获取指定hive库的schema

指定要导出的cloudera数据库，执行脚本：

#! /bin/bash
echo "hive test..."

# 读取表create table
funCreateTable(){
 echo "-- --------------$2" >> create_table_first.txt
  echo "use  $1;" >> create_table_first.txt
 	echo "drop table if exists  $2;" >> create_table_first.txt
 	
   hive -e "use $1; show create table $2;" >> create_table_first.txt
   sed -e '/WARN/d'  create_table_first.txt > create_table.txt
   
		echo ";" >> create_table.txt
		echo "msck repair table  $2;" >> create_table.txt
		
   cat create_table.txt >> $3
   
   rm create_table.txt
   rm create_table_first.txt
}

# 读取 db下的所有表
funReadTable(){
hive -e "use $1; show tables" >> hivetablesfirst.txt
sed -e '/WARN/d'  hivetablesfirst.txt > hivetables.txt
rm hivetablesfirst.txt
}


# 读取db下的所有 table strunct
funReadDBCreateTable(){
  file="$1.sql"
  
	funReadTable $1
	
	if [ -f "hivetables.txt" ]; then
	
	cat hivetables.txt | while read eachline
	
	do
	  funCreateTable $1 $eachline $file
	done
	
	fi
	  
	rm hivetables.txt
}

# 主程序
funReadDBCreateTable cloudera

# 上传到HDFS
while true
do
        if [ ! -f "asmp.sql" ]; then
        echo "sorry,waiting for file is created..."
        sleep 10
        else
		hdfs dfs -put *.sql /user/lhx/test
        rm -rf asmp.sql
        echo "end hive test!" 
        break;
        fi
done

执行结果：

--------------test_to_hive
use  cloudera;
drop table if exists  test_to_hive;
CREATE TABLE `test_to_hive`(
  `s1` string COMMENT '', 
  `s2` string COMMENT '')
ROW FORMAT SERDE 
  'org.apache.hadoop.hive.serde2.avro.AvroSerDe' 
STORED AS INPUTFORMAT 
  'org.apache.hadoop.hive.ql.io.avro.AvroContainerInputFormat' 
OUTPUTFORMAT 
  'org.apache.hadoop.hive.ql.io.avro.AvroContainerOutputFormat'
LOCATION
  'hdfs://bigdata01.lhx.com:8020/user/hive/warehouse/cloudera.db/test_to_hive'
TBLPROPERTIES (
  'transient_lastDdlTime'='1538116496')
;
msck repair table  test_to_hive;
-- --------------test_to_hive2
use  cloudera;
drop table if exists  test_to_hive2;
CREATE TABLE `test_to_hive2`(
  `name` string COMMENT '', 
  `age` int COMMENT '', 
  `id` int COMMENT '', 
  `type` string COMMENT '', 
  `database` string COMMENT '', 
  `table` string COMMENT '')
ROW FORMAT SERDE 
  'org.apache.hadoop.hive.serde2.avro.AvroSerDe' 
STORED AS INPUTFORMAT 
  'org.apache.hadoop.hive.ql.io.avro.AvroContainerInputFormat' 
OUTPUTFORMAT 
  'org.apache.hadoop.hive.ql.io.avro.AvroContainerOutputFormat'
LOCATION
  'hdfs://bigdata01.lhx.com:8020/user/hive/warehouse/cloudera.db/test_to_hive2'
TBLPROPERTIES (
  'transient_lastDdlTime'='1539583665')
;
msck repair table  test_to_hive2;