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From: Thomas White <tomwhite@apache.org> git-svn-id: https://svn.apache.org/repos/asf/incubator/sqoop/trunk@1149843 13f79535-47bb-0310-9956-ffa450edef68
59 lines
2.4 KiB
Plaintext
59 lines
2.4 KiB
Plaintext
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////
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Licensed to the Apache Software Foundation (ASF) under one or more
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contributor license agreements. See the NOTICE file distributed with
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this work for additional information regarding copyright ownership.
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The ASF licenses this file to You under the Apache License, Version 2.0
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(the "License"); you may not use this file except in compliance with
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the License. You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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////
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Exporting to a Database
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-----------------------
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In addition to importing database tables into HDFS, Sqoop can also
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work in "reverse," reading the contents of a file or directory in
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HDFS, interpreting the data as database rows, and inserting them
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into a specified database table.
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To run an export, invoke Sqoop with the +--export-dir+ and
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+--table+ options. e.g.:
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----
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$ sqoop --connect jdbc:mysql://db.example.com/foo --table bar \
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--export-dir /results/bar_data
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----
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This will take the files in +/results/bar_data+ and inject their
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contents in to the +bar+ table in the +foo+ database on +db.example.com+.
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The target table must already exist in the database. Sqoop will perform
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a set of +INSERT INTO+ operations, without regard for existing content. If
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Sqoop attempts to insert rows which violate constraints in the database
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(e.g., a particular primary key value already exists), then the export
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will fail.
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As in import mode, Sqoop will auto-generate an interoperability class
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to use with the particular table in question. This will be used to parse
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the records in HDFS files before loading their contents into the database.
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You must specify the same delimiters (e.g., with +--fields-terminated-by+,
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etc.) as are used in the files to export in order to parse the data
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correctly. If your data is stored in SequenceFiles (created with an import
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in the +--as-sequencefile+ format), then you do not need to specify
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delimiters.
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If you have an existing auto-generated jar and class that you intend to use
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with Sqoop, you can specify these with the +--jar-file+ and +--class-name+
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parameters. Providing these options will disable autogeneration of a new
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class based on the target table.
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