sqoop 中文文檔 User guide 六

16.sqoop-create-hive-table

16.1.Purpose

Thecreate-hive-tabletool populates a Hive metastore with a definition for a table based on a database table previously imported to HDFS, or one planned to be imported. This effectively performs the "--hive-import" step ofsqoop-importwithout running the preceeding import.

在create-hive-table工具填充一個元存儲通過定義一個表基於一個以前已經導入到HDFS的數據庫表，或一個計劃被導入。”--hive-import ”是sqoop-import其中的一步，不需要先執行導入。

（create-hive-table 的用途 1 在hive定義一個表名關聯到已經導入到HDFS中的表 2 在 hive中創建一個表，這個表可以用於以後的導入）

If data was already loaded to HDFS, you can use this tool to finish the pipeline of importing the data to Hive. You can also create Hive tables with this tool; data then can be imported and populated into the targetafter a preprocessing step run by the user.

如果數據已經加載到HDFS,您可以使用此工具來完成導入數據到hive的管道（關聯導入的數據到hive）。您還可以使用此工具創建hive表;然後數據可以導入並填充到目標在用戶運行一個預處理步驟後。

16.2.Syntax

$ sqoop create-hive-table (generic-args) (create-hive-table-args)
$ sqoop-create-hive-table (generic-args) (create-hive-table-args)

Although the Hadoop generic arguments must preceed any create-hive-table arguments, the create-hive-table arguments can be entered in any order with respect to one another（這個句子翻譯好多次了）.

Table34.Common arguments

Argument	Description
--connect <jdbc-uri>	Specify JDBC connect string
--connection-manager <class-name>	Specify connection manager class to use
--driver <class-name>	Manually specify JDBC driver class to use
--hadoop-mapred-home <dir>	Override $HADOOP_MAPRED_HOME
--help	Print usage instructions
-P	Read password from console
--password <password>	Set authentication password
--username <username>	Set authentication username
--verbose	Print more information while working
--connection-param-file <filename>	Optional properties file that provides connection parameters

Table35.Hive arguments:

Argument	Description
--hive-home <dir>	Override$HIVE_HOME
--hive-overwrite	Overwrite existing data in the Hive table.
--create-hive-table	If set, then the job will fail if the target hive
	table exits. By default this property is false.
--hive-table <table-name>	Sets the table name to use when importing to Hive.
--table	The database table to read the definition from.

Table36.Output line formatting arguments:

Argument	Description
--enclosed-by <char>	Sets a required field enclosing character
--escaped-by <char>	Sets the escape character
--fields-terminated-by <char>	Sets the field separator character
--lines-terminated-by <char>	Sets the end-of-line character
--mysql-delimiters	Uses MySQL’s default delimiter set: fields:,lines:\nescaped-by:\optionally-enclosed-by:'
--optionally-enclosed-by <char>	Sets a field enclosing character

Do not use enclosed-by or escaped-by delimiters with output formatting arguments used to import to Hive. Hive cannot currently parse them.

16.3.Example Invocations

Define in Hive a table namedempswith a definition based on a database table namedemployees:

定義在一個名叫emps蜂巢表與一個基於數據庫表定義一個名爲員工

在hive中定義名爲emps的表 通過一個名爲employees的數據庫表的定義（建表需要表結構）：

$ sqoop create-hive-table --connect jdbc:mysql://db.example.com/corp \
    --table employees --hive-table emps

sqoop-eval :返回sql 查詢結果，可以檢驗查詢結果是否符自己的預期

17.sqoop-eval

17.1.Purpose

Theevaltool allows users to quickly run simple SQL queries against a database; results are printed to the console. This allows users to preview their import queries to ensure they import the data they expect.

eval工具允許用戶快速運行簡單的SQL查詢數據庫;結果打印到控制檯。這允許用戶預覽他們的導入查詢以確保他們導入數據他們期望

17.2.Syntax

$ sqoop eval (generic-args) (eval-args)
$ sqoop-eval (generic-args) (eval-args)

Although the Hadoop generic arguments must preceed any eval arguments, the eval arguments can be entered in any order with respect to one another.

Table37.Common arguments

Argument	Description
--connect <jdbc-uri>	Specify JDBC connect string
--connection-manager <class-name>	Specify connection manager class to use
--driver <class-name>	Manually specify JDBC driver class to use
--hadoop-mapred-home <dir>	Override $HADOOP_MAPRED_HOME
--help	Print usage instructions
-P	Read password from console
--password <password>	Set authentication password
--username <username>	Set authentication username
--verbose	Print more information while working
--connection-param-file <filename>	Optional properties file that provides connection parameters

Table38.SQL evaluation arguments:

Argument	Description
-e,--query <statement>	Executestatementin SQL.

17.3.Example Invocations

Select ten records from theemployeestable:

從employees表中查詢10條記錄

$ sqoop eval --connect jdbc:mysql://db.example.com/corp \
    --query "SELECT * FROM employees LIMIT 10"

Insert a row into thefootable:

插入一行到foo表：

$ sqoop eval --connect jdbc:mysql://db.example.com/corp \
    -e "INSERT INTO foo VALUES(42, 'bar')"

18.sqoop-list-databases

18.1.Purpose

List databaseschemaspresent on a server.

