获取impala下所有的数据库建表语句

本博文介绍三种方法，推荐使用第三种，前两种都是尝试。

方法一：

现在的导出还是有缺陷的，导出的文件中还是存在其他不必要的信息

#!/bin/bash
##获取数据库
databases=$(hive -e "show databases; exit;")
for database in $databases;
do
#获取hive建表语句
tables=$(hive -e "use $database; show tables;")
 for table in $tables;
 do
 echo "--=========== db: $database , table: $table ===========" >> $database.sql
 echo "$(hive -e "use $database;show create table $table;");" >> $database.sql
 done
done

还没有找到其他方法。有其他解决方法，可以Mark一下我

方法二：

20191108今天有想出来一个方法，有点繁杂，但也是可以的，用impala-shell

1.先准备一个文件（tables_name.txt），我们会读这个文件

[root@bigdata zw]# more tables_name.txt
show create table cdata.c01_bill_distr_stat
show create table cdata.c01_bill_distr_stat_temp1
show create table cdata.c01_bill_pro_bal
show create table cdata.c01_bill_repay_stat
show create table cdata.c01_bill_repay_stat_temp1

2.一个小脚本

#!/usr/bin/python
# -*- coding:utf-8 -*-

import time,sys
import os
reload(sys)
sys.setdefaultencoding("utf8")

file=open("tables_name.txt")
send_file = file.readlines()
for i in send_file:
   os_cmd1 = "impala-shell -q 'use cdata' "
   os_cmd2 = "impala-shell -q '"+ i.strip('\n') +"'"
   os.system(os_cmd2)
file.close()

都放在一个目录下，运行python脚本，这时候，日志会打印到屏幕上，需要获取屏幕上的日志内容即可。

我用的xshell工具

这个时候，所有的日志都会打印到文件中（bigdata_2019-11-08_17-20-11），可以找到自己想要的内容。

方法三：

#!/usr/bin/env python
#-*- coding:utf8 -*-
# 从mysql中提取hive建表语句
import os,sys
import fileinput
import datetime
import mysql.connector

reload(sys)
sys.setdefaultencoding("utf8")

