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kettle控件addachecksum

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This step calculates checksums for one or more fields in the input stream and adds this to the output as a new field. 为数据流输入的列计算校验码，并将输出作为新的一列。 wiki中介绍：http://wiki.pentaho.com/display/EAI/Add+a+checksum Option

This step calculates checksums for one or more fields in the input stream and adds this to the output as a new field.

为数据流输入的列计算校验码，并将输出作为新的一列。

wiki中介绍：http://wiki.pentaho.com/display/EAI/Add+a+checksum

Option

Description

Step name

Name of the step. Note: This name has to be unique in a single transformation.

Type

The type of checksum that needs to be calculated. These are the types that are available:

  • CRC32 : 32-bit Cyclic Redundancy Check : http://en.wikipedia.org/wiki/Cyclic_redundancy_check
  • ADLER 32 : Checksum algorithm by Mark Adler: http://en.wikipedia.org/wiki/Adler-32
  • MD5 : Message Digest algorithm 5 : http://en.wikipedia.org/wiki/MD5
  • SHA-1 : Secure Hash Algorithm 1 : http://en.wikipedia.org/wiki/SHA-1
    		•

    Result field

    The name of the result field containing the checksum

    Fields used in the checksum

    The names of the fields to include in the checksum calculation.
    Note: You can use the "Get Fields" button to insert all input fields from previous steps.

    注意，双击控件后，可以看到各种设置项。result field为新列的名称，一定要写。

    这时候看到compatibility mode选项，打钩后，字段就会变得紧凑，不定长。默认为不选，是32位长的字段！

    我为了比较字段，所以用定长。

    如果想知道区别，做测试：


    然后就preview rows，就可以看出两种结果的不同
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