normalized values on maxSelect change

daos/record_table_sync.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/pocketbase/dbx"
 	"github.com/pocketbase/pocketbase/models"
 	"github.com/pocketbase/pocketbase/models/schema"
 	"github.com/pocketbase/pocketbase/tools/list"
@@ -149,10 +150,104 @@ func (dao *Dao) SyncRecordTableSchema(newCollection *models.Collection, oldColle
 			}
 		}
 
+		if err := txDao.normalizeSingleVsMultipleFieldChanges(newCollection, oldCollection); err != nil {
+			return err
+		}
+
 		return txDao.syncCollectionReferences(newCollection, renamedFieldNames, deletedFieldNames)
 	})
 }
 
+func (dao *Dao) normalizeSingleVsMultipleFieldChanges(newCollection, oldCollection *models.Collection) error {
+	if newCollection.IsView() || oldCollection == nil {
+		return nil // view or not an update
+	}
+
+	return dao.RunInTransaction(func(txDao *Dao) error {
+		for _, newField := range newCollection.Schema.Fields() {
+			oldField := oldCollection.Schema.GetFieldById(newField.Id)
+			if oldField == nil {
+				continue
+			}
+
+			var isNewMultiple bool
+			if opt, ok := newField.Options.(schema.MultiValuer); ok {
+				isNewMultiple = opt.IsMultiple()
+			}
+
+			var isOldMultiple bool
+			if opt, ok := oldField.Options.(schema.MultiValuer); ok {
+				isOldMultiple = opt.IsMultiple()
+			}
+
+			if isOldMultiple == isNewMultiple {
+				continue // no change
+			}
+
+			var updateQuery *dbx.Query
+
+			if !isOldMultiple && isNewMultiple {
+				// single -> multiple (convert to array)
+				updateQuery = txDao.DB().NewQuery(fmt.Sprintf(
+					`UPDATE {{%s}} set [[%s]] = (
+							CASE
+								WHEN COALESCE([[%s]], '') = ''
+								THEN '[]'
+								ELSE (
+									CASE
+										WHEN json_valid([[%s]]) AND json_type([[%s]]) == 'array'
+										THEN [[%s]]
+										ELSE json_array([[%s]])
+									END
+								)
+							END
+						)`,
+					newCollection.Name,
+					newField.Name,
+					newField.Name,
+					newField.Name,
+					newField.Name,
+					newField.Name,
+					newField.Name,
+				))
+			} else {
+				// multiple -> single (keep only the last element)
+				//
+				// note: for file fields the actual files are not deleted
+				// allowing additional custom handling via migration.
+				updateQuery = txDao.DB().NewQuery(fmt.Sprintf(
+					`UPDATE {{%s}} set [[%s]] = (
+						CASE
+							WHEN COALESCE([[%s]], '[]') = '[]'
+							THEN ''
+							ELSE (
+								CASE
+									WHEN json_valid([[%s]]) AND json_type([[%s]]) == 'array'
+									THEN COALESCE(json_extract([[%s]], '$[#-1]'), '')
+									ELSE [[%s]]
+								END
+							)
+						END
+					)`,
+					newCollection.Name,
+					newField.Name,
+					newField.Name,
+					newField.Name,
+					newField.Name,
+					newField.Name,
+					newField.Name,
+				))
+			}
+
+			if _, err := updateQuery.Execute(); err != nil {
+				return err
+			}
+		}
+
+		return nil
+	})
+}
+
 func (dao *Dao) syncCollectionReferences(collection *models.Collection, renamedFieldNames map[string]string, deletedFieldNames []string) error {
 	if len(renamedFieldNames) == 0 && len(deletedFieldNames) == 0 {
 		return nil // nothing to sync

daos/record_table_sync_test.go

@@ -1,12 +1,16 @@
 package daos_test
 
 import (
+	"bytes"
+	"encoding/json"
 	"testing"
 
