fix: EXCLUDE constraint incorrectly dumped as regular INDEX (#281)

internal/diff/constraint.go

@@ -62,6 +62,9 @@ func generateConstraintSQL(constraint *ir.Constraint, targetSchema string) strin
 			result += " NOT VALID"
 		}
 		return result
+	case ir.ConstraintTypeExclusion:
+		// Use the full definition from pg_get_constraintdef()
+		return fmt.Sprintf("CONSTRAINT %s %s", ir.QuoteIdentifier(constraint.Name), constraint.ExclusionDefinition)
 	default:
 		return ""
 	}
@@ -79,6 +82,7 @@ func getInlineConstraintsForTable(table *ir.Table) []*ir.Constraint {
 	var uniques []*ir.Constraint
 	var foreignKeys []*ir.Constraint
 	var checkConstraints []*ir.Constraint
+	var exclusionConstraints []*ir.Constraint
 
 	for _, constraintName := range constraintNames {
 		constraint := table.Constraints[constraintName]
@@ -95,14 +99,17 @@ func getInlineConstraintsForTable(table *ir.Table) []*ir.Constraint {
 			foreignKeys = append(foreignKeys, constraint)
 		case ir.ConstraintTypeCheck:
 			checkConstraints = append(checkConstraints, constraint)
+		case ir.ConstraintTypeExclusion:
+			exclusionConstraints = append(exclusionConstraints, constraint)
 		}
 	}
 
-	// Add constraints in order: PRIMARY KEY, UNIQUE, FOREIGN KEY, CHECK
+	// Add constraints in order: PRIMARY KEY, UNIQUE, FOREIGN KEY, CHECK, EXCLUDE
 	inlineConstraints = append(inlineConstraints, primaryKeys...)
 	inlineConstraints = append(inlineConstraints, uniques...)
 	inlineConstraints = append(inlineConstraints, foreignKeys...)
 	inlineConstraints = append(inlineConstraints, checkConstraints...)
+	inlineConstraints = append(inlineConstraints, exclusionConstraints...)
 
 	return inlineConstraints
 }
@@ -125,6 +132,9 @@ func constraintsEqual(old, new *ir.Constraint) bool {
 	if old.CheckClause != new.CheckClause {
 		return false
 	}
+	if old.ExclusionDefinition != new.ExclusionDefinition {
+		return false
+	}
 
 	// Foreign key specific properties (this is the key fix!)
 	if old.DeleteRule != new.DeleteRule {
@@ -153,8 +163,8 @@ func constraintsEqual(old, new *ir.Constraint) bool {
 		return false
 	}
 
-	// Compare columns (skip for CHECK constraints as column detection may differ between parser and inspector)
-	if old.Type != ir.ConstraintTypeCheck {
+	// Compare columns (skip for CHECK and EXCLUDE constraints as column detection may differ)
+	if old.Type != ir.ConstraintTypeCheck && old.Type != ir.ConstraintTypeExclusion {
 		if len(old.Columns) != len(new.Columns) {
 			return false
 		}

internal/diff/table.go

@@ -887,6 +887,20 @@ func (td *tableDiff) generateAlterTableStatements(targetSchema string, collector
 				CanRunInTransaction: true,
 			}
 			collector.collect(context, sql)
+
+		case ir.ConstraintTypeExclusion:
+			tableName := getTableNameWithSchema(td.Table.Schema, td.Table.Name, targetSchema)
+			sql := fmt.Sprintf("ALTER TABLE %s\nADD CONSTRAINT %s %s;",
+				tableName, ir.QuoteIdentifier(constraint.Name), constraint.ExclusionDefinition)
+
+			context := &diffContext{
+				Type:                DiffTypeTableConstraint,
+				Operation:           DiffOperationCreate,
+				Path:                fmt.Sprintf("%s.%s.%s", td.Table.Schema, td.Table.Name, constraint.Name),
+				Source:              constraint,
+				CanRunInTransaction: true,
+			}
+			collector.collect(context, sql)
 		}
 	}
 
