The following scenario creates a Job that opens a connection to a Mysql database
and:

• instantiates the schemas from a database table whose rows match the column
  names specified in the filter,

• filters a column in the same database table to have only the data that matches
  a WHERE clause,

• collects data grouped by specific value(s) from the filtered column and writes
  aggregated data in a target database table.

To filter and aggregate database table columns:

• Drop the following components from the Palette onto the design workspace: tELTMysqlconnection, tSQLTemplateFilterColumns, tSQLTemplateFilterRows, tSQLTemplateAggregate, tSQLTemplateCommit, and tSQLTemplateRollback.

• Connect the five first components using OnComponentOk
  links.

• Connect tSQLTemplateAggregate to tSQLTemplateRollback using an OnComponentError link.

• In the design workspace, select tMysqlConnection and click the Component tab to define the basic settings for tMysqlConnection.

• In the Basic settings view, set the database
  connection details manually or select Repository from the Property
  Type list and select your DB connection if it has already been
  defined and stored in the Metadata area of the
  Repository tree view.

For more information about Metadata, see
Talend Studio User
Guide.

• In the design workspace, select tSQLTemplateFilterColumns and click the Component tab to define its basic settings.

• On the Database type list, select the
  relevant database.

• On the Component list, select the relevant
  database connection component if more than one connection is used.

• Enter the names for the database, source table, and target table in the
  corresponding fields and click the three-dot buttons next to Edit schema to define the data structure in the
  source and target tables.

In this scenario, the source table has five columns: id, First_Name,
Last_Name, Address, and id_State.

• In the Column filters panel, set the column
  filter by selecting the check boxes of the columns you want to write in the
  source table.

In this scenario, the tSQLTemplateFilterColumns
component instantiates only three columns: id, First_Name,
and id_State from the source table.

• In the design workspace, select tSQLTemplateFilterRows and click the Component tab to define its basic settings.

• On the Database type list, select the
  relevant database.

• On the Component list, select the relevant
  database connection component if more than one connection is used.

• Enter the names for the database, source table, and target table in the
  corresponding fields and click the three-dot buttons next to Edit schema to define the data structure in the
  source and target tables.

In this scenario, the source table has the three initially instantiated columns:
id, First_Name, and id_State and the
source table has the same three-column schema.

• In the Where condition field, enter a WHERE
  clause to extract only those records that fulfill the specified
  criterion.

In this scenario, the tSQLTemplateFilterRows
component filters the First_Name column in the source
table to extract only the first names that contain the “a” letter.

• In the design workspace, select tSQLTemplateAggregate and click the Component tab to define its basic settings.

• On the Database type list, select the
  relevant database.

• On the Component list, select the relevant
  database connection component if more than one connection is used.

• Enter the names for the database, source table, and target table in the
  corresponding fields and click the three-dot buttons next to Edit schema to define the data structure in the
  source and target tables.

The schema for the source table consists of the three columns: id,
First_Name, and id_State. The schema for the target
table consists of two columns: customers_status and
customers_number. In this scenario, we want to group customers
by their marital status and count customer number in each marital group. To do that, we
define the Operations and Group
by panels accordingly.

• In the Operations panel, click the plus
  button to add one or more lines and then click in the Output column line to select the output column that will hold
  the counted data.

• Click in the Function line and select the
  operation to be carried on.

• In the Group by panel, click the plus button
  to add one or more lines and then click in the Output
  column line to select the output column that will hold the
  aggregated data.

• In the design workspace, select tSQLTemplateCommit and click the Component tab to define its basic settings.

• On the Database type list, select the
  relevant database.

• On the Component list, select the relevant
  database connection component if more than one connection is used.

• Do the same for tSQLTemplateRollback.

• Save your Job and press F6 to execute
  it.

A two-column table aggregate_customers is created in the
database. It groups customers according to their marital status and count customer
number in each marital group.