An ALTER TABLE ADD COLUMN migration is run twice (non-idempotent migration). A CREATE TABLE statement has the same column name listed twice. Automated schema generation tools produce duplicate column definitions

Step 1: Check if the column already exists: `SELECT COUNT(*) FROM information_schema.columns WHERE table_schema='your_db' AND table_name='your_table' AND column_name='your_col';`. Step 2: Skip the ALTER if the column already exists — wrap in a stored procedure with conditional logic.. Step 3: Use a versioned migration tool (Flyway or Liquibase) that tracks applied migrations and prevents duplicate runs.

Medium severityschema

Power BI Refresh Error:
1060

What does this error mean?

A CREATE TABLE or ALTER TABLE statement tries to add a column that already exists in the table.

Common causes

1An ALTER TABLE ADD COLUMN migration is run twice (non-idempotent migration)
2A CREATE TABLE statement has the same column name listed twice
3Automated schema generation tools produce duplicate column definitions

How to fix it

1Step 1: Check if the column already exists: `SELECT COUNT(*) FROM information_schema.columns WHERE table_schema='your_db' AND table_name='your_table' AND column_name='your_col';`
2Step 2: Skip the ALTER if the column already exists — wrap in a stored procedure with conditional logic.
3Step 3: Use a versioned migration tool (Flyway or Liquibase) that tracks applied migrations and prevents duplicate runs.

Frequently asked questions

Does MySQL 8.0 support ALTER TABLE ADD COLUMN IF NOT EXISTS?

No — MySQL does not natively support IF NOT EXISTS for ADD COLUMN. Use a stored procedure or application-level logic to check column existence before altering.

How can I make schema migrations idempotent in MySQL?

Check information_schema.columns before each ADD COLUMN, use versioned migration tools like Flyway or Liquibase, and never run raw migration scripts manually.

Can MetricSign monitor migration-related pipeline failures?

Yes — MetricSign tracks ADF and dbt job failures, surfacing the MySQL error code to help diagnose whether a pipeline failure is caused by a schema migration issue.

Official documentation: https://dev.mysql.com/doc/mysql-errors/8.0/en/server-error-reference.html