 30;
SELECT 20 + getvariable('my_var') AS total;

SET VARIABLE my_var = 30;
SET VARIABLE my_var = 100;
SELECT 20 + getvariable('my_var') AS total;

SET VARIABLE my_date = DATE '2018-07-13';
SET VARIABLE my_string = 'Hello world';
SET VARIABLE my_map = MAP {'k1': 10, 'k2': 20};

-- write some CSV files
COPY (SELECT 42 AS a) TO 'test1.csv';
COPY (SELECT 84 AS a) TO 'test2.csv';

-- add a list of CSV files to a table
CREATE TABLE csv_files (file VARCHAR);
INSERT INTO csv_files VALUES ('test1.csv'), ('test2.csv');

-- initialize a variable with the list of csv files
SET VARIABLE list_of_files = (SELECT list(file) FROM csv_files);

-- read the CSV files
SELECT * FROM read_csv(getvariable('list_of_files'), filename := True);

SELECT getvariable('undefined_var') AS result;

SET VARIABLE column_to_exclude = 'col1';
CREATE TABLE tbl AS SELECT 12 AS col0, 34 AS col1, 56 AS col2;
SELECT COLUMNS(c -> c != getvariable('column_to_exclude')) FROM tbl;

SET VARIABLE my_var = 30;
RESET VARIABLE my_var;
SELECT getvariable('my_var') AS my_var;