<p>Raised when a SIGNAL or RESIGNAL statement repeats the same condition information item in its SET clause.</p>
<p>MySQL Error 1641 ER_DUP_SIGNAL_SET occurs when a SIGNAL or RESIGNAL statement lists the same condition item twice in its SET clause. Delete the duplicate key or rename it, then rerun the statement to resolve the error.</p>
Duplicate condition information item '%s'
MySQL raises error 1641 with condition name ER_DUP_SIGNAL_SET when a SIGNAL or RESIGNAL statement includes duplicate assignments to the same condition information item in its SET clause.
The parser sees two entries for a key such as MESSAGE_TEXT, MYSQL_ERRNO, or SQLSTATE and stops compilation, preventing your stored procedure or trigger from being created or executed.
This is a compile-time syntax error, so no data modifications occur, but the procedure or batch will not run until fixed.
Understanding why the duplication happened helps you correct your error-handling logic and keep custom exceptions reliable.
Duplicate keys often appear after copy-pasting code, merging branches, or performing automated find-and-replace operations in large stored programs.
If dynamic SQL constructs SIGNAL statements from variables, logic errors can accidentally add an item twice.
Refactoring that moves condition items into helper routines can also introduce duplication when both old and new code remain.
Locate every SIGNAL or RESIGNAL statement flagged by the error and inspect its SET clause. Ensure each condition item appears only once.
If you need to set multiple values, pick distinct keys like MESSAGE_TEXT, MYSQL_ERRNO, and CONSTRAINT_NAME.
After removing duplicates, re-execute the script or recreate the stored routine to confirm the fix.
In triggers, ensure framework-generated code does not append an extra MESSAGE_TEXT assignment.
In stored procedures, consolidate error-handling branches so only one SET clause is generated.
When using Galaxy, inline linting highlights duplicate keys instantly, letting you correct them before saving.
Use consistent templates for SIGNAL statements and review them during code reviews.
Add a unit test that compiles procedures in a CI pipeline to catch syntax errors early.
Galaxy’s real-time syntax checker and version control help track changes and prevent duplicate condition items.
Error 1642 ER_SIGNAL_TOO_MANY_ITEMS occurs when the SET clause lists more than the allowed number of items. Remove extras to fix.
Error 1644 ER_SIGNAL_WARN triggers when SIGNAL specifies SQLSTATE class 01 (warning). Change SQLSTATE or use RESIGNAL to handle warnings properly.
Developers often copy an existing SIGNAL clause and forget to remove the original line, leaving two identical keys.
Frameworks or scripts that build error-handling blocks may unintentionally append duplicate condition items during loops.
When two branches modify the same SIGNAL statement, a merge can keep both versions, resulting in duplication.
Building SIGNAL text via CONCAT can duplicate keys if input parameters already include them.
Raised when the SET clause specifies more than seven condition items. Remove extras to resolve.
Occurs when SIGNAL sets a warning SQLSTATE that conflicts with the statement context. Use RESIGNAL or a proper error code.
Indicates that a referenced stored procedure was not found, often surfaced after compilation failures like ER_DUP_SIGNAL_SET.
No data is modified because the error stops compilation before execution.
No. Each condition item must be unique within the SET clause.
All maintained MySQL versions from 5.5 onward include this check.
Galaxy highlights duplicate keys in real time and blocks storing invalid routines, catching the issue before deploy.
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