项目中需要比对两种方法计算生成的数据情况,需要做两件事情,比对生成的中间表的行数是否相同,比对最后一张表的数据是否一致. 在获取表的数据量是一条一条地使用select count(*) from table来获取等待结果比较烦人,所以就写了一个bash shell来做这件事. 但一开始是这样的: for line in $(cat tables.txt) do echo "tablename :$line"; value=$(hive --database databasename -
Strings can easily be written to and read from a file. Numbers take a bit more effort, since the read() method only returns strings, which will have to be passed to a function like int(), which takes a string like '123' and returns its numeric value
UPDATE table1 t1 SET (name, desc) = (SELECT t2.name, t2.desc FROM table2 t2 WHERE t1.id = t2.id) WHERE EXISTS ( FROM table2 t2 WHERE t1.id = t2.id ) Assuming the join results in a key-preserved view, you could also UPDATE (SELECT t1.id, t1.name name1