@@ -946,6 +960,10 @@ func (td *tableDiff) generateAlterTableStatements(targetSchema string, collector
 			}
 			addSQL = fmt.Sprintf("ALTER TABLE %s\nADD CONSTRAINT %s PRIMARY KEY (%s);",
 				tableName, ir.QuoteIdentifier(constraint.Name), strings.Join(columnNames, ", "))
+
+		case ir.ConstraintTypeExclusion:
+			addSQL = fmt.Sprintf("ALTER TABLE %s\nADD CONSTRAINT %s %s;",
+				tableName, ir.QuoteIdentifier(constraint.Name), constraint.ExclusionDefinition)
 		}
 
 		addContext := &diffContext{

ir/inspector.go

@@ -463,6 +463,8 @@ func (i *Inspector) buildConstraints(ctx context.Context, schema *IR, targetSche
 				cType = ConstraintTypeForeignKey
 			case "CHECK":
 				cType = ConstraintTypeCheck
+			case "EXCLUDE":
+				cType = ConstraintTypeExclusion
 			default:
 				continue // Skip unknown constraint types
 			}
@@ -509,6 +511,13 @@ func (i *Inspector) buildConstraints(ctx context.Context, schema *IR, targetSche
 				}
 			}
 
+			// Handle exclusion constraints
+			if cType == ConstraintTypeExclusion {
+				if exclDef := i.safeInterfaceToString(constraint.ExclusionDefinition); exclDef != "" && exclDef != "<nil>" {
+					c.ExclusionDefinition = exclDef
+				}
+			}
+
 			// Set validation state from database
 			c.IsValid = constraint.IsValid
 

ir/ir.go

@@ -204,21 +204,22 @@ type Sequence struct {
 
 // Constraint represents a table constraint
 type Constraint struct {
-	Schema            string              `json:"schema"`
-	Table             string              `json:"table"`
-	Name              string              `json:"name"`
-	Type              ConstraintType      `json:"type"`
-	Columns           []*ConstraintColumn `json:"columns"`
-	ReferencedSchema  string              `json:"referenced_schema,omitempty"`
-	ReferencedTable   string              `json:"referenced_table,omitempty"`
-	ReferencedColumns []*ConstraintColumn `json:"referenced_columns,omitempty"`
-	CheckClause       string              `json:"check_clause,omitempty"`
-	DeleteRule        string              `json:"delete_rule,omitempty"`
-	UpdateRule        string              `json:"update_rule,omitempty"`
-	Deferrable        bool                `json:"deferrable,omitempty"`
-	InitiallyDeferred bool                `json:"initially_deferred,omitempty"`
-	IsValid           bool                `json:"is_valid,omitempty"`
-	Comment           string              `json:"comment,omitempty"`
+	Schema              string              `json:"schema"`
+	Table               string              `json:"table"`
+	Name                string              `json:"name"`
+	Type                ConstraintType      `json:"type"`
+	Columns             []*ConstraintColumn `json:"columns"`
+	ReferencedSchema    string              `json:"referenced_schema,omitempty"`
+	ReferencedTable     string              `json:"referenced_table,omitempty"`
+	ReferencedColumns   []*ConstraintColumn `json:"referenced_columns,omitempty"`
+	CheckClause         string              `json:"check_clause,omitempty"`
+	ExclusionDefinition string              `json:"exclusion_definition,omitempty"` // Full EXCLUDE definition from pg_get_constraintdef()
+	DeleteRule          string              `json:"delete_rule,omitempty"`
+	UpdateRule          string              `json:"update_rule,omitempty"`
+	Deferrable          bool                `json:"deferrable,omitempty"`
+	InitiallyDeferred   bool                `json:"initially_deferred,omitempty"`
+	IsValid             bool                `json:"is_valid,omitempty"`
+	Comment             string              `json:"comment,omitempty"`
 }
 
 // ConstraintColumn represents a column within a constraint with its position

ir/normalize.go

@@ -877,10 +877,22 @@ func normalizeConstraint(constraint *Constraint) {
 		return
 	}
 
-	// Only normalize CHECK constraints - other constraint types are already consistent
+	// Only normalize CHECK and EXCLUDE constraints - other constraint types are already consistent
 	if constraint.Type == ConstraintTypeCheck && constraint.CheckClause != "" {
 		constraint.CheckClause = normalizeCheckClause(constraint.CheckClause)
 	}
+	if constraint.Type == ConstraintTypeExclusion && constraint.ExclusionDefinition != "" {
+		constraint.ExclusionDefinition = normalizeExclusionDefinition(constraint.ExclusionDefinition)
+	}
+}
+
+// normalizeExclusionDefinition normalizes EXCLUDE constraint definitions.
+//
+// pg_get_constraintdef() returns the full definition like:
+// "EXCLUDE USING gist (range_col WITH &&)"
+// We keep it as-is since both desired and current state come from pg_get_constraintdef().
+func normalizeExclusionDefinition(definition string) string {
+	return strings.TrimSpace(definition)
 }
 
 // normalizeCheckClause normalizes CHECK constraint expressions.

