null值与任意值比较时都为fasle
not in 、"!"、"not like"条件过滤都会过滤掉null值的数据
SELECT * from temp; SELECT * from temp where score not in (70); 返回null解决方法:
SELECT * from temp where score not in (70) or score is null;SELECT…
详情可以查看添加链接描述
1.安装jdk
apt-get install openjdk-8-jdk2.安装单机zookeeper
# 下载
#https://downloads.apache.org/zookeeper/zookeeper-3.7.1/apache-zookeeper-3.7.1.tar.gz
# 用这个包启动的时候会报错Error: Could not find or load main class org.apach…