+	"github.com/pocketbase/dbx"
 	"github.com/pocketbase/pocketbase/models"
 	"github.com/pocketbase/pocketbase/models/schema"
 	"github.com/pocketbase/pocketbase/tests"
 	"github.com/pocketbase/pocketbase/tools/list"
+	"github.com/pocketbase/pocketbase/tools/types"
 )
 
 func TestSyncRecordTableSchema(t *testing.T) {
@@ -117,3 +121,132 @@ func TestSyncRecordTableSchema(t *testing.T) {
 		}
 	}
 }
+
+func TestSingleVsMultipleValuesNormalization(t *testing.T) {
+	app, _ := tests.NewTestApp()
+	defer app.Cleanup()
+
+	collection, err := app.Dao().FindCollectionByNameOrId("demo1")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// mock field changes
+	{
+		selectOneField := collection.Schema.GetFieldByName("select_one")
+		opt := selectOneField.Options.(*schema.SelectOptions)
+		opt.MaxSelect = 2
+	}
+	{
+		selectManyField := collection.Schema.GetFieldByName("select_many")
+		opt := selectManyField.Options.(*schema.SelectOptions)
+		opt.MaxSelect = 1
+	}
+	{
+
+		fileOneField := collection.Schema.GetFieldByName("file_one")
+		opt := fileOneField.Options.(*schema.FileOptions)
+		opt.MaxSelect = 2
+	}
+	{
+		fileManyField := collection.Schema.GetFieldByName("file_many")
+		opt := fileManyField.Options.(*schema.FileOptions)
+		opt.MaxSelect = 1
+
+	}
+	{
+		relOneField := collection.Schema.GetFieldByName("rel_one")
+		opt := relOneField.Options.(*schema.RelationOptions)
+		opt.MaxSelect = types.Pointer(2)
+	}
+	{
+		relManyField := collection.Schema.GetFieldByName("rel_many")
+		opt := relManyField.Options.(*schema.RelationOptions)
+		opt.MaxSelect = types.Pointer(1)
+	}
+
+	if err := app.Dao().SaveCollection(collection); err != nil {
+		t.Fatal(err)
+	}
+
+	type expectation struct {
+		SelectOne  string `db:"select_one"`
+		SelectMany string `db:"select_many"`
+		FileOne    string `db:"file_one"`
+		FileMany   string `db:"file_many"`
+		RelOne     string `db:"rel_one"`
+		RelMany    string `db:"rel_many"`
+	}
+
+	scenarios := []struct {
+		recordId string
+		expected expectation
+	}{
+		{
+			"imy661ixudk5izi",
+			expectation{
+				SelectOne:  `[]`,
+				SelectMany: ``,
+				FileOne:    `[]`,
+				FileMany:   ``,
+				RelOne:     `[]`,
+				RelMany:    ``,
+			},
+		},
+		{
+			"al1h9ijdeojtsjy",
+			expectation{
+				SelectOne:  `["optionB"]`,
+				SelectMany: `optionB`,
+				FileOne:    `["300_Jsjq7RdBgA.png"]`,
+				FileMany:   ``,
+				RelOne:     `["84nmscqy84lsi1t"]`,
+				RelMany:    `oap640cot4yru2s`,
+			},
+		},
+		{
+			"84nmscqy84lsi1t",
+			expectation{
+				SelectOne:  `["optionB"]`,
+				SelectMany: `optionC`,
+				FileOne:    `["test_d61b33QdDU.txt"]`,
+				FileMany:   `test_tC1Yc87DfC.txt`,
+				RelOne:     `[]`,
+				RelMany:    `oap640cot4yru2s`,
+			},
+		},
+	}
+
+	for _, s := range scenarios {
+		result := new(expectation)
+
+		err := app.Dao().DB().Select(
+			"select_one",
+			"select_many",
+			"file_one",
+			"file_many",
+			"rel_one",
+			"rel_many",
+		).From(collection.Name).Where(dbx.HashExp{"id": s.recordId}).One(result)
+		if err != nil {
+			t.Errorf("[%s] Failed to load record: %v", s.recordId, err)
+			continue
+		}
+
+		encodedResult, err := json.Marshal(result)
+		if err != nil {
+			t.Errorf("[%s] Failed to encode result: %v", s.recordId, err)
+			continue
+		}
+
+		encodedExpectation, err := json.Marshal(s.expected)
+		if err != nil {
+			t.Errorf("[%s] Failed to encode expectation: %v", s.recordId, err)
+			continue
+		}
+
+		if !bytes.EqualFold(encodedExpectation, encodedResult) {
+			t.Errorf("[%s] Expected \n%s, \ngot \n%s", s.recordId, encodedExpectation, encodedResult)
+		}
+	}
+}