ir/queries/queries.sql

@@ -312,6 +312,7 @@ SELECT
     COALESCE(fa.attname, '') AS foreign_column_name,
     COALESCE(fa.attnum, 0) AS foreign_ordinal_position,
     CASE WHEN c.contype = 'c' THEN pg_get_constraintdef(c.oid, true) ELSE NULL END AS check_clause,
+    CASE WHEN c.contype = 'x' THEN pg_get_constraintdef(c.oid, true) ELSE NULL END AS exclusion_definition,
     CASE c.confdeltype
         WHEN 'a' THEN 'NO ACTION'
         WHEN 'r' THEN 'RESTRICT'
@@ -374,7 +375,7 @@ WITH index_base AS (
         AND NOT EXISTS (
             SELECT 1 FROM pg_constraint c
             WHERE c.conindid = idx.indexrelid
-            AND c.contype IN ('u', 'p')
+            AND c.contype IN ('u', 'p', 'x')
         )
         AND n.nspname NOT IN ('information_schema', 'pg_catalog', 'pg_toast')
         AND n.nspname NOT LIKE 'pg_temp_%'
@@ -460,7 +461,7 @@ WITH index_base AS (
         AND NOT EXISTS (
             SELECT 1 FROM pg_constraint c
             WHERE c.conindid = idx.indexrelid
-            AND c.contype IN ('u', 'p')
+            AND c.contype IN ('u', 'p', 'x')
         )
         AND n.nspname = $1
 )
@@ -887,6 +888,7 @@ SELECT
     COALESCE(fa.attname, '') AS foreign_column_name,
     COALESCE(fa.attnum, 0) AS foreign_ordinal_position,
     CASE WHEN c.contype = 'c' THEN pg_get_constraintdef(c.oid, true) ELSE NULL END AS check_clause,
+    CASE WHEN c.contype = 'x' THEN pg_get_constraintdef(c.oid, true) ELSE NULL END AS exclusion_definition,
     CASE c.confdeltype
         WHEN 'a' THEN 'NO ACTION'
         WHEN 'r' THEN 'RESTRICT'

testdata/diff/create_table/issue_281_exclude_constraint/diff.sql

@@ -0,0 +1,2 @@
+ALTER TABLE test_table
+ADD CONSTRAINT excl_no_overlap EXCLUDE USING gist (range_col WITH &&);

testdata/diff/create_table/issue_281_exclude_constraint/new.sql

@@ -0,0 +1,6 @@
+CREATE TABLE IF NOT EXISTS test_table (
+    id integer,
+    range_col int4range NOT NULL,
+    CONSTRAINT test_table_pkey PRIMARY KEY (id),
+    CONSTRAINT excl_no_overlap EXCLUDE USING gist (range_col WITH &&)
+);

testdata/diff/create_table/issue_281_exclude_constraint/old.sql

@@ -0,0 +1,5 @@
+CREATE TABLE IF NOT EXISTS test_table (
+    id integer,
+    range_col int4range NOT NULL,
+    CONSTRAINT test_table_pkey PRIMARY KEY (id)
+);

testdata/diff/create_table/issue_281_exclude_constraint/plan.json

@@ -0,0 +1,20 @@
+{
+  "version": "1.0.0",
+  "pgschema_version": "1.7.0",
+  "created_at": "1970-01-01T00:00:00Z",
+  "source_fingerprint": {
+    "hash": "4fbb3d8c221ccc65b31f81678cb19ac44eccc901628273d00cc3e124a6ee6877"
+  },
+  "groups": [
+    {
+      "steps": [
+        {
+          "sql": "ALTER TABLE test_table\nADD CONSTRAINT excl_no_overlap EXCLUDE USING gist (range_col WITH &&);",
+          "type": "table.constraint",
+          "operation": "create",
+          "path": "public.test_table.excl_no_overlap"
+        }
+      ]
+    }
+  ]
+}

testdata/diff/create_table/issue_281_exclude_constraint/plan.sql

@@ -0,0 +1,2 @@
+ALTER TABLE test_table
+ADD CONSTRAINT excl_no_overlap EXCLUDE USING gist (range_col WITH &&);

testdata/diff/create_table/issue_281_exclude_constraint/plan.txt

@@ -0,0 +1,14 @@
+Plan: 1 to modify.
+
+Summary by type:
+  tables: 1 to modify
+
+Tables:
+  ~ test_table
+    + excl_no_overlap (constraint)
+
+DDL to be executed:
+--------------------------------------------------
+
+ALTER TABLE test_table
+ADD CONSTRAINT excl_no_overlap EXCLUDE USING gist (range_col WITH &&);