feat: add support for trigger UPDATE OF columns (#342)

internal/diff/trigger.go

@@ -46,6 +46,16 @@ func triggersEqual(old, new *ir.Trigger) bool {
 		}
 	}
 
+	// Compare update columns
+	if len(old.UpdateColumns) != len(new.UpdateColumns) {
+		return false
+	}
+	for i, col := range old.UpdateColumns {
+		if col != new.UpdateColumns[i] {
+			return false
+		}
+	}
+
 	// Compare constraint trigger properties
 	if old.IsConstraint != new.IsConstraint {
 		return false
@@ -215,7 +225,11 @@ func generateTriggerSQLWithMode(trigger *ir.Trigger, targetSchema string) string
 	for _, orderEvent := range eventOrder {
 		for _, triggerEvent := range trigger.Events {
 			if triggerEvent == orderEvent {
-				events = append(events, string(triggerEvent))
+				if triggerEvent == ir.TriggerEventUpdate && len(trigger.UpdateColumns) > 0 {
+					events = append(events, "UPDATE OF "+strings.Join(trigger.UpdateColumns, ", "))
+				} else {
+					events = append(events, string(triggerEvent))
+				}
 				break
 			}
 		}

ir/inspector.go

@@ -1452,6 +1452,65 @@ func extractWhenClauseFromTriggerDef(triggerDef string) string {
 	return strings.TrimSpace(triggerDef[start:end])
 }
 
+// extractUpdateColumnsFromTriggerDef extracts column names from UPDATE OF col1, col2 in a trigger definition
+// returned by pg_get_triggerdef(). The format is:
+// "CREATE TRIGGER name BEFORE INSERT OR UPDATE OF col1, col2 ON table ..."
+func extractUpdateColumnsFromTriggerDef(triggerDef string) []string {
+	upper := strings.ToUpper(triggerDef)
+	updateOfIdx := strings.Index(upper, "UPDATE OF ")
+	if updateOfIdx == -1 {
+		return nil
+	}
+
+	// Start after "UPDATE OF "
+	start := updateOfIdx + len("UPDATE OF ")
+
+	// Find " ON " which terminates the event/column list
+	onIdx := strings.Index(upper[start:], " ON ")
+	if onIdx == -1 {
+		return nil
+	}
+
+	// Extract the column list substring
+	colListStr := strings.TrimSpace(triggerDef[start : start+onIdx])
+
+	// Handle potential " OR " separating additional events after the columns
+	// e.g., "UPDATE OF col1, col2 OR DELETE ON ..."
+	// We need to check if there's an OR followed by another event keyword
+	eventKeywords := []string{"INSERT", "UPDATE", "DELETE", "TRUNCATE"}
+	parts := strings.Split(colListStr, " OR ")
+	// Only keep the first part (column list); the rest would be other events
+	if len(parts) > 1 {
+		// Check if subsequent parts are event keywords
+		for i := 1; i < len(parts); i++ {
+			trimmed := strings.TrimSpace(strings.ToUpper(parts[i]))
+			isEvent := false
+			for _, kw := range eventKeywords {
+				if trimmed == kw || strings.HasPrefix(trimmed, kw+" ") {
+					isEvent = true
+					break
+				}
+			}
+			if isEvent {
+				colListStr = strings.TrimSpace(parts[0])
+				break
+			}
+		}
+	}
+
+	// Split by comma and trim each column name
+	rawCols := strings.Split(colListStr, ",")
+	var columns []string
+	for _, col := range rawCols {
+		col = strings.TrimSpace(col)
+		if col != "" {
+			columns = append(columns, col)
+		}
+	}
+
+	return columns
+}
+
 // extractFunctionCallFromTriggerDef extracts the function call (with arguments) from a trigger definition
 // returned by pg_get_triggerdef(). The format is:
 // "... EXECUTE FUNCTION function_name(arg1, arg2)"
@@ -1548,6 +1607,12 @@ func (i *Inspector) buildTriggers(ctx context.Context, schema *IR, targetSchema
 			condition = extractWhenClauseFromTriggerDef(triggerRow.TriggerDefinition.String)
 		}
 
