Uniqueness & Duplicate Detection

The Uniqueness tab helps you prevent duplicate records by defining constraints that check for matching values before records are saved.

What are Uniqueness Constraints?

Uniqueness constraints are rules that check whether a new or updated record would create a duplicate. They can:

Block saves when duplicates are detected
Warn users about potential duplicates while still allowing saves

This prevents data quality issues like duplicate contacts, duplicate invoices, or duplicate entries that can cause confusion and errors.

Accessing the Uniqueness Tab

Go to Settings > Modules
Select your module
Click the Uniqueness tab

Constraint Types

Coherence supports three types of uniqueness constraints:

Simple Unique

A single field must have unique values across all records.

Use cases:

Email address (each contact has a unique email)
Invoice number (no two invoices share a number)
SKU (product identifiers must be unique)
External ID (integration identifiers)

Composite Unique

A combination of fields must be unique together. Individual field values can repeat, but the combination cannot.

Use cases:

First Name + Last Name + Company (same name at different companies is OK)
Product + Variant + Size (unique SKU combinations)
Year + Month + Sequence (date-based numbering)

Duplicate Detection Rule

Flexible OR-based rules for detecting potential duplicates. Unlike simple uniqueness, these rules support multiple matching conditions and different match types.

Use cases:

Email matches exactly OR (First Name + Last Name + Phone) matches
Complex duplicate detection for merging workflows
Fuzzy matching with normalized values

Creating a Constraint

Click Add Constraint in the Uniqueness tab
Fill in the constraint settings:

Basic Settings

Setting	Description
Name	Descriptive name (e.g., "Unique Email")
Description	Optional explanation of the constraint
Constraint Type	Simple Unique, Composite Unique, or Duplicate Rule

Field Selection

For Simple Unique: Select one field that must have unique values.

For Composite Unique: Select two or more fields. Check each field to include it. The combination of selected fields must be unique.

For Duplicate Detection Rules: Build rules with AND/OR logic:

Each rule is a set of field conditions
Multiple rules are combined with OR (match if ANY rule matches)
Within a rule, multiple fields are combined with AND (all must match)

Match Types (Duplicate Rules Only)

Type	Behavior
Exact Match	Values must be identical
Case Insensitive	Ignores uppercase/lowercase ("John" = "john")
Normalized	Ignores spaces, special characters, and case

Enforcement Mode

Mode	Behavior
Block	Prevents saving if a duplicate is detected
Warn	Shows a warning but allows the save

Choose Block for strict data integrity (like invoice numbers). Choose Warn for soft matching where duplicates are possible but discouraged.

Active Toggle

Enable or disable the constraint without deleting it.

Click Create to save the constraint

Managing Constraints

Editing Constraints

Find the constraint in the list
Click the pencil icon
Update settings
Click Save Changes

Deleting Constraints

Find the constraint to remove
Click the trash icon
Confirm deletion

Disabling Constraints

Toggle the Active switch off to disable a constraint without deleting it.

Constraint Display

Each constraint shows:

Element	Description
Icon	Key (simple), Layers (composite), or Search (rule)
Name	Constraint identifier
Type	The constraint type
Enforcement	"Blocks Save" or "Warns Only"
Fields	Which fields are checked
Status	Active or Disabled badge

Example Configurations

Unique Email Address

Setting	Value
Name	Unique Email
Type	Simple Unique
Field	Email
Enforcement	Block

Unique Name per Company

Setting	Value
Name	Unique Contact per Company
Type	Composite Unique
Fields	First Name, Last Name, Company
Enforcement	Warn

Flexible Duplicate Detection

Setting	Value
Name	Potential Duplicate Contact
Type	Duplicate Detection Rule
Rule 1	Email (exact match)
Rule 2	First Name (case insensitive) AND Last Name (case insensitive) AND Phone (normalized)
Enforcement	Warn

This example warns about duplicates if:

Email matches exactly, OR
First name AND last name AND phone all match (with fuzzy matching)

How Constraints Work

During Record Creation

User fills in the create form
Before saving, Coherence checks all active constraints
If a constraint matches:
- Block: Error message, save prevented
- Warn: Warning message, user can choose to save anyway

During Record Editing

Same behavior as creation - constraints are checked against all other records (excluding the current one).

What Gets Checked

Only active constraints are evaluated
Empty/null fields are typically skipped in matching
Matching is done according to the specified match type

Best Practices

Start with Essential Uniqueness

Begin with the most important unique identifiers:

Email addresses
Invoice/order numbers
External system IDs
Product SKUs

Use Appropriate Enforcement

Block for true business keys (invoice numbers, IDs)
Warn for user-friendly duplicate detection (contacts, leads)

Consider User Experience

Too many blocking constraints can frustrate users. Use warnings for "likely duplicates" and only block for "definitely duplicates."

Name Constraints Clearly

Good names help users understand constraint errors:

✅ "Unique Email Address"
✅ "One Contact per Company"
❌ "Constraint 1"

Test with Real Data

Create test records to verify constraints work as expected before publishing the module.