From 563d9b588ac212e2795248125ba87af97aab10b3 Mon Sep 17 00:00:00 2001
From: mohammad ali ashraf <ranaaliashraf12@gmail.com>
Date: Sun, 21 May 2023 01:46:27 +0500
Subject: [PATCH] max identifier length changed to 63

---
 gorm.go                     |  2 +-
 schema/naming.go            | 17 +++++++++++------
 schema/naming_test.go       |  6 +++---
 schema/relationship_test.go |  4 ++--
 4 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/gorm.go b/gorm.go
index 07a913fc..32c7cef4 100644
--- a/gorm.go
+++ b/gorm.go
@@ -146,7 +146,7 @@ func Open(dialector Dialector, opts ...Option) (db *DB, err error) {
 	}
 
 	if config.NamingStrategy == nil {
-		config.NamingStrategy = schema.NamingStrategy{}
+		config.NamingStrategy = schema.NamingStrategy{IdentifierMaxLength: 63}
 	}
 
 	if config.Logger == nil {
diff --git a/schema/naming.go b/schema/naming.go
index a258beed..37b94980 100644
--- a/schema/naming.go
+++ b/schema/naming.go
@@ -28,10 +28,11 @@ type Replacer interface {
 
 // NamingStrategy tables, columns naming strategy
 type NamingStrategy struct {
-	TablePrefix   string
-	SingularTable bool
-	NameReplacer  Replacer
-	NoLowerCase   bool
+	TablePrefix         string
+	SingularTable       bool
+	NameReplacer        Replacer
+	NoLowerCase         bool
+	IdentifierMaxLength int
 }
 
 // TableName convert string to table name
@@ -89,12 +90,16 @@ func (ns NamingStrategy) formatName(prefix, table, name string) string {
 		prefix, table, name,
 	}, "_"), ".", "_")
 
-	if utf8.RuneCountInString(formattedName) > 64 {
+	if ns.IdentifierMaxLength == 0 {
+		ns.IdentifierMaxLength = 63
+	}
+
+	if utf8.RuneCountInString(formattedName) > ns.IdentifierMaxLength {
 		h := sha1.New()
 		h.Write([]byte(formattedName))
 		bs := h.Sum(nil)
 
-		formattedName = formattedName[0:56] + hex.EncodeToString(bs)[:8]
+		formattedName = formattedName[0:ns.IdentifierMaxLength-8] + hex.EncodeToString(bs)[:8]
 	}
 	return formattedName
 }
diff --git a/schema/naming_test.go b/schema/naming_test.go
index 3f598c33..9ce8f099 100644
--- a/schema/naming_test.go
+++ b/schema/naming_test.go
@@ -189,11 +189,11 @@ func TestCustomReplacerWithNoLowerCase(t *testing.T) {
 	}
 }
 
-func TestFormatNameWithStringLongerThan64Characters(t *testing.T) {
-	ns := NamingStrategy{}
+func TestFormatNameWithStringLongerThan63Characters(t *testing.T) {
+	ns := NamingStrategy{IdentifierMaxLength: 63}
 
 	formattedName := ns.formatName("prefix", "table", "thisIsAVeryVeryVeryVeryVeryVeryVeryVeryVeryLongString")
-	if formattedName != "prefix_table_thisIsAVeryVeryVeryVeryVeryVeryVeryVeryVery180f2c67" {
+	if formattedName != "prefix_table_thisIsAVeryVeryVeryVeryVeryVeryVeryVeryVer180f2c67" {
 		t.Errorf("invalid formatted name generated, got %v", formattedName)
 	}
 }
diff --git a/schema/relationship_test.go b/schema/relationship_test.go
index 732f6f75..de5fa044 100644
--- a/schema/relationship_test.go
+++ b/schema/relationship_test.go
@@ -768,13 +768,13 @@ func TestParseConstraintNameWithSchemaQualifiedLongTableName(t *testing.T) {
 	s, err := schema.Parse(
 		&Book{},
 		&sync.Map{},
-		schema.NamingStrategy{},
+		schema.NamingStrategy{IