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简介：
本篇文章主要介绍sqoop的基本语法及简单使用方法。[hadoop@hadoop000 ~]$ sqoop helpusage: sqoop COMMAND [ARGS]Available commands: codegen Generate code to interact with database records create-hive-table Import a table definition into Hive eval Evaluate a SQL statement and display the results export Export an HDFS directory to a database table help List available commands import Import a table from a database to HDFS import-all-tables Import tables from a database to HDFS import-mainframe Import datasets from a mainframe server to HDFS job Work with saved jobs list-databases List available databases on a server list-tables List available tables in a database merge Merge results of incremental imports metastore Run a standalone Sqoop metastore version Display version informationSee 'sqoop help COMMAND' for information on a specific command.# 这里提示我们使用sqoop help command（要查询的命令）进行该命令的详细查询
# 查看list-databases命令帮助[hadoop@hadoop000 ~]$ sqoop help list-databasesusage: sqoop list-databases [GENERIC-ARGS] [TOOL-ARGS]Common arguments: --connectSpecify JDBC connect string --connection-manager Specify connection manager class name --connection-param-file Specify connection parameters file --driver Manually specify JDBC driver class to use --hadoop-home Override $HADOOP_MAPRED_HOME_ARG --hadoop-mapred-home Override $HADOOP_MAPRED_HOME_ARG --help Print usage instructions-P Read password from console --password Set authentication password --password-alias Credential provider password alias --password-file Set authentication password file path --relaxed-isolation Use read-uncommitted isolation for imports --skip-dist-cache Skip copying jars to distributed cache --username Set authentication username --verbose Print more information while working# 简单使用[hadoop@oradb3 ~]$ sqoop list-databases \> --connect jdbc:mysql://localhost:3306 \> --username root \> --password 123456# 结果information_schemamysqlperformance_schemaslow_query_logsystest
# 命令帮助[hadoop@hadoop000 ~]$ sqoop help list-tablesusage: sqoop list-tables [GENERIC-ARGS] [TOOL-ARGS]Common arguments: --connectSpecify JDBC connect string --connection-manager Specify connection manager class name --connection-param-file Specify connection parameters file --driver Manually specify JDBC driver class to use --hadoop-home Override $HADOOP_MAPRED_HOME_ARG --hadoop-mapred-home Override $HADOOP_MAPRED_HOME_ARG --help Print usage instructions-P Read password from console --password Set authentication password --password-alias Credential provider password alias --password-file Set authentication password file path --relaxed-isolation Use read-uncommitted isolation for imports --skip-dist-cache Skip copying jars to distributed cache --username Set authentication username --verbose Print more information while working# 使用方法[hadoop@hadoop000 ~]$ sqoop list-tables \> --connect jdbc:mysql://localhost:3306/test \> --username root \> --password 123456# 结果t_ordertest0001test_1013test_dyctest_tb
(默认导入当前用户目录下/user/用户名/表名)
说到这里扩展一个小知识点：# 查看命令帮助[hadoop@hadoop000 ~]$ sqoop help import# 执行import[hadoop@hadoop000 ~]$ sqoop import \> --connect jdbc:mysql://localhost:3306/test \> --username root \> --password 123456 \> --table students
这时很可能会出现这个错误
Exception in thread "main" java.lang.NoClassDefFoundError: org/json/JSONObject这里我们需要导入java-json.jar包 把java-json.jar添加到../sqoop/lib目录下即可 # 再次执行 import导入[hadoop@hadoop000 ~]$ sqoop import \> --connect jdbc:mysql://localhost:3306/test \> --username root \> --password 123456 \> --table students18/07/04 13:28:35 INFO sqoop.Sqoop: Running Sqoop version: 1.4.6-cdh5.7.018/07/04 13:28:35 WARN tool.BaseSqoopTool: Setting your password on the command-line is insecure. Consider using -P instead.18/07/04 13:28:35 INFO manager.MySQLManager: Preparing to use a MySQL streaming resultset.18/07/04 13:28:35 INFO tool.CodeGenTool: Beginning code generation18/07/04 13:28:35 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `students` AS t LIMIT 118/07/04 13:28:35 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `students` AS t LIMIT 118/07/04 13:28:35 INFO orm.CompilationManager: HADOOP_MAPRED_HOME is /home/hadoop/app/hadoop-2.6.0-cdh5.7.018/07/04 13:28:37 INFO orm.CompilationManager: Writing jar file: /tmp/sqoop-hadoop/compile/3024b8df04f623e8c79ed9b5b30ace75/students.jar18/07/04 13:28:37 WARN manager.MySQLManager: It looks like you are importing from mysql.18/07/04 13:28:37 WARN manager.MySQLManager: This transfer can be faster! Use the --direct18/07/04 13:28:37 WARN manager.MySQLManager: option to exercise a MySQL-specific fast path.18/07/04 13:28:37 INFO manager.MySQLManager: Setting zero DATETIME behavior to convertToNull (mysql)18/07/04 13:28:37 INFO mapreduce.ImportJobBase: Beginning import of students18/07/04 13:28:38 INFO Configuration.deprecation: mapred.jar is deprecated. Instead, use mapreduce.job.jar18/07/04 13:28:39 INFO Configuration.deprecation: mapred.map.tasks is deprecated. Instead, use mapreduce.job.maps18/07/04 13:28:39 INFO client.RMProxy: Connecting to ResourceManager at /0.0.0.0:803218/07/04 13:28:41 INFO db.DBInputFormat: Using read commited transaction isolation18/07/04 13:28:41 INFO db.DataDrivenDBInputFormat: BoundingValsQuery: SELECT MIN(`id`), MAX(`id`) FROM `students`18/07/04 13:28:41 INFO db.IntegerSplitter: Split size: 0; Num splits: 4 from: 1001 to: 100318/07/04 13:28:41 INFO mapreduce.JobSubmitter: number of splits:318/07/04 13:28:42 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1530598609758_001518/07/04 13:28:42 INFO impl.YarnClientImpl: Submitted application application_1530598609758_001518/07/04 13:28:42 INFO mapreduce.Job: The url to track the job: http://oradb3:8088/proxy/application_1530598609758_0015/18/07/04 13:28:42 INFO mapreduce.Job: Running job: job_1530598609758_001518/07/04 13:28:52 INFO mapreduce.Job: Job job_1530598609758_0015 running in uber mode : false18/07/04 13:28:52 INFO mapreduce.Job: map 0% reduce 0%18/07/04 13:28:58 INFO mapreduce.Job: map 33% reduce 0%18/07/04 13:28:59 INFO mapreduce.Job: map 67% reduce 0%18/07/04 13:29:00 INFO mapreduce.Job: map 100% reduce 0%18/07/04 13:29:00 INFO mapreduce.Job: Job job_1530598609758_0015 completed successfully18/07/04 13:29:00 INFO mapreduce.Job: Counters: 30...18/07/04 13:29:00 INFO mapreduce.ImportJobBase: Transferred 40 bytes in 21.3156 seconds (1.8766 bytes/sec)18/07/04 13:29:00 INFO mapreduce.ImportJobBase: Retrieved 3 records.# 生成的日志信息大家一定要好好理解# 查看HDFS上的文件[hadoop@hadoop000 ~]$ hadoop fs -ls /user/hadoop/studentsFound 4 items-rw-r--r-- 1 hadoop supergroup 0 2018-07-04 13:28 /user/hadoop/students/_SUCCESS-rw-r--r-- 1 hadoop supergroup 13 2018-07-04 13:28 /user/hadoop/students/part-m-00000-rw-r--r-- 1 hadoop supergroup 13 2018-07-04 13:28 /user/hadoop/students/part-m-00001-rw-r--r-- 1 hadoop supergroup 14 2018-07-04 13:28 /user/hadoop/students/part-m-00002[hadoop@hadoop000 ~]$ hadoop fs -cat /user/hadoop/students/"part*"1001,lodd,231002,sdfs,211003,sdfsa,24
