Knime Database nodes.

KNIME Analytics Platform
1

Hi,

We have been using database nodes for working on data present in MySQL database.

I would like to know if we can perform the below listed operations on the data :

1.How to run data manipulation queries in Database Query node
2.How to change the name of a column through Database query

3.Cross join in KNIME through sql / Database nodes

4.How are missing values treated in Database node

There are some posts in the forum which suggest to use column rename node and write the data to database but we would like to directly execute these queries on the database using SQL nodes.

Any ideas and suggestions will be highly appreciated.

Thanks in advance.

 

 

2

Hi,

  1. KNIME provides several data manipulation nodes such as writer, update, drop table and sql executor
  2. You can use the SQL AS command in the database query node to rename a column
  3. You have to create a dummy column with a constant value that you use as join column
  4. Missing values are represented as NULL in the database.

Please find attached a KNIME workflow that demonstrates all the above mentioned operations using the integrated SQLite DB operator. You can find additional example workflows in the KNIME Examples server in the 004_Databases category.

Bye,

Tobias

3

Thanka a lot Tobias.

The attached workflow helped a lot.