How to fix Error 468 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: SQL Server Error 468 – Collation Conflict

Why This Error Happens

Error 468 occurs when SQL Server attempts to compare, concatenate, or join text data (char, varchar, nvarchar, etc.) from two sources that have been assigned different collations, and the engine cannot automatically determine which collation rule set should take precedence. This typically happens when a database or column was explicitly created with a non-default collation (e.g., during a migration or restore from a different regional server) while tempdb or another joined table retains the server’s default collation (e.g., SQL_Latin1_General_CP1_CI_AS vs. Latin1_General_100_CI_AS_SC). Since SQL Server 2025 enforces strict collation matching for comparison operators (=, LIKE, JOIN predicates) and UNION operations, the query fails rather than risking incorrect character sorting or comparison results.

Step-by-Step Resolution Guide

Step 1: Identify the Conflicting Collations

  • Run the following query to check the collation of the specific columns involved in the failing query: SELECT name, collation_name FROM sys.columns WHERE object_id = OBJECT_ID('YourTableName');
  • Check the server-level default collation using: SELECT SERVERPROPERTY('Collation');
  • Check the database-level collation using: SELECT name, collation_name FROM sys.databases WHERE name = 'YourDatabaseName';
  • Note the exact discrepancy (e.g., one is _CI_AS case-insensitive and the other is _CS_AS case-sensitive).

Step 2: Apply a Query-Level Collation Fix (Quick Patch)

  • For immediate resolution without altering the schema, use the COLLATE keyword directly in your T-SQL query to force both sides of the comparison to match.
  • Example syntax: SELECT * FROM TableA a JOIN TableB b ON a.ColumnX COLLATE DATABASE_DEFAULT = b.ColumnY COLLATE DATABASE_DEFAULT;
  • Alternatively, force a specific collation: WHERE a.ColumnX COLLATE Latin1_General_100_CI_AS = b.ColumnY;
  • This step is ideal for ad-hoc reporting queries or stored procedures where you cannot alter the underlying table schema.

Step 3: Alter the Column Collation Permanently (Schema Fix)

  • If the conflict persists across multiple queries, permanently change the column’s collation to match your organization’s standard.
  • Navigate to SQL Server Management Studio (SSMS) 21 (compatible with SQL Server 2025) and open a New Query window.
  • Execute the alteration command: ALTER TABLE YourTableName ALTER COLUMN ColumnX VARCHAR(100) COLLATE SQL_Latin1_General_CP1_CI_AS;
  • Ensure no indexes are currently active on that specific column, as ALTER COLUMN will fail if the column is part of an index; you may need to drop and recreate the index post-alteration.

Step 4: Rebuild TempDB Collation (If System-Wide)

  • If the conflict specifically involves temporary tables (#TempTable) versus permanent tables, the issue lies in tempdb‘s collation differing from the user database.
  • Open SQL Server Configuration Manager on Windows Server 2025, stop the SQL Server service.
  • Restart the instance via Command Prompt using the startup parameter to rebuild master/tempdb with the new collation: sqlservr.exe -m -T4022 -s"MSSQLSERVER" /q"Latin1_General_100_CI_AS"
  • Restart the SQL Server service normally via the Services console (services.msc).

Alternative or Verification Steps

  • Verify the Fix: Re-run the original query that triggered Error 468. If successful, execute SELECT DATABASEPROPERTYEX('YourDatabaseName', 'Collation'); to confirm the change persisted in the system metadata.
  • Alternative Solution: If altering production collations is too risky, wrap the specific problematic column in a persisted computed column with the correct collation applied, allowing you to index it without touching the original schema.