migrations/1678082970_normalize_single_multiple_values.go

@@ -0,0 +1,104 @@
+package migrations
+
+import (
+	"fmt"
+
+	"github.com/pocketbase/dbx"
+	"github.com/pocketbase/pocketbase/daos"
+	"github.com/pocketbase/pocketbase/models"
+	"github.com/pocketbase/pocketbase/models/schema"
+)
+
+// Normalizes old single and multiple values of MultiValuer fields (file, select, relation).
+func init() {
+	AppMigrations.Register(func(db dbx.Builder) error {
+		dao := daos.New(db)
+
+		collections := []*models.Collection{}
+		if err := dao.CollectionQuery().All(&collections); err != nil {
+			return err
+		}
+
+		for _, c := range collections {
+			if c.IsView() {
+				// skip view collections
+				continue
+			}
+
+			for _, f := range c.Schema.Fields() {
+				opt, ok := f.Options.(schema.MultiValuer)
+				if !ok {
+					continue
+				}
+
+				var updateQuery *dbx.Query
+
+				if opt.IsMultiple() {
+					updateQuery = dao.DB().NewQuery(fmt.Sprintf(
+						`UPDATE {{%s}} set [[%s]] = (
+							CASE
+								WHEN COALESCE([[%s]], '') = ''
+								THEN '[]'
+								ELSE (
+									CASE
+										WHEN json_valid([[%s]]) AND json_type([[%s]]) == 'array'
+										THEN [[%s]]
+										ELSE json_array([[%s]])
+									END
+								)
+							END
+						)`,
+						c.Name,
+						f.Name,
+						f.Name,
+						f.Name,
+						f.Name,
+						f.Name,
+						f.Name,
+					))
+				} else {
+					updateQuery = dao.DB().NewQuery(fmt.Sprintf(
+						`UPDATE {{%s}} set [[%s]] = (
+							CASE
+								WHEN COALESCE([[%s]], '[]') = '[]'
+								THEN ''
+								ELSE (
+									CASE
+										WHEN json_valid([[%s]]) AND json_type([[%s]]) == 'array'
+										THEN COALESCE(json_extract([[%s]], '$[#-1]'), '')
+										ELSE [[%s]]
+									END
+								)
+							END
+						)`,
+						c.Name,
+						f.Name,
+						f.Name,
+						f.Name,
+						f.Name,
+						f.Name,
+						f.Name,
+					))
+				}
+
+				if _, err := updateQuery.Execute(); err != nil {
+					return err
+				}
+			}
+		}
+
+		// trigger view query update after the records normalization
+		// (ignore save error in case of invalid query to allow users to change it from the UI)
+		for _, c := range collections {
+			if !c.IsView() {
+				continue
+			}
+
+			dao.SaveCollection(c)
+		}
+
+		return nil
+	}, func(db dbx.Builder) error {
+		return nil
+	})
+}

models/schema/schema_field.go

@@ -321,7 +321,7 @@ func (f *SchemaField) PrepareValue(value any) any {
 		val := list.ToUniqueStringSlice(value)
 
 		options, _ := f.Options.(*SelectOptions)
-		if options.MaxSelect <= 1 {
+		if !options.IsMultiple() {
 			if len(val) > 0 {
 				return val[len(val)-1] // the last selected
 			}
@@ -333,7 +333,7 @@ func (f *SchemaField) PrepareValue(value any) any {
 		val := list.ToUniqueStringSlice(value)
 
 		options, _ := f.Options.(*FileOptions)
-		if options.MaxSelect <= 1 {
+		if !options.IsMultiple() {
 			if len(val) > 0 {
 				return val[len(val)-1] // the last selected
 			}
@@ -345,7 +345,7 @@ func (f *SchemaField) PrepareValue(value any) any {
 		ids := list.ToUniqueStringSlice(value)
 
 		options, _ := f.Options.(*RelationOptions)
-		if options.MaxSelect != nil && *options.MaxSelect <= 1 {
+		if !options.IsMultiple() {
 			if len(ids) > 0 {
 				return ids[len(ids)-1] // the last selected
 			}
@@ -399,7 +399,12 @@ func (f *SchemaField) PrepareValueWithModifier(baseValue any, modifier string, m
 
 // -------------------------------------------------------------------
 
-// FieldOptions interfaces that defines common methods that every field options struct has.
+// MultiValuer defines common interface methods that every multi-valued (eg. with MaxSelect) field option struct has.
+type MultiValuer interface {
+	IsMultiple() bool
+}
+
+// FieldOptions defines common interface methods that every field option struct has.
 type FieldOptions interface {
 	Validate() error
 }
@@ -564,6 +569,12 @@ func (o SelectOptions) Validate() error {
 	)
 }
 
