摘要： #!/bin/bash # 判断参数个数 if [ $# -lt 1 ] then echo "使用方法: ./myhadoop.sh {start|stop}" exit fi case $1 in "start") echo " 启动 Hadoop 集群 " echo " 启动 HDFS " # 阅读全文

摘要： SELECT T.sname,T.ctfid,T.gender,t.address, count(*) OVER(PARTITION BY T.sname) AS FM_CNT FROM test_db.room3 T WHERE T.address like "%北京%" AND instr(T. 阅读全文