Troubleshooting Errors In Complex Sharepoint Column Validation Formulas
Common Root Causes of Formula Validation Failures in SharePoint Columns
Formula validation rules in SharePoint columns can fail to execute as expected due to various syntactical, logical, and data-related issues. Identifying the root cause of the validation error is key to debugging SharePoint column formulas.
Syntax Errors in Column Validation Formulas
Syntax errors occur when the column formula contains invalid SharePoint formula syntax. Common syntax errors include missing parentheses, incorrect operator usage, misspelled column references, etc. Syntax errors must be fixed before logical errors can be addressed.
Data Type Mismatches in Validation Formulas
Data type errors occur when operations are performed between mismatched data types, such as combining text with numbers or dates. Type conversion may be required within the formula to avoid data type conflicts.
Circular References within Column Validation Formulas
Circular reference errors occur when a column formula refers back to the value it is trying to validate. This creates an infinite loop and causes the validation to fail. Circular references must be removed.
Formula Character Limits in SharePoint Columns
SharePoint column formulas have character limits between 2000 and 4000 depending on SharePoint version. Lengthy or complex column validations may exceed the limit and require refactoring into multiple columns.
Techniques for Debugging Faulty Validation Formulas
Several techniques can be utilized to inspect, test, and debug faulty column validation formulas.
Verifying Formula Syntax
Paste the formula into a text editor to visually inspect for syntax issues. Check for unclosed parentheses, missing quotes, invalid operators, misspellings, etc. Fix any identified syntax issues.
Printing Intermediate Values
Inject TEXT() statements within the formula to print intermediate values to the validation error message. Analyze if inputs/outputs match expected values.
Commenting Out Formula Sections
Wrap sections of complex formulas in comments (/* */) and retest to isolate any areas triggering the error. Then uncomment section by section.
Segregating into Multiple Columns
Break apart lengthy formulas into individual columns with discrete validation steps. Helps avoid length limits and narrows down failure points.
Remediation of Common Column Validation Errors
Many column validation failures stem from predictable issues when handling input data or exceptions.
Managing Empty or Blank Values
Use ISBLANK() or LEN() > 0 checks to prevent errors when empty fields are supplied to the formula.
Trimming Spaces from Text Values
TRIM() function strips spaces from text used in comparisons and operations to avoid mismatches.
Type Converting Inputs
Convert or cast inputs to expected data types using TEXT(), NUMBERVALUE(), etc. to avoid type conflicts.
Handling Potential Division By Zero Errors
Wrap denominator terms in IF() logic to use a safe default if 0 to avoid runtime errors.
Best Practices for Column Validation Formulas
Keep these tips in mind when architecting validation rules.
Simplicity of Validation Logic
Formulas should be straightforward. Complex formulas are harder to troubleshoot and maintain.
Early Validation of Data
Validate as early as possible – when data is first input rather than allowing bad data to accrue.
Use Clear, Descriptive Error Messages
Customize error messages so its obvious to end users what correction is required when validation fails.
Rigorous Testing of Validation Logic
Thoroughly test validation with different input value combinations to identify shortcomings.
Example Column Validation Formula Patterns
Some useful column validation formula use cases are:
Enforcing Proper Email Address Format
Use a regular expression to check if text input matches standard email pattern
Number Range Checking
Check if number is within an acceptable minimum and maximum range
Dates After or Before Relative Dates
Confirm date field is not before today’s date or past a deadline
Guaranteeing Unique Entries
Lookup text input value against existing items in a SharePoint list
Additional Resources for Column Validation Formulas
Use these links for more formula examples and troubleshooting tips:
Microsoft Formula Reference
Microsoft documentation with editor, templates, functions list
SharePoint Community Discussions
Ask questions and search existing threads on column formulas
SharePoint Column Validation Training
Online courses and videos focused specifically on column validations
