Oracle Database Error:
ORA-01401

What does this error mean?

A value being inserted is longer than the column's defined length (VARCHAR2, CHAR, or NVARCHAR2).

Common causes

• 1Source string is longer than the Oracle column definition allows
• 2Column was shortened in Oracle but the pipeline was not updated
• 3Unicode data stored as NVARCHAR2 has a byte-length limit that exceeds the character count
• 4Free-text fields in the source have grown beyond the expected max length

How to fix it

1. 1Step 1: Check the column definition: `SELECT column_name, data_type, data_length FROM all_tab_columns WHERE table_name = '<TABLE>';`.
2. 2Step 2: Truncate the source value in the pipeline: `SUBSTR(source_col, 1, <max_length>)`.
3. 3Step 3: Widen the column if truncation is not acceptable: `ALTER TABLE t MODIFY column_name VARCHAR2(500);`.
4. 4Step 4: Add a data quality check upstream to flag values that exceed the target column length.
5. 5Step 5: Use Oracle's `TRUNC` on character columns if business rules allow silently trimming.

Example log output

ORA-01401: inserted value too large for column
SQL: INSERT INTO customers (name) VALUES (:1)  -- value was 520 chars, column is VARCHAR2(256)

Frequently asked questions

Other data errors