+// IsMultiple implements MultiValuer interface and checks whether the
+// current field options support multiple values.
+func (o SelectOptions) IsMultiple() bool {
+	return o.MaxSelect > 1
+}
+
 // -------------------------------------------------------------------
 
 type JsonOptions struct {
@@ -575,6 +586,8 @@ func (o JsonOptions) Validate() error {
 
 // -------------------------------------------------------------------
 
+var _ MultiValuer = (*FileOptions)(nil)
+
 type FileOptions struct {
 	MaxSelect int      `form:"maxSelect" json:"maxSelect"`
 	MaxSize   int      `form:"maxSize" json:"maxSize"` // in bytes
@@ -593,8 +606,16 @@ func (o FileOptions) Validate() error {
 	)
 }
 
+// IsMultiple implements MultiValuer interface and checks whether the
+// current field options support multiple values.
+func (o FileOptions) IsMultiple() bool {
+	return o.MaxSelect > 1
+}
+
 // -------------------------------------------------------------------
 
+var _ MultiValuer = (*RelationOptions)(nil)
+
 type RelationOptions struct {
 	// CollectionId is the id of the related collection.
 	CollectionId string `form:"collectionId" json:"collectionId"`
@@ -632,6 +653,12 @@ func (o RelationOptions) Validate() error {
 	)
 }
 
+// IsMultiple implements MultiValuer interface and checks whether the
+// current field options support multiple values.
+func (o RelationOptions) IsMultiple() bool {
+	return o.MaxSelect == nil || *o.MaxSelect > 1
+}
+
 // -------------------------------------------------------------------
 
 // Deprecated: Will be removed in v0.9+

models/schema/schema_field_test.go

@@ -1983,6 +1983,28 @@ func TestSelectOptionsValidate(t *testing.T) {
 	checkFieldOptionsScenarios(t, scenarios)
 }
 
+func TestSelectOptionsIsMultiple(t *testing.T) {
+	scenarios := []struct {
+		maxSelect int
+		expect    bool
+	}{
+		{-1, false},
+		{0, false},
+		{1, false},
+		{2, true},
+	}
+
+	for i, s := range scenarios {
+		opt := schema.SelectOptions{
+			MaxSelect: s.maxSelect,
+		}
+
+		if v := opt.IsMultiple(); v != s.expect {
+			t.Errorf("[%d] Expected %v, got %v", i, s.expect, v)
+		}
+	}
+}
+
 func TestJsonOptionsValidate(t *testing.T) {
 	scenarios := []fieldOptionsScenario{
 		{
@@ -2053,6 +2075,28 @@ func TestFileOptionsValidate(t *testing.T) {
 	checkFieldOptionsScenarios(t, scenarios)
 }
 
+func TestFileOptionsIsMultiple(t *testing.T) {
+	scenarios := []struct {
+		maxSelect int
+		expect    bool
+	}{
+		{-1, false},
+		{0, false},
+		{1, false},
+		{2, true},
+	}
+
+	for i, s := range scenarios {
+		opt := schema.FileOptions{
+			MaxSelect: s.maxSelect,
+		}
+
+		if v := opt.IsMultiple(); v != s.expect {
+			t.Errorf("[%d] Expected %v, got %v", i, s.expect, v)
+		}
+	}
+}
+
 func TestRelationOptionsValidate(t *testing.T) {
 	scenarios := []fieldOptionsScenario{
 		{
@@ -2088,3 +2132,26 @@ func TestRelationOptionsValidate(t *testing.T) {
 
 	checkFieldOptionsScenarios(t, scenarios)
 }
+
+func TestRelationOptionsIsMultiple(t *testing.T) {
+	scenarios := []struct {
+		maxSelect *int
+		expect    bool
+	}{
+		{nil, true},
+		{types.Pointer(-1), false},
+		{types.Pointer(0), false},
+		{types.Pointer(1), false},
+		{types.Pointer(2), true},
+	}
+
+	for i, s := range scenarios {
+		opt := schema.RelationOptions{
+			MaxSelect: s.maxSelect,
+		}
+
+		if v := opt.IsMultiple(); v != s.expect {
+			t.Errorf("[%d] Expected %v, got %v", i, s.expect, v)
+		}
+	}
+}