某公司数据库面试题
某公司数据库面试题
---------------------------------------------- In database XYZ, there's a table 'run_key' with the following rows: id batch last_processed ------------------------------ 1 5 999 2 6 999 3 7 0 4 5 0 5 6 999 6 7 0 7 5 0 8 6 0 9 7 999 10 7 0
Write a SQL statement to return the number of rows with last_processed=0 for each batch.
The expected output is:
batch count ------------- 5 2 6 1 7 3
answer:
[sql] select batch,count(batch) as count from run_key where last_processed=0 group by batch;