1. 执行语句,创建3张表
CREATE TABLE table_dev1 (id serial NOT NULL,devicecode text NULL, -- 设备idopenflag int4 NULL -- 是否启动 1:启动, 0:未启动
);CREATE TABLE table_dev2 (id serial NOT NULL,devicecode text NULL, -…
一、原题 Using the CUSTOMERS table, you need to generate a report that shows 50% of each credit amount in each income level. The report should NOT show any repeated credit amounts in each income level.Which query would give the required result?A. SELECT …