列出所有數據庫名：

18.2.Syntax

$ sqoop list-databases (generic-args) (list-databases-args)
$ sqoop-list-databases (generic-args) (list-databases-args)

Although the Hadoop generic arguments must preceed any list-databases arguments, the list-databases arguments can be entered in any order with respect to one another.

Table39.Common arguments

Argument	Description
--connect <jdbc-uri>	Specify JDBC connect string
--connection-manager <class-name>	Specify connection manager class to use
--driver <class-name>	Manually specify JDBC driver class to use
--hadoop-mapred-home <dir>	Override $HADOOP_MAPRED_HOME
--help	Print usage instructions
-P	Read password from console
--password <password>	Set authentication password
--username <username>	Set authentication username
--verbose	Print more information while working
--connection-param-file <filename>	Optional properties file that provides connection parameters

18.3.Example Invocations

List database schemas available on a MySQL server:

列出MySQL服務器上可用的數據庫的名:

$ sqoop list-databases --connect jdbc:mysql://database.example.com/
information_schema
employees

	Note
	This only works with HSQLDB, MySQL and Oracle. When using with Oracle, it is necessary that the user connecting to the database has DBA privileges.

19.sqoop-list-tables

19.1.Purpose

List tables present in a database.

出現在一個數據庫

19.2.Syntax

$ sqoop list-tables (generic-args) (list-tables-args)
$ sqoop-list-tables (generic-args) (list-tables-args)

Although the Hadoop generic arguments must preceed any list-tables arguments, the list-tables arguments can be entered in any order with respect to one another.

Table40.Common arguments

Argument	Description
--connect <jdbc-uri>	Specify JDBC connect string
--connection-manager <class-name>	Specify connection manager class to use
--driver <class-name>	Manually specify JDBC driver class to use
--hadoop-mapred-home <dir>	Override $HADOOP_MAPRED_HOME
--help	Print usage instructions
-P	Read password from console
--password <password>	Set authentication password
--username <username>	Set authentication username
--verbose	Print more information while working
--connection-param-file <filename>	Optional properties file that provides connection parameters

19.3.Example Invocations

List tables available in the "corp" database:

列出corp數據庫中所有有效的表：

$ sqoop list-tables --connect jdbc:mysql://database.example.com/corp
employees
payroll_checks
job_descriptions
office_supplies

In case of postgresql, list tables command with common arguments fetches only "public" schema. For custom schema, use --schema argument to list tables of particular schema Example

如果是postgresql數據庫,表列表命令只在“公共”模式下好用。對於自定義模式,使用  --schema來列出表名

$ sqoop list-tables --connect jdbc:postgresql://localhost/corp  --username name -P -- --schema payrolldept
employees
expenses

20.sqoop-help

20.1.Purpose

List tools available in Sqoop and explain their usage.

列出在sqoop中有效的工具並解釋它們的用法

20.2.Syntax

$ sqoop help [tool-name]
$ sqoop-help [tool-name]

If no tool name is provided (for example, the user runssqoop help), then the available tools are listed. With a tool name, the usage instructions for that specific tool are presented on the console.

如果沒有工具的名字被提供(例如,用戶運行 sqoop help),這時 所有可用的工具都列出。指定一個工具名稱（如：sqoop help import ）,這個工具的使用說明顯示在控制檯。

20.3.Example Invocations

List available tools:

列出所有有效的工具：

$ sqoop help
usage: 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

...

See 'sqoop help COMMAND' for information on a specific command.

Display usage instructions for theimporttool:

顯示導入工具的使用說明：

$ bin/sqoop help import
usage: sqoop import [GENERIC-ARGS] [TOOL-ARGS]

Common arguments:
   --connect <jdbc-uri>     Specify JDBC connect string
   --connection-manager <class-name>     Specify connection manager class to use
   --driver <class-name>    Manually specify JDBC driver class to use
   --hadoop-mapred-home <dir>            Override $HADOOP_MAPRED_HOME
   --help                   Print usage instructions
-P                          Read password from console
   --password <password>    Set authentication password
   --username <username>    Set authentication username
   --verbose                Print more information while working
   --hadoop-home <dir>      Deprecated. Override $HADOOP_HOME

Import control arguments:
   --as-avrodatafile             Imports data to Avro Data Files
   --as-sequencefile             Imports data to SequenceFiles
   --as-textfile                 Imports data as plain text (default)
...

21.sqoop-version

21.1.Purpose

Display version information for Sqoop.

顯示sqoop版本信息

21.2.Syntax

$ sqoop version
$ sqoop-version

21.3.Example Invocations

Display the version:

顯示 版本：

$ sqoop version
Sqoop {revnumber}
git commit id 46b3e06b79a8411320d77c984c3030db47dd1c22
Compiled by aaron@jargon on Mon May 17 13:43:22 PDT 2010