+		// Extract UPDATE OF columns from trigger definition (only for triggers with UPDATE events)
+		var updateColumns []string
+		if triggerRow.TriggerDefinition.Valid && triggerRow.TriggerType&triggerTypeUpdate != 0 {
+			updateColumns = extractUpdateColumnsFromTriggerDef(triggerRow.TriggerDefinition.String)
+		}
+
 		// Extract transition table names
 		oldTable := ""
 		if triggerRow.OldTable.Valid {
@@ -1577,6 +1642,7 @@ func (i *Inspector) buildTriggers(ctx context.Context, schema *IR, targetSchema
 			Table:             tableName,
 			Timing:            timing,
 			Events:            events,
+			UpdateColumns:     updateColumns,
 			Level:             level,
 			Function:          functionCall,
 			Condition:         condition,

ir/ir.go

@@ -278,8 +278,9 @@ type Trigger struct {
 	Table             string         `json:"table"`
 	Name              string         `json:"name"`
 	Timing            TriggerTiming  `json:"timing"` // BEFORE, AFTER, INSTEAD OF
-	Events            []TriggerEvent `json:"events"` // INSERT, UPDATE, DELETE
-	Level             TriggerLevel   `json:"level"`  // ROW, STATEMENT
+	Events            []TriggerEvent `json:"events"`                        // INSERT, UPDATE, DELETE
+	UpdateColumns     []string       `json:"update_columns,omitempty"`      // Column names for UPDATE OF
+	Level             TriggerLevel   `json:"level"`                         // ROW, STATEMENT
 	Function          string         `json:"function"`
 	Condition         string         `json:"condition,omitempty"` // WHEN condition
 	Comment           string         `json:"comment,omitempty"`

testdata/diff/create_trigger/add_trigger/diff.sql

@@ -8,6 +8,11 @@ CREATE OR REPLACE TRIGGER employees_last_modified_trigger
     FOR EACH ROW
     EXECUTE FUNCTION update_last_modified();
 
+CREATE OR REPLACE TRIGGER employees_salary_update_trigger
+    BEFORE UPDATE OF salary ON employees
+    FOR EACH ROW
+    EXECUTE FUNCTION update_last_modified();
+
 CREATE OR REPLACE TRIGGER employees_truncate_log_trigger
     AFTER TRUNCATE ON employees
     FOR EACH STATEMENT

testdata/diff/create_trigger/add_trigger/new.sql

@@ -23,6 +23,11 @@ CREATE TRIGGER employees_insert_timestamp_trigger
     FOR EACH ROW
     EXECUTE FUNCTION public.update_last_modified();
 
+CREATE TRIGGER employees_salary_update_trigger
+    BEFORE UPDATE OF salary ON public.employees
+    FOR EACH ROW
+    EXECUTE FUNCTION public.update_last_modified();
+
 CREATE TRIGGER employees_truncate_log_trigger
     AFTER TRUNCATE ON public.employees
     FOR EACH STATEMENT

testdata/diff/create_trigger/add_trigger/plan.json

@@ -20,6 +20,12 @@
           "operation": "create",
           "path": "public.employees.employees_last_modified_trigger"
         },
+        {
+          "sql": "CREATE OR REPLACE TRIGGER employees_salary_update_trigger\n    BEFORE UPDATE OF salary ON employees\n    FOR EACH ROW\n    EXECUTE FUNCTION update_last_modified();",
+          "type": "table.trigger",
+          "operation": "create",
+          "path": "public.employees.employees_salary_update_trigger"
+        },
         {
           "sql": "CREATE OR REPLACE TRIGGER employees_truncate_log_trigger\n    AFTER TRUNCATE ON employees\n    FOR EACH STATEMENT\n    EXECUTE FUNCTION update_last_modified();",
           "type": "table.trigger",

testdata/diff/create_trigger/add_trigger/plan.sql

@@ -8,6 +8,11 @@ CREATE OR REPLACE TRIGGER employees_last_modified_trigger
     FOR EACH ROW
     EXECUTE FUNCTION update_last_modified();
 
