Biq Query - Count - google-bigquery

Question

I have table that displays
ID employeename Supervisorname
Need to display another column CountD: count of employee for the direct supervior,CountI which shows the count of employee indirect
Snapshot sharedenter image description here
Tried Count (*) over partition by Supervisorname but didnot help

Answer 1

Below is for BigQuery Standard SQL
Try below script
#standardSQL
DECLARE rows_count, run_away_stop INT64 DEFAULT 0;
CREATE TEMP TABLE input AS (
SELECT 1 id, 'A' employee, 'X' supervisor UNION ALL
SELECT 2, 'B', 'X' UNION ALL
SELECT 3, 'C', 'X' UNION ALL
SELECT 4, 'X', 'F' UNION ALL
SELECT 5, 'Y', 'F' UNION ALL
SELECT 6, 'F', 'G'
);
CREATE TEMP TABLE ttt AS SELECT supervisor, employee FROM input;
LOOP
SET (rows_count, run_away_stop) = ((SELECT COUNT(1) FROM ttt), run_away_stop + 1);
CREATE OR REPLACE TEMP TABLE ttt AS
SELECT supervisor, employee FROM ttt UNION DISTINCT
SELECT t1.supervisor, t2.employee
FROM input t1 JOIN ttt t2
ON t1.employee = t2.supervisor;
IF rows_count = (SELECT COUNT(1) FROM ttt) OR run_away_stop > 10 THEN BREAK; END IF;
END LOOP;
SELECT t1.*,
IFNULL(direct_employees, 0) AS direct_employees,
IFNULL(all_employees, 0) AS all_employees
FROM input t1
LEFT JOIN (
SELECT supervisor, COUNT(1) direct_employees
FROM input GROUP BY supervisor
) t2 ON t1.employee = t2.supervisor
LEFT JOIN (
SELECT supervisor, COUNT(1) all_employees
FROM ttt GROUP BY supervisor
) t3 ON t1.employee = t3.supervisor
ORDER BY 1;
it returns desired output
To apply to your real table
Remove CREATE TEMP TABLE input AS ( ... ) statement
Instead of input table use your real table reference as your_project.your_dataset.your_table
Also, take attention to run_away_stop > 10 expression - it takes care of loop running not more that 10 times - you can tune this number based on how deep hierarchy in your data
As an option - you can try use Array instead of Temp table as in example below
#standardSQL
DECLARE rows_count, run_away_stop INT64 DEFAULT 0;
DECLARE ttt ARRAY<STRUCT<supervisor STRING, employee STRING>> DEFAULT [];
CREATE TEMP TABLE input AS (
SELECT 1 id, 'A' employee, 'X' supervisor UNION ALL
SELECT 2, 'B', 'X' UNION ALL
SELECT 3, 'C', 'X' UNION ALL
SELECT 4, 'X', 'F' UNION ALL
SELECT 5, 'Y', 'F' UNION ALL
SELECT 6, 'F', 'G'
);
SET ttt = ARRAY(SELECT AS STRUCT supervisor, employee FROM input);
LOOP
SET (rows_count, run_away_stop) = (ARRAY_LENGTH(ttt), run_away_stop + 1);
SET ttt = ARRAY(
SELECT AS STRUCT * FROM (
SELECT supervisor, employee FROM UNNEST(ttt) UNION DISTINCT
SELECT t1.supervisor, t2.employee
FROM input t1 JOIN UNNEST(ttt) t2
ON t1.employee = t2.supervisor
));
IF rows_count = ARRAY_LENGTH(ttt) OR run_away_stop > 10 THEN BREAK; END IF;
END LOOP;
SELECT t1.*,
IFNULL(direct_employees, 0) AS direct_employees,
IFNULL(all_employees, 0) AS all_employees
FROM input t1
LEFT JOIN (
SELECT supervisor, COUNT(1) direct_employees
FROM input GROUP BY supervisor
) t2 ON t1.employee = t2.supervisor
LEFT JOIN (
SELECT supervisor, COUNT(1) all_employees
FROM UNNEST(ttt) GROUP BY supervisor
) t3 ON t1.employee = t3.supervisor
ORDER BY 1;