Writing schema files

The code example takes the example. The code example also provides a ValidationEventHandler as a parameter to the static Read method to handle any schema validation warnings or errors encountered while reading the XML schema.

If the ValidationEventHandler is not specified null , no warnings or errors are reported. Skip to main content. From the above example, printSchema prints the schema to console stdout and show displays the content of the Spark DataFrame. While working on Spark DataFrame we often need to work with the nested struct columns. On the below example I am using a different approach to instantiating StructType and use add method instead of StructField to add column names and datatype. Prints below schema and DataFrame.

Note that printSchema displays struct for nested structure fields. Note the definition in JSON uses the different layout and you can get this by using schema. This prints the same output as the previous section.

You can also, have a name, type, and flag for nullable in a comma-separated file and we can use these to create a struct programmatically, I will leave this to you to explore. After its execution, the example application generates the following output:. Example of Writing a Flat File The following example application contains:. A Scheduler component that triggers the flow A File Read operation that reads a file containing the JSON output from the previous example A Transform Message component that transforms the JSON payload to the specified flat file format A Logger component that outputs the current payload A File Write operation that outputs the payload to a flat file in the specified target path.

Amount, "Type": tdr. Type, "Unique File Identifier": payload. This element can appear multiple times inside a "shiporder" element. This is specified by setting the maxOccurs attribute of the "item" element to "unbounded" which means that there can be as many occurrences of the "item" element as the author wishes. Notice that the "note" element is optional. We have specified this by setting the minOccurs attribute to zero:. We can now declare the attribute of the "shiporder" element.

The previous design method is very simple, but can be difficult to read and maintain when documents are complex. The next design method is based on defining all elements and attributes first, and then referring to them using the ref attribute.

The third design method defines classes or types, that enables us to reuse element definitions. This is done by naming the simpleTypes and complexTypes elements, and then point to them through the type attribute of the element.

So, the following fragment means that the value of the element or attribute must be a string value:.