我们还可以加一些其他参数 使导入过程更加可控
-m指定启动map进程个数，默认是4个--delete-target-dir删除目标目录--mapreduce-job-name指定mapreduce的job的名字--target-dir导入到指定目录--fields-terminated-by指定字段之间的分隔符--null-string含义是 string类型的字段，当Value是NULL，替换成指定的字符--null-non-string含义是非string类型的字段，当Value是NULL，替换成指定字符--columns导入表中的部分字段--where按条件导入数据--query按照sql语句进行导入 使用--query关键字，就不能使用--table和--columns--options-file在文件中执行
# 执行导入[hadoop@hadoop000 ~]$ sqoop import \> --connect jdbc:mysql://localhost:3306/test \> --username root --password 123456 \> --mapreduce-job-name FromMySQL2HDFS \> --delete-target-dir \> --table students \> -m 1# HDFS中查看[hadoop@hadoop000 ~]$ hadoop fs -ls /user/hadoop/students Found 2 items-rw-r--r-- 1 hadoop supergroup 0 2018-07-04 13:53 /user/hadoop/students/_SUCCESS-rw-r--r-- 1 hadoop supergroup 40 2018-07-04 13:53 /user/hadoop/students/part-m-00000[hadoop@oradb3 ~]$ hadoop fs -cat /user/hadoop/students/"part*"1001,lodd,231002,sdfs,211003,sdfsa,24
# 使用where 参数[hadoop@hadoop000 ~]$ sqoop import \> --connect jdbc:mysql://localhost:3306/test \> --username root --password 123456 \> --table students \> --mapreduce-job-name FromMySQL2HDFS2 \> --delete-target-dir \> --fields-terminated-by '\t' \> -m 1 \> --null-string 0 \> --columns "name" \> --target-dir STU_COLUMN_WHERE \> --where 'id<1002'# HDFS 结果[hadoop@hadoop000 ~]$ hadoop fs -cat STU_COLUMN_WHERE/"part*"lodd
# 使用query 参数[hadoop@hadoop000 ~]$ sqoop import \> --connect jdbc:mysql://localhost:3306/test \> --username root --password 123456 \> --mapreduce-job-name FromMySQL2HDFS3 \> --delete-target-dir \> --fields-terminated-by '\t' \> -m 1 \> --null-string 0 \> --target-dir STU_COLUMN_QUERY \> --query "select * from students where id>1001 and \$CONDITIONS"# HDFS查看[hadoop@hadoop000 ~]$ hadoop fs -cat STU_COLUMN_QUERY/"part*"1002 sdfs 211003 sdfsa 24
# 使用options-file参数[hadoop@hadoop000 ~]$ vi sqoop-import-hdfs.txtimport--connectjdbc:mysql://localhost:3306/test--usernameroot--password123456--tablestudents--target-dirSTU_option_file# 执行导入[hadoop@hadoop000 ~]$ sqoop --options-file /home/hadoop/sqoop-import-hdfs.txt# HDFS查看[hadoop@hadoop000 ~]$ hadoop fs -cat STU_option_file/"part*"1001,lodd,231002,sdfs,211003,sdfsa,24
查看帮助命令对与该命令的解释为： Evaluate a SQL statement and display the results，也就是说执行一个SQL语句并查询出结果。
# 查看命令帮助[hadoop@hadoop000 ~]$ sqoop help evalusage: sqoop eval [GENERIC-ARGS] [TOOL-ARGS]Common arguments: --connectSpecify JDBC connect string --connection-manager Specify connection manager class name --connection-param-file Specify connection parameters file --driver Manually specify JDBC driver class to use --hadoop-home Override $HADOOP_MAPRED_HOME_ARG --hadoop-mapred-home Override $HADOOP_MAPRED_HOME_ARG --help Print usage instructions-P Read password from console --password Set authentication password --password-alias Credential provider password alias --password-file Set authentication password file path --relaxed-isolation Use read-uncommitted isolation for imports --skip-dist-cache Skip copying jars to distributed cache --username Set authentication username --verbose Print more information while workingSQL evaluation arguments:-e,--query Execute 'statement' in SQL and exit# 执行[hadoop@hadoop000 ~]$ sqoop eval \> --connect jdbc:mysql://localhost:3306/test \> --username root --password 123456 \> --query "select * from students"18/07/04 14:28:44 INFO sqoop.Sqoop: Running Sqoop version: 1.4.6-cdh5.7.018/07/04 14:28:44 WARN tool.BaseSqoopTool: Setting your password on the command-line is insecure. Consider using -P instead.18/07/04 14:28:44 INFO manager.MySQLManager: Preparing to use a MySQL streaming resultset.----------------------------------------------------| id | name | age | ----------------------------------------------------| 1001 | lodd | 23 | | 1002 | sdfs | 21 | | 1003 | sdfsa | 24 | ----------------------------------------------------
常用参数：
--table指定导出表的名称--input-fields-terminated-by指定hdfs上文件的分隔符，默认是逗号--export-dir导出数据的目录--columns指定导出的字段
在执行导出语句前mysql要先创建表（不创建表会报错）：
# HDFS原文件[hadoop@hadoop000 ~]$ hadoop fs -cat /user/hadoop/students/part-m-000001001,lodd,231002,sdfs,211003,sdfsa,24# export导出到mysql[hadoop@hadoop000 ~]$ sqoop export \> --connect jdbc:mysql://localhost:3306/test \> --username root \> --password 123456 \> --table students_demo \> --export-dir /user/hadoop/students/18/07/04 14:46:20 INFO sqoop.Sqoop: Running Sqoop version: 1.4.6-cdh5.7.018/07/04 14:46:20 WARN tool.BaseSqoopTool: Setting your password on the command-line is insecure. Consider using -P instead.18/07/04 14:46:20 INFO manager.MySQLManager: Preparing to use a MySQL streaming resultset.18/07/04 14:46:20 INFO tool.CodeGenTool: Beginning code generation18/07/04 14:46:21 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `students_demo` AS t LIMIT 118/07/04 14:46:21 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `students_demo` AS t LIMIT 118/07/04 14:46:21 INFO orm.CompilationManager: HADOOP_MAPRED_HOME is /home/hadoop/app/hadoop-2.6.0-cdh5.7.018/07/04 14:46:24 INFO orm.CompilationManager: Writing jar file: /tmp/sqoop-hadoop/compile/fc7b53dd6eef701c0731c7a7c4a4b340/students_demo.jar18/07/04 14:46:24 INFO mapreduce.ExportJobBase: Beginning export of students_demo18/07/04 14:46:25 INFO Configuration.deprecation: mapred.jar is deprecated. Instead, use mapreduce.job.jar18/07/04 14:46:25 INFO Configuration.deprecation: mapred.map.max.attempts is deprecated. Instead, use mapreduce.map.maxattempts18/07/04 14:46:26 INFO Configuration.deprecation: mapred.reduce.tasks.speculative.execution is deprecated. Instead, use mapreduce.reduce.speculative18/07/04 14:46:26 INFO Configuration.deprecation: mapred.map.tasks.speculative.execution is deprecated. Instead, use mapreduce.map.speculative18/07/04 14:46:26 INFO Configuration.deprecation: mapred.map.tasks is deprecated. Instead, use mapreduce.job.maps...18/07/04 14:46:55 INFO mapreduce.ExportJobBase: Transferred 672 bytes in 29.3122 seconds (22.9256 bytes/sec)18/07/04 14:46:55 INFO mapreduce.ExportJobBase: Exported 3 records.# mysql中查看mysql> select * from students_demo;+------+-------+------+| id | name | age |+------+-------+------+| 1001 | lodd | 23 || 1002 | sdfs | 21 || 1003 | sdfsa | 24 |+------+-------+------+3 rows in set (0.00 sec)
如果再导入一次会追加在表中
# 增加columns参数[hadoop@hadoop000 ~]$ sqoop export \> --connect jdbc:mysql://localhost:3306/test \> --username root \> --password 123456 \> --table students_demo2 \> --export-dir /user/hadoop/students/ \> --columns id,name# mysql结果mysql> select * from students_demo2;+------+-------+------+| id | name | age |+------+-------+------+| 1001 | lodd | NULL || 1002 | sdfs | NULL || 1003 | sdfsa | NULL |+------+-------+------+3 rows in set (0.00 sec)
常用参数：
--create-hive-table创建目标表，如果有会报错--hive-database指定hive数据库--hive-import指定导入hive（没有这个条件导入到hdfs中）--hive-overwrite覆盖--hive-table指定hive中表的名字，如果不指定使用导入的表的表名--hive-partition-key指定Hive分区表字段--hive-partition-value指定导入的分区值
首次导入可能会报错如下：
18/07/04 15:06:26 ERROR hive.HiveConfig: Could not load org.apache.hadoop.hive.conf.HiveConf. Make sure HIVE_CONF_DIR is set correctly.<br/>18/07/04 15:06:26 ERROR tool.ImportTool: Encountered IOException running import job: java.io.IOException: java.lang.ClassNotFoundException: org.apache.hadoop.hive.conf.HiveConf解决方法：到hive目录的lib下拷贝几个jar包，问题就解决了 # 报错解决方法[hadoop@hadoop000 lib]$ pwd/home/hadoop/app/hive-1.1.0-cdh5.7.0/lib[hadoop@hadoop000 lib]$ cp hive-common-1.1.0-cdh5.7.0.jar /home/hadoop/app/sqoop-1.4.6-cdh5.7.0/lib/[hadoop@hadoop000 lib]$ cp hive-shims* /home/hadoop/app/sqoop-1.4.6-cdh5.7.0/lib/
# 报错解决后执行导入[hadoop@hadoop000 ~]$ sqoop import \> --connect jdbc:mysql://localhost:3306/test \> --username root --password 123456 \> --table students \> --create-hive-table \> --hive-database hive \> --hive-import \> --hive-overwrite \> --hive-table stu_import \> --mapreduce-job-name FromMySQL2HIVE \> --delete-target-dir \> --fields-terminated-by '\t' \> -m 1 \> --null-non-string 0# Hive中查看hive> show tables;OKstu_importTime taken: 0.051 seconds, Fetched: 1 row(s)hive> select * from stu_import;OK1001 lodd 231002 sdfs 211003 sdfsa 24Time taken: 0.969 seconds, Fetched: 3 row(s)
建议：导入Hive不建议大家使用–create-hive-table参数,建议事先创建好hive表；因为自动创建的表字段类型可能并不是我们想要的。
# 增加partition参数[hadoop@hadoop000 ~]$ sqoop import \> --connect jdbc:mysql://localhost:3306/test \> --username root --password 123456 \> --table students \> --create-hive-table \> --hive-database hive \> --hive-import \> --hive-overwrite \> --hive-table stu_import2 \> --mapreduce-job-name FromMySQL2HIVE2 \> --delete-target-dir \> --fields-terminated-by '\t' \> -m 1 \> --null-non-string 0 \> --hive-partition-key dt \> --hive-partition-value "2018-08-08"# Hive中查看hive> select * from stu_import2;OK1001 lodd 23 2018-08-081002 sdfs 21 2018-08-081003 sdfsa 24 2018-08-08Time taken: 0.192 seconds, Fetched: 3 row(s)
sqoop job可以将执行的语句变成一个job，并不是在创建语句的时候执行，你可以查看该job，可以任何时候执行该job，也可以删除job，这样就方便我们进行任务的调度。
--create<job-id> 创建一个新的job.--delete<job-id> 删除job--exec<job-id> 执行job--show<job-id> 显示job的参数--list列出所有的job
# 创建job[hadoop@hadoop000 ~]$ sqoop job --create person_job1 -- import --connect jdbc:mysql://localhost:3306/test \> --username root \> --password 123456 \> --table students_demo \> -m 1 \> --delete-target-dir# 查看job[hadoop@hadoop000 ~]$ sqoop job --listAvailable jobs: person_job1# 执行job 会提示输入mysql root用户密码[hadoop@hadoop000 ~]$ sqoop job --exec person_job1# HDFS查看[hadoop@hadoop000 lib]$ hadoop fs -ls /user/hadoop/students_demoFound 2 items-rw-r--r-- 1 hadoop supergroup 0 2018-07-04 15:34 /user/hadoop/students_demo/_SUCCESS-rw-r--r-- 1 hadoop supergroup 40 2018-07-04 15:34 /user/hadoop/students_demo/part-m-00000
我们发现执行person_job的时候，需要输入数据库的密码，怎么样能不输入密码呢
配置sqoop-site.xml即可解决# 将sqoop.metastore.client.record.password参数的注释去掉 或者再添加一下[hadoop@hadoop000 conf]$ pwd/home/hadoop/app/sqoop-1.4.6-cdh5.7.0/conf[hadoop@hadoop000 conf]$ vi sqoop-site.xmlsqoop.metastore.client.record.password true If true, allow saved passwords in the metastore.
参考文章：
转载于:https://blog.51cto.com/10814168/2136156