+CREATE OR REPLACE TRIGGER employees_salary_update_trigger
+    BEFORE UPDATE OF salary ON employees
+    FOR EACH ROW
+    EXECUTE FUNCTION update_last_modified();
+
 CREATE OR REPLACE TRIGGER employees_truncate_log_trigger
     AFTER TRUNCATE ON employees
     FOR EACH STATEMENT

testdata/diff/create_trigger/add_trigger/plan.txt

@@ -8,6 +8,7 @@ Tables:
   ~ employees
     + employees_insert_timestamp_trigger (trigger)
     + employees_last_modified_trigger (trigger)
+    + employees_salary_update_trigger (trigger)
     + employees_truncate_log_trigger (trigger)
 
 Views:
@@ -27,6 +28,11 @@ CREATE OR REPLACE TRIGGER employees_last_modified_trigger
     FOR EACH ROW
     EXECUTE FUNCTION update_last_modified();
 
+CREATE OR REPLACE TRIGGER employees_salary_update_trigger
+    BEFORE UPDATE OF salary ON employees
+    FOR EACH ROW
+    EXECUTE FUNCTION update_last_modified();
+
 CREATE OR REPLACE TRIGGER employees_truncate_log_trigger
     AFTER TRUNCATE ON employees
     FOR EACH STATEMENT

testdata/diff/create_trigger/alter_trigger/diff.sql

@@ -1,5 +1,5 @@
 CREATE OR REPLACE TRIGGER employees_last_modified_trigger
-    BEFORE INSERT OR UPDATE ON employees
+    BEFORE INSERT OR UPDATE OF salary ON employees
     FOR EACH ROW
     WHEN (((NEW.salary IS NOT NULL)))
     EXECUTE FUNCTION update_last_modified();

testdata/diff/create_trigger/alter_trigger/new.sql

@@ -14,7 +14,7 @@ END;
 $$ LANGUAGE plpgsql;
 
 CREATE TRIGGER employees_last_modified_trigger
-    BEFORE INSERT OR UPDATE ON public.employees
+    BEFORE INSERT OR UPDATE OF salary ON public.employees
     FOR EACH ROW
     WHEN (NEW.salary IS NOT NULL)
     EXECUTE FUNCTION public.update_last_modified();

testdata/diff/create_trigger/alter_trigger/plan.json

@@ -9,7 +9,7 @@
     {
       "steps": [
         {
-          "sql": "CREATE OR REPLACE TRIGGER employees_last_modified_trigger\n    BEFORE INSERT OR UPDATE ON employees\n    FOR EACH ROW\n    WHEN (((NEW.salary IS NOT NULL)))\n    EXECUTE FUNCTION update_last_modified();",
+          "sql": "CREATE OR REPLACE TRIGGER employees_last_modified_trigger\n    BEFORE INSERT OR UPDATE OF salary ON employees\n    FOR EACH ROW\n    WHEN (((NEW.salary IS NOT NULL)))\n    EXECUTE FUNCTION update_last_modified();",
           "type": "table.trigger",
           "operation": "alter",
           "path": "public.employees.employees_last_modified_trigger"

testdata/diff/create_trigger/alter_trigger/plan.sql

@@ -1,5 +1,5 @@
 CREATE OR REPLACE TRIGGER employees_last_modified_trigger
-    BEFORE INSERT OR UPDATE ON employees
+    BEFORE INSERT OR UPDATE OF salary ON employees
     FOR EACH ROW
     WHEN (((NEW.salary IS NOT NULL)))
     EXECUTE FUNCTION update_last_modified();

testdata/diff/create_trigger/alter_trigger/plan.txt

@@ -11,7 +11,7 @@ DDL to be executed:
 --------------------------------------------------
 
 CREATE OR REPLACE TRIGGER employees_last_modified_trigger
-    BEFORE INSERT OR UPDATE ON employees
+    BEFORE INSERT OR UPDATE OF salary ON employees
     FOR EACH ROW
     WHEN (((NEW.salary IS NOT NULL)))
     EXECUTE FUNCTION update_last_modified();