How can I check that column on a delta table has a "NOT NULL" constraint or not?

Lon_Fortes
Databricks Partner

‎08-18-2021 08:30 AM

Title pretty much says it all -

I'm trying to determine whether or not a column on my existing delta table was defined as NOT NULL or not. It does not show up in any of the metadata (describe detail, describe history, show tblproperties).

Thanks in advance

Lon_Fortes
Databricks Partner

‎08-18-2021 09:38 AM

I've found a solution, the following scala serves my needs:

val table = spark.table("<database>.<tablename>")

val schema = table.printSchema

View solution in original post

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Matthew8
New Contributor II

‎08-19-2021 12:19 AM

walgreenslistens Wrote:

A UNIQUE constraint defines a set of columns that uniquely identify rows in a table only if all the key values are not NULL. If one or more key parts are NULL, duplicate keys are allowed.

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muki
New Contributor II

‎01-07-2026 02:42 PM

if using python, we can use

display(spark.catalog.listColumns('<catalog>.<schema>.<table>'))
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iyashk-DB
Databricks Employee
Databricks Employee

‎01-08-2026 12:11 AM

@muki , you can run 
SHOW CREATE TABLE <catalog>.<schema>.<table>

and in that also you can also see the constraints applied.