ORA01400

ORA01400 is an Oracle Database error message that indicates a constraint violation. Specifically, it occurs when an attempt is made to insert a NULL value into a column that is defined as NOT NULL. This error is commonly encountered in database operations where data integrity is enforced through constraints.

The error message typically appears as follows:

ORA-01400: cannot insert NULL into ("OWNER"."TABLE_NAME"."COLUMN_NAME")

To resolve this issue, the following steps can be taken:

1. Ensure that the application or script inserting data into the table provides a value for the column that is defined as NOT NULL.

2. Modify the table schema to allow NULL values in the column if it is appropriate for the application's logic.

3. Check the data being inserted to ensure that all required fields are populated.

Understanding and addressing ORA01400 requires a careful examination of the database schema, the data being inserted, and the application logic to ensure data integrity and compliance with database constraints.