Setting schemas in the Map Editor

Talend ESB Studio User Guide

Talend ESB
Design and Development
Talend Studio

In the Map Editor, you can define the type of a table schema as Built-In so that you can modify the data structure in the Schema editor panel, or Repository and retrieve the data structure from the Repository. By default, the schema type is set to Built-In for all tables.

Retrieving the schema structure from the Repository

To retrieve the schema structure of the selected table from the Repository:

  1. Click the tMap Settings button at the top of the table to display the table properties.

  2. Click in the Value field of Schema Type, and then click the three-dot button that appears to open the [Options] dialog box.

  3. In the [Options] dialog box, double-click Repository, or select it and click OK, to close the dialog box and display the Schema Id property beneath Schema Type.


    If you close the Map Editor now without specifying a Repository schema item, the schema type changes back to Built-In.

  4. Click in the Value field of Schema Id, and then click the [...] button that appears to display the [Repository Content] dialog box.

  5. In the [Repository Content] dialog box, select your schema as you define a centrally stored schema for any component, and then click OK.

    The Value field of Schema Id is filled with the schema you just selected, and everything in the Schema editor panel for this table becomes read-only.


    Changing the schema type of the subordinate table across a Join from Built-In to Repository causes the Join to get lost.


    Changes to the schema of a table made in the Map Editor are automatically synchronized to the schema of the corresponding component connected with the tMap component.

Searching schema columns

The schema column filter of tMap allows you to quickly search an input or output schema column or multiple columns among hundreds of them in one go.

The following example shows how to find columns containing the string "customer" in the output table of the Map Editor.

  1. Open the Map Editor, and click the button at the top of the table to open the filter area.

  2. In the filter area, type in your search string, customer in this example.

    As you start to type, the table displays the columns that match the characters.

Using the Schema Editor

The Schema Editor details all fields of the selected table. With the schema type of the table set to Built-In, you can modify the schema of the table.

Use the tool bar below the schema table, to add, move or remove columns from the schema.

You can also load a schema from the repository or export it into a file.




Column name as defined on the Map Editor schemas and on the Input or Output component schemas.


The Key shows if the expression key data should be used to retrieve data through the Join link. If unchecked, the Join relation is disabled.


Type of data: String, Integer, Date, etc.


This column should always be defined in a Java version.


-1 shows that no length value has been defined in the schema.


Defines the number of digits to the right of the decimal point.


Clear this check box if the field value should not be null.


Shows any default value that may be defined for this field.


Free text field. Enter any useful comment.


Input metadata and output metadata are independent from each other. You can, for instance, change the label of a column on the output side without the column label of the input schema being changed.

However, any change made to the metadata are immediately reflected in the corresponding schema on the tMap relevant (Input or Output) area, but also on the schema defined for the component itself on the design workspace.

A Red colored background shows that an invalid character has been entered. Most special characters are prohibited in order for the Job to be able to interpret and use the text entered in the code. Authorized characters include lower-case, upper-case, figures except as start character.