def hive_create_table():
    conn = mysql.connector.connect(host="192.168.xxx.xxx",user='hive',passwd='',database='hive',charset='utf8')
    mycursor = conn.cursor()
    # 获取DB_ID
    select_DB_ID = "select DB_ID from DBS;"
    mycursor.execute(select_DB_ID)
    result_DB_ID = mycursor.fetchall()
    fo = open("create_tab.sql", "w")
    for dir_DB_ID in result_DB_ID :
        # 获取数据库名
        DB_ID = str(dir_DB_ID)[1:].split(',')[0]
          print(DB_ID)
        select_DB_NAME = "select NAME from DBS where DB_ID="+DB_ID+";"
        print(select_DB_NAME )
        mycursor.execute(select_DB_NAME)
        result_DB_NAME = mycursor.fetchone()
        fo.write("\n===========数据库:"+str(result_DB_NAME).split('\'')[1]+"===========\n")
        DBname=str(result_DB_NAME).split('\'')[1]
        print '数据库名字：' + DBname
        print(result_DB_NAME)
        # 获取表名
        select_table_name_sql = "select TBL_NAME from TBLS where DB_ID="+DB_ID+";"
        mycursor.execute(select_table_name_sql)
        result_table_names = mycursor.fetchall()
        for table_name in result_table_names :
            fo.write("\nCREATE TABLE "+DBname +'.`'+str(table_name).split('\'')[1]+"`(\n")
            # 根据表名获取SD_ID
            select_table_SD_ID = "select SD_ID from TBLS where tbl_name='"+str(table_name).split('\'')[1]+"' and DB_ID="+DB_ID+";"
            print(select_table_SD_ID)
            mycursor.execute(select_table_SD_ID)
            result_SD_ID = mycursor.fetchone()
            print(result_SD_ID )
            # 根据SD_ID获取CD_ID
            SD_ID=str(result_SD_ID)[1:].split(',')[0]
            select_table_CD_ID = "select CD_ID from SDS where SD_ID="+str(result_SD_ID)[1:].split(',')[0]+";"
            print(select_table_CD_ID)
            mycursor.execute(select_table_CD_ID)
            result_CD_ID = mycursor.fetchone()
            print(result_CD_ID)
            # 根据CD_ID获取表的列
            CD_ID=str(result_CD_ID)[1:].split(',')[0]
            select_table_COLUMN_NAME = "select COLUMN_NAME,TYPE_NAME,COMMENT from COLUMNS_V2 where CD_ID="+str(result_CD_ID)[1:].split(',')[0]+" order by INTEGER_IDX;"
            print(select_table_COLUMN_NAME)
            mycursor.execute(select_table_COLUMN_NAME)
            result_COLUMN_NAME = mycursor.fetchall()
            print(result_COLUMN_NAME)
               index=0
            for col,col_type,col_name in result_COLUMN_NAME:
                print(col)
                print(col_type)
                print(col_name)
                print(len(result_COLUMN_NAME) )
            # 写入表的列和列的类型到文件
                if col_name is None:
                   fo.write("  `"+str(col)+"`  "+str(col_type))
                else:
                   fo.write("  `"+str(col)+"`  "+str(col_type) + " COMMENT '" + str(col_name) + "'")
                if index < len(result_COLUMN_NAME)-1:
                   index = index + 1
                   fo.write(",\n")
                elif index == len(result_COLUMN_NAME)-1:
                   fo.write("\n)")
            # 根据表名获取TBL_ID
            select_table_SD_ID = "select TBL_ID from TBLS where tbl_name='"+str(table_name).split('\'')[1]+"' and DB_ID="+DB_ID+";"
            print(select_table_SD_ID)
            mycursor.execute(select_table_SD_ID)
            result_TBL_ID = mycursor.fetchone()
            print(result_TBL_ID)
            # 根据TBL_ID获取分区信息
            select_table_PKEY_NAME_TYPE = "select PKEY_NAME,PKEY_TYPE,PKEY_COMMENT from PARTITION_KEYS where TBL_ID="+str(result_TBL_ID)[1:].split(',')[0]+" order by INTEGER_IDX;"
            print(select_table_PKEY_NAME_TYPE)
            mycursor.execute(select_table_PKEY_NAME_TYPE)
            result_PKEY_NAME_TYPE = mycursor.fetchall()
            print(result_PKEY_NAME_TYPE)
            if len(result_PKEY_NAME_TYPE) > 0:
               fo.write("\nPARTITIONED BY (\n")
            else :
               fo.write("\n")
            i=0
            for pkey_name,pkey_type,PKEY_COMMENT in result_PKEY_NAME_TYPE:
                if str(PKEY_COMMENT) is None:
                   fo.write("  `"+str(pkey_name)+"`  "+str(pkey_type))
                else:
                   fo.write("  `"+str(pkey_name)+"`  "+str(pkey_type) + " COMMENT '" + str(PKEY_COMMENT) + "'\n")
                if i < len(result_PKEY_NAME_TYPE)- 1:
                   i = i + 1
                   fo.write(",")
                elif i == len(result_PKEY_NAME_TYPE) - 1:
                   fo.write(")\n")
            # 根据表TBL_ID 获得中文名称
            select_PARAM_VALUE01 = "select PARAM_VALUE from TABLE_PARAMS  WHERE TBL_ID=( select TBL_ID from TBLS where tbl_name='"+str(table_name).split('\'')[1]+"' and DB_ID="+DB_ID+") and PARAM_KEY='comment';"
            print(select_PARAM_VALUE01)
            mycursor.execute(select_PARAM_VALUE01)
            result_PARAM_VALUE01 = mycursor.fetchone()
            print result_PARAM_VALUE01
            if result_PARAM_VALUE01 is None:
               print '未设置表名'
            elif not result_PARAM_VALUE01[0]:
               print '表名为空'
            else:
               fo.write("COMMENT '" + str(result_PARAM_VALUE01[0]) +"' \n" )
            # 根据SD_ID和CD_ID获取SERDE_ID
            select_SERDE_ID = "select SERDE_ID from SDS where SD_ID="+SD_ID+" and CD_ID="+CD_ID+";"
            print(select_SERDE_ID)
            mycursor.execute(select_SERDE_ID)
            result_SERDE_ID = mycursor.fetchone()
               print(result_SERDE_ID)
            # 根据SERDE_ID获取PARAM_VALUE(列分隔符)
            select_PARAM_VALUE = "select PARAM_VALUE from SERDE_PARAMS where SERDE_ID="+str(result_SERDE_ID)[1:].split(",")[0]+" and PARAM_KEY='field.delim';"
            print(select_PARAM_VALUE)
            mycursor.execute(select_PARAM_VALUE)
            result_PARAM_VALUE = mycursor.fetchone()
            print(result_PARAM_VALUE)
            if result_PARAM_VALUE is not None:
               fo.write("ROW FORMAT DELIMITED\n")
               fo.write("FIELDS TERMINATED BY '"+str(result_PARAM_VALUE).split('\'')[1]+"'\n")
            # 根据SERDE_ID获取PARAM_VALUE(行分隔符)
            select_PARAM_HNAG = "select PARAM_VALUE from SERDE_PARAMS where SERDE_ID="+str(result_SERDE_ID)[1:].split(",")[0]+" and PARAM_KEY='line.delim';"
            print(select_PARAM_HNAG)
            mycursor.execute(select_PARAM_HNAG)
            RESULT_PARAM_HNAG = mycursor.fetchone()
            print(RESULT_PARAM_HNAG)
            if RESULT_PARAM_HNAG is not None:
               fo.write("LINES TERMINATED BY '"+str(RESULT_PARAM_HNAG).split('\'')[1]+"'\n")
            # 根据SD_ID和CD_ID获取输入输出格式
            select_table_STORE_FORMAT = "select INPUT_FORMAT from SDS where SD_ID="+SD_ID+" and CD_ID="+CD_ID+";"
            print(select_table_STORE_FORMAT)
            mycursor.execute(select_table_STORE_FORMAT)
            result_table_STORE_FORMAT= mycursor.fetchall()
            print(result_table_STORE_FORMAT)
            for store_format in result_table_STORE_FORMAT:
                if "org.apache.hadoop.hive.ql.io.orc.OrcInputFormat" in str(store_format):
                   fo.write("STORED AS ORC;\n")
                elif "org.apache.hadoop.mapred.TextInputFormat" in str(store_format):
                   fo.write("STORED AS TEXTFILE;\n")
                elif "org.apache.hadoop.hive.ql.io.parquet.MapredParquetInputFormat" in str(store_format):
                   fo.write("STORED AS PARQUET;\n")
                elif "org.apache.kudu.mapreduce.KuduTableInputFormat" in str(store_format):
                   fo.write("STORED AS KuduTable;\n")
                else :
                   fo.write("STORED AS null;\n")
    fo.close()
hive_create_table()

直接生成建表脚本的SQL文件。可以直接运行建表