We suppose that you have already learned what is described in:

If you want to find the appropriate Transformer for your purpose, see Transformers Comparison.

Short Summary

MetaPivot converts every incoming record into several output records, each one representing a single field from the input.

Abstract

On its single input port, MetaPivot receives data that do not have to be sorted. Each field of the input record is written as a new line on the output. The metadata represent data types and are restricted to a fixed format, see Advanced Description All in all, MetaPivot can be used to effectively transform your records to a neat data-dependent structure.

Unlike Normalizer, which MetaPivot is derived from, no transofmation is defined. MetaPivot always does the same tranformation: it takes the input records and "rotates them" thus turning input columns to output rows.

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Ports

MetaPivot Attributes

MetaPivot has no component-specific attributes.

Advanced Description

	Important
	When working with MetaPivot, you have to use a fixed format of the output metadata. The metadata fields represent particular data types. Field names and data types have to be set exactly as follows (otherwise unexpected BadDataFormatException will occur):

[recordNo long] - the serial number of a record (outputs can be later grouped by this) - fields of the same record share the same number (notice in Figure 47.7, Example MetaPivot Output )

[fieldNo integer] - the current field number: 0...n-1 where n is the number of fields in the input metadata

[fieldName string] - name of the field as it appeared on the input

[fieldType string] - the field type, e.g. "string", "date", "decimal"

[valueBoolean boolean] - the boolean value of the field

[valueByte byte] - the byte value of the field

[valueDate date] - the date value of the field

[valueDecimal decimal] - the decimal value of the field

[valueInteger integer] - the integer value of the field

[valueLong long] - the long value of the field

[valueNumber number] - the number value of the field

[valueString string] - the string value of the field

The total number of output records produced by MetaPivot equals to (number of input records) * (number of input fields).

You may have noticed some of the fields only make the output look better arranged. That is true - if you needed to omit them for whatever reasons, you can do it. The only three fields that do not have to be included in the output metadata are: recordNo, fieldNo and fieldType.

Example 47.4. Example MetaPivot Transformation

Let us now look at what MetaPivot makes to your data. Say you have a delimited file containing data of various data types. You have only two records:

Figure 47.6. Example MetaPivot Input

Sending these data to MetaPivot "classifies" the data to output fields corresponding to their data types:

Figure 47.7. Example MetaPivot Output

Thus e.g. "hello" is placed in the valueString field or "76.70" in valueDecimal. Since there were 2 records and 9 fields on the input, we have got 18 records on the output.