Component family |
Processing/Fields |
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Function |
tWriteJSONField transforms the If you have subscribed to one of the Talend solutions with Big Data, you are |
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Purpose |
tWriteJSONField transforms the |
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Basic settings |
Output Column |
List of the columns defined in the output schema to hold the JSON |
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Configure JSON Tree |
Opens the interface to create the JSON data structure. For more |
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Schema and Edit |
A schema is a row description, it defines the number of fields to Since version 5.6, both the Built-In mode and the Repository mode are Click Edit schema to make changes to the schema. If the
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Built-in: You create the schema |
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Repository: The schema already |
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Sync columns |
Click to synchronize the output file schema with the input file |
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Group by |
Define the aggregation set, the columns you want to use to regroup WarningMake sure that the data to be grouped is in sequential |
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Remove root node |
Select this check box to remove the root node from the JSON field |
Advanced settings
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tStatCatcher Statistics |
Select this check box to gather the Job processing metadata at a |
Global Variables |
ERROR_MESSAGE: the error message generated by the NB_LINE: the number of rows read by an input component or A Flow variable functions during the execution of a component while an After variable To fill up a field or expression with a variable, press Ctrl + For further information about variables, see Talend Studio |
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Usage |
Preceded by an input component, this component wraps the incoming |
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Usage in Map/Reduce Jobs |
If you have subscribed to one of the Talend solutions with Big Data, you can also You need to use the Hadoop Configuration tab in the For further information about a Talend Map/Reduce Job, see the sections Note that in this documentation, unless otherwise explicitly stated, a scenario presents |
When configuring a JSON tree, the default type of an element is string. If an
element is not of type string, you need to add an
attribute for the element to set its type.
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For an integer, double, float, or
boolean element, you need to add an
attribute named type and set its static
value to integer, number, float, or boolean respectively. -
For an array element, you need to add
an attribute named class and set its static
value to array, and then add a sub-element
named element set as a loop. -
For an object element, you need to add
an attribute named class and set its static
value to object.
The following figure shows an example of JSON tree configuration:
In this scenario, flat data is wrapped into JSON fields via tWriteJSONField.
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Drop the following components from the Palette onto the design workspace: tFixedFlowInput, tWriteJSONField and tLogRow.
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Link tFixedFlowInput and tWriteJSONField using a Row > Main connection.
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Link tWriteJSONField and tLogRow using a Row > Main connection.
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Double-click tFixedFlowInput to display
its Basic settings view. -
Click Edit schema to open the schema
editor.Click the [+] button to add three
columns, namely firstname, lastname and dept, with the type of string.Click OK to close the editor.
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Select the Use Inline Content option and
enter the data below in the Content box:123Andrew;Wallace;DocJohn;Smith;R&DChristian;Dior;Sales -
Click tWriteJSONField to display its
Basic settings view.Select the Remove root node option to
remove the root node setting from the JSON fields generated. -
Click Configure JSON Tree to open the XML
tree editor.The schema of tFixedFlowInput appears in
the Linker source panel. -
In the Linker target panel, click the
default rootTag and type in staff, which is the root node of the JSON field
to be generated. -
Right-click staff and select Add Sub-element from the context menu.
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In the pop-up box, enter the sub-node name, namely firstname.
Repeat the steps to add two more sub-nodes, namely lastname and dept.
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Right-click firstname and select
Set As Loop Element from the context
menu. -
Drop firstname from the Linker source panel to its counterpart in the
Linker target panel.In the pop-up dialog box, select Add linker to
target node.Click OK to close the dialog box.
Repeat the steps to link the two other items.
Click OK to close the XML tree
editor. -
Click Edit schema to open the schema
editor. -
Click the [+] button in the right panel
to add one column, namely staff, which
will hold the JSON data generated.Click OK to close the editor.
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Double-click tLogRow to display its
Basic settings view.Select Table (print values in cells of a
table) for a better display of the results.
For related scenarios, see: