July 30, 2023

tELTTeradataMap – Docs for ESB 7.x

tELTTeradataMap

Builds the SQL SELECT statement using the table schema(s) provided by one or more
tELTTeradataInput components.

The three ELT Teradata components are closely related,
in terms of their operating conditions. These components should be used to handle
Teradata database table schemas to generate SQL statements, including clauses, which are
to be executed in the database output table defined.

tELTTeradataMap Standard properties

These properties are used to configure tELTTeradataMap running in the Standard Job framework.

The Standard
tELTTeradataMap component belongs to the ELT family.

The component in this framework is available in all Talend
products
.

Basic settings

Use an existing connection

Select this check box and in the Component List click the relevant connection component to
reuse the connection details you already defined.

Note: When a Job contains the parent Job and the child Job, if you
need to share an existing connection between the two levels, for example, to share the
connection created by the parent Job with the child Job, you have to:

  1. In the parent level, register the database connection
    to be shared in the Basic
    settings
    view of the connection component which creates that very database
    connection.

  2. In the child level, use a dedicated connection
    component to read that registered database connection.

For an example about how to share a database connection
across Job levels, see

Talend Studio
User Guide
.

ELT Teradata Map editor

The ELT Map editor allows you to define the output schema as well as
build graphically the SQL statement to be executed. The column names of
schema can be different from the column names in the database.

Style link

Select the way in which links are displayed.

Auto: By default, the links between the
input and output schemas and the Web service parameters are in the form
of curves.

Bezier curve: Links between the schema
and the Web service parameters are in the form of curve.

Line: Links between the schema and the
Web service parameters are in the form of straight lines.

This option slightly optimizes performance.

Property type

Either Built-in or Repository.

 

Built-in: No property data stored
centrally.

 

Repository: Select the Repository
file where Properties are stored. The following fields are pre-filled in
using fetched data.

Host

Database server IP address

Database

Name of the database

Username and Password

DB user authentication data.

To enter the password, click the […] button next to the
password field, and then in the pop-up dialog box enter the password between double quotes
and click OK to save the settings.

Advanced settings

Query band

Select this check box to use the Teradata Query Banding feature to add metadata to the query
to be processed, such as the user running the query. This can help you, for example,
identify the origin of this query.

Once selecting the check box, the Query Band parameters
table is displayed, in which you need to enter the metadata information to be added. This
information takes the form of key/value pairs, for example, DpID in the Key column and Finance in the Value
column.

This check box actually generates the SET QUERY_BAND FOR SESSION statement with the key/value
pairs declared in the Query Band parameters table. For
further information about this statement, see https://docs.teradata.com/search/all?query=End+logging+syntax.

This check box is not available when you have selected the Using an
existing connection
check box. In this situation, if you need to use the
Query Band feature, set it in the Advanced settings tab of
the Teradata connection component to be used.

tStatCatcher Statistics

Select this check box to collect log data at the component
level.

Global Variables

Global Variables

ERROR_MESSAGE: the error message generated by the
component when an error occurs. This is an After variable and it returns a string. This
variable functions only if the Die on error check box is
cleared, if the component has this check box.

A Flow variable functions during the execution of a component while an After variable
functions after the execution of the component.

To fill up a field or expression with a variable, press Ctrl +
Space
to access the variable list and choose the variable to use from it.

For further information about variables, see
Talend Studio

User Guide.

Usage

Usage rule

tELTTeradataMap is used along with a
tELTTeradataInput and tELTTeradataOutput. Note that the Output link
to be used with these components must faithfully reflect the name of the
tables.

Note:

The ELT components do not handle actual data flow but only schema
information.

Dynamic settings

Click the [+] button to add a row in the table
and fill the Code field with a context
variable to choose your database connection dynamically from multiple
connections planned in your Job. This feature is useful when you need to
access database tables having the same data structure but in different
databases, especially when you are working in an environment where you
cannot change your Job settings, for example, when your Job has to be
deployed and executed independent of Talend Studio.

The Dynamic settings table is
available only when the Use an existing
connection
check box is selected in the Basic settings view. Once a dynamic parameter is
defined, the Component List box in the
Basic settings view becomes unusable.

For examples on using dynamic parameters, see Reading data from databases through context-based dynamic connections and Reading data from different MySQL databases using dynamically loaded connection parameters. For more information on Dynamic
settings
and context variables, see Talend Studio
User Guide.

Mapping data using a subquery

The sample Job described in this scenario maps the data from two input tables,
PreferredSubject and CourseScore, to the
output table, TotalScoreOfPreferredSubject, using a
subquery.

Prerequisite

Ensure that you have added an Oracle database connection in the Metadata > Db Connections section prior to creating the Job. For more information, see the
Centralizing database metadata section of the Talend Data Integration Studio User
Guide
.

The Standard Job and the Prejob design

In this scenario, design the Standard Job such as the following:

tELTTeradataMap_1.png
Design the Prejob that includes the data in this scenario as follows:

tELTTeradataMap_2.png
The PreferredSubject table contains the student’s
preferred subject data. To reproduce this scenario, you can load the following data to
the Oracle table from a CSV
file:
The CourseScore table contains the student’s
subject score data. To reproduce this scenario, you can load the following data to the
Oracle table from a CSV
file:
Before the Job execution, the output table
TotalScoreOfPreferredSubject does not contain any
data:

Creating the Prejob

Create the
Prejob that contains the data that you wish to load to the Oracle table.

See the Prejob design image in The Standard Job and the Prejob design
section.

  1. Create a
    Standard Job.
  2. Add the following components:

    • Prejob
    • two tFixedFlowInput components
    • two tOracleOutput components
    • two tOracleInput components
    • one tCreateTable component
    • two tLogRow components
  3. Configure the first tFixedFlowInput component:

    1. Select the tFixedFlowInput component to display
      the Basic settings view.
    2. Select Use Inline Content(delimited file) from
      the Mode options.
    3. Add the following data to the Content
      field:

    4. Click next to the Edit
      Schema
      field to open the Schema
      Editor
      .
    5. Add four columns with the following names and corresponding
      parameters:

      tELTTeradataMap_3.png
  4. Configure the second tFixedFlowInput component:

    1. Repeat steps 3a and 3b.
    2. Add the following data to the Content
      field:

    3. Click next to the Edit
      Schema
      field to open the Schema
      Editor
      .
    4. Add six columns with the following names and corresponding
      parameters:

      tELTTeradataMap_4.png
  5. Select the first tOracleOutput component to open the
    Basic settings view.

    1. Select Repository from the Property
      Type
      drop-down list.
    2. Specify the Oracle database connection the you have previously added by
      clicking . This automatically populates the
      database information in the fields provided.
    Repeat step 6 and steps 6a-6b to configure the second
    tOracleOutput component.
  6. Select the tCreateTable component to open the
    Basic settings view.

    1. Select Oracle from the Database
      Type
      drop-down list.
    2. Select Repository from the Property
      Type
      drop-down list.
    3. Specify the Oracle database connection that you have previously added
      by clicking . This automatically populates the
      database information in the fields provided.
    4. Enter TotalScoreOfPreferredSubject in the
      Table Name field.
    5. Select Drop table if exists and create from the
      Table Action drop-down list.
    6. Click next to the Edit
      schema
      field to open the Schema
      editor
      .
    7. Add four columns with the following corresponding names and
      parameters:

      tELTTeradataMap_5.png

Adding the components

  1. Add the following components by typing their names in the design
    workspace or dropping them from the Palette:

    • twotELTOracleInput components
    • two tELTOracleMap components
    • one tELTOracleOutput component
    • one tOracleInput
      component
    • one tLogRow component
  2. Rename the tELTOracleMap
    components to SubqueryMap and ELTMap.

Configuring the input components

  1. Select the first tELTOracleInput component to display the Basic settings tab.
  2. Enter "PreferredSubject" in
    the Default Table Name field.
  3. Click […] next to Edit
    schema
    to define the schema of the input table PreferredSubject in the schema editor.
  4. Click [+] to
    add four columns:

    • SeqID with the DB Type
      set to INTEGER
    • StuName, Subject, and Detail with the DB Type set to VARCHAR
    tELTTeradataMap_6.png

    Click OK to validate these
    changes and close the schema editor.
  5. Connect the first tELTOracleInput component to the second tELTOracleMap component using the Link > PreferredSubject(Table).
  6. Select the second tELTOracleInput component to display the Basic settings tab.
  7. Enter "CourseScore" in the
    Default Table Name field.
  8. Click […] next to Edit
    schema
    to define the schema of the input table CourseScore in the schema editor.
  9. Click the [+] button to add six columns:

    • SeqID and Score with the DB Type set to INTEGER
    • StuName, Subject, Course, and Detail with
      the DB Type set to VARCHAR
    tELTTeradataMap_7.png

    Click OK to validate these changes and close the schema editor.
  10. Connect the second tELTOracleInput component to the first
    tELTOracleMap
    component using the Link > CourseScore(Table).

Configuring the output component

  1. Select the tELTOracleOutput component to display the
    Basic settings view.

    tELTTeradataMap_8.png

  2. Enter "TotalScore
    OfPreferredSubject"
    in the Default Table
    Name
    field.
  3. Click […] next to Edit
    schema
    to define the schema of the output table in the schema
    editor.
  4. Click [+] to
    add four columns:

    • SeqID and TotalScore with the DB Type set to INTEGER
    • StuName and PreferredSubject with the DB Type set to
      VARCHAR
    tELTTeradataMap_9.png

    Click OK to validate these changes and close the schema editor.
  5. Click Sync columns to
    sychronize the Input and Output tables of the
    tELTOracleOutput
    component.

    tELTTeradataMap_10.png

Configuring data mapping to generate a subquery

  1. Click the SubqueryMap component (next to the second tELTOracleInput) to open
    its Basic settings view.

    Note: Specify the Oracle database connection information in the second
    ELTMap component in the Job.

  2. Click […] next to ELT Oracle
    Map Editor
    to open its map editor.

    tELTTeradataMap_11.png

  3. Add the input table CourseScore by clicking [+] in the upper left corner of the map editor and then selecting the
    relevant table name from the drop-down list in the pop-up dialog box.
  4. Add an output table by clicking [+] in the upper right corner of the
    map editor and then entering the table name TotalScore in the corresponding field in the pop-up dialog box.
  5. Drag StuName, Subject, and Score columns in the input table and then drop them to
    the output table.
  6. Click the Add filter row button in the upper right corner of the
    output table and select Add an
    other(GROUP…) clause
    from the pop-up menu. Then in the Additional other clauses (GROUP/ORDER
    BY…)
    field displayed, enter the clause GROUP BY CourseScore.StuName, CourseScore.Subject.

    Add the aggregate function SUM for the column
    Score of the output table by changing the
    expression of this column to SUM(CourseScore.Score).
  7. Click the Generated SQL Select query for ‘table1’ output tab at
    the bottom of the map editor to display the corresponding generated SQL
    statement.

    tELTTeradataMap_12.png

    This SQL query will appear as a subquery in the
    SQL query generated by the ELTMap
    component.
  8. Click OK to validate these changes and close
    the map editor.
  9. Connect the first SubqueryMap to ELTMap using
    the Link > TotalScore (table1) link. Note that the link is renamed automatically to TotalScore (Table_ref) since the
    output table TotalScore is a reference
    table.

Mapping the input and output schemas

  1. Right-click ELTMap and select Link > *New Output* (Table) from the contextual menu.
  2. Click TotalScoreOfPreferredSubject. In the pop-up dialog box, click
    Yes to get the schema
    from the target component.
  3. Click ELTMap to open its Basic settings view.
  4. Select Repository from
    the Property Type drop-down list. Specify the Oracle database you previously
    added to automatically propagate the database connection information.

    tELTTeradataMap_13.png

  5. Click […] next to ELT Oracle Map Editor to open its map
    editor.
  6. Add the input table PreferredSubject by clicking the [+] button in the upper left corner of the map
    editor and selecting the relevant table name from the drop-down list in the
    pop-up dialog box.

    Repeat the step to add another input table
    TotalScore.
  7. Drag the StuName column in the input table
    PreferredSubject
    and drop it to the corresponding column in the
    input table TotalScore. Then select the
    Explicit join check
    box for the StuName column in the input
    table TotalScore.

    Repeat the step for the Subject column.
  8. Drag the SeqID column in the input table PreferredSubject and drop it to the corresponding column in the
    output table.

    Repeat the step to drag the StuName and Subject columns in the input table PreferredSubject and the Score column in the input table TotalScore and drop them to the corresponding column in the
    output table.
  9. Click the Generated SQL Select query for “table2” output
    tab at the bottom of the map editor to display the corresponding generated SQL
    statement.

    tELTTeradataMap_14.png

    The SQL query generated in the SubqueryMap component appears as a subquery in
    the SQL query generated by this component. Alias will be automatically added for
    the selected columns in the subquery.
  10. Click OK to validate these changes and close the map
    editor.

Executing the Job

Click Run to
execute the Job.

tELTTeradataMap_15.png

The select statement is generated and the mapping
data are written into the output table.


Document get from Talend https://help.talend.com
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