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SQL and ETL with Kettle
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SQL and ETL with Kettle

MediumSQL · PostgreSQL

Problem

What are common SQL and transformation tasks you handle with Kettle (job and transformations)?

Use the supplied PostgreSQL tables to demonstrate a representative transformation that joins related data, filters records, calculates order totals, aggregates customer results, handles missing values, and assigns a classification.

Output

  1. Return one row per customer with customer_id, customer_name, completed_orders, total_sales, average_order_value, and sales_band.
  2. Include customers without completed orders, order by total_sales descending and customer_id ascending.

Schema

customers
ColumnTypeDescription
customer_idPKINTUnique customer identifier
customer_nameVARCHAR(100)Customer display name
orders
ColumnTypeDescription
order_idPKINTUnique order identifier
customer_idINTCustomer associated with the order
order_dateDATEDate the order was created
statusVARCHAR(20)Order processing status
order_items
ColumnTypeDescription
order_item_idPKINTUnique order line identifier
order_idINTOrder containing the item
product_nameVARCHAR(100)Name of the purchased product
quantityINTNumber of units ordered
unit_priceNUMERIC(10,2)Price per unit
Tablescustomersordersorder_items
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