Encountering unexpected error codes while working with Microsoft SQL Server can be frustrating, especially when the message is cryptic or doesn’t immediately hint at the root cause. One such error is SQL Server Error Code 1060. While not the most common SQL Server error, when it appears, it can bring a project to a halt until it’s properly addressed. Fortunately, with the right troubleshooting steps and a basic understanding of the cause, resolving error 1060 is usually quite straightforward.
In this article, we will explore what SQL Server Error 1060 means, delve into the common causes behind it, and walk through a detailed, step-by-step guide to help you fix it effectively. We’ll also share tips to help prevent reoccurrence and maintain a healthier database environment.
What is SQL Server Error Code 1060?
SQL Server Error 1060 is generally associated with a duplicate column name in a table. This error typically surfaces during table alterations, complex scripting, or when trying to add a column that already exists. The full error message might appear as:
“Column names in each table must be unique. Column name ‘column_name’ in table ‘table_name’ is specified more than once.”
This means SQL Server has detected an attempt to define more than one column with the same name in a table definition. Since column names must be unique within a single table, SQL Server throws error 1060 to prevent the change or operation.
Common Scenarios Where Error 1060 Occurs
There are several situations in which this error may appear. Understanding how and when the error occurs can help guide your troubleshooting process:
- During the execution of a CREATE TABLE or ALTER TABLE statement where a column is being added redundantly.
- When importing schema or structure data—especially from a script—into an existing database.
- In cases of code generation tools or ORM (Object Relational Mapper) frameworks producing overlapping column names in generated SQL.
- If you accidentally repeat a column definition in a complex script with lengthy CREATE or ALTER operations.
Step-by-Step Guide to Fix SQL Server Error Code 1060
Step 1: Review the Error Message and Query
Carefully read the error message provided by SQL Server. It often indicates which table and column are causing the issue. For instance:
Msg 1060, Level 16, State 1, Line 1
Column names in each table must be unique. Column name ‘Email’ in table ‘Customer’ is specified more than once.
This immediately tells you that your current operation is attempting to define the column Email more than once in the Customer table. Your first action is to open the SQL script or command that triggered this error.
Step 2: Check Table Definition
To confirm existing columns in a table and avoid duplications, use the following query:
SELECT COLUMN_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'Customer';This will provide a list of all current column names in the Customer table. If the name cited in the error message already exists here, it confirms the root of the issue.
Step 3: Remove or Rename Duplicate Column Definition
If the duplication is indeed the cause, you have two options:
- Remove the duplicate: Edit your SQL script so the column in question isn’t defined more than once.
- Rename the column: If you genuinely need two different columns, ensure they have unique names. For example, if you accidentally tried to add two “Email” columns, renaming one to something more descriptive like “WorkEmail” or “AlternateEmail” can solve the issue.
Here’s a corrected version of an ALTER TABLE statement that would avoid the error:
ALTER TABLE Customer
ADD AlternateEmail VARCHAR(255);Step 4: Verify Changes with Tools
If you’re using SQL Server Management Studio (SSMS), use the table designer tool to visually confirm changes. This eliminates the risk of typing errors and allows you to see all column names at a glance.
Navigate to:
- SSMS > Object Explorer > Your Database > Tables > Right-click the table > Design
This opens a grid-based editor where you can easily verify column names, data types, and constraints. Make sure no duplicate column names appear here and save your changes if modifications were made.
Step 5: Re-run the Script or Operation
After correcting the column conflict in the table definition, run your query or script again. If the only issue was the duplicate column name, the error should no longer occur. However, be alert for cascading errors if the offending column name was referenced elsewhere in dependent scripts or stored procedures.
Prevention Tips: How to Avoid Error Code 1060 in the Future
Prevention is always better than cure. Here are a few best practices that can reduce the chances of encountering SQL Server Error 1060:
- Use script templates wisely: When copying and modifying scripts, ensure column names are updated and not accidentally duplicated.
- Adopt naming conventions: Use naming policies that make column names descriptive and unique across tables.
- Automate column checks: Before executing
ALTERorCREATEscripts, useINFORMATION_SCHEMAqueries to check for existing columns. - Validate generated SQL scripts: If using tools like Entity Framework or Hibernate, always inspect the SQL they generate before executing them in production environments.
- Use version control: If working in a team, track changes to table structures in a source control system so duplicates can be easily traced and resolved.
Final Thoughts
SQL Server Error Code 1060 is a clear indicator that there’s a naming conflict in your table column definitions. Although it can be annoying to run into, the fix is typically simple once you’ve identified the duplicate. By following the step-by-step guide outlined in this article, you’ll be well-equipped to troubleshoot and resolve the error efficiently.
More importantly, adopting a preventive approach, like applying standardized naming conventions, using SQL validation tools, and maintaining proper documentation, will help you avoid this error altogether in future projects.
Stay alert and organized in your database management strategy, and SQL Server will be a powerful ally—not a source of mystery messages that slow you down!