joinTR

joinTR Transformer

Purpose

The purpose of this transformer is to make a join (equivalent of a SQL join) between 2 data sources. It returns only one dataset in output which is the result of this join.

Configuration by using the SQL directly in the configuration file

The specific configuration (as a Datasource) in the configuration file section parameters includes the following parameters:

• join: Join type (can be one of this value : inner, left, right or outer)
• left: Left dataset id and left dataset columns keys (in an sorted array)
• right: Right dataset id and right dataset columns keys (in an sorted array)

Data sources configuration

• Inputs : 2 inputs
• Outputs : 1 output

Configuration example:

    "transformers":  [ { 
        "id": "T1",
        "classname": "pipelite.transformers.joinTR",
        "inputs" : [ "E1", "E2" ],
        "outputs" : [ "L1" ],
        "parameters" : {
            "join" : "inner",
            "left" : { "dsid" : "E1", 
                       "keys" : ["col2"] },
            "right" :  { "dsid" : "E2", 
                          "keys" : ["tcol1"] }
            }
    } ],
    ... ] ...