本文主要是介绍获取impala下所有的数据库建表语句，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
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 ===========" >> $database.sqlecho "$(hive -e "use $database;show create table $table;");" >> $database.sqldone 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.connectorreload(sys)
sys.setdefaultencoding("utf8")def hive_create_table():conn = mysql.connector.connect(host="192.168.xxx.xxx",user='hive',passwd='123456',database='hive',charset='utf8')mycursor = conn.cursor()# 获取DB_IDselect_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：' + DBnameprint(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_IDselect_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_IDSD_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=0for 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 + 1fo.write(",\n")elif index == len(result_COLUMN_NAME)-1:fo.write("\n)")# 根据表名获取TBL_IDselect_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=0for 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 + 1fo.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_VALUE01if 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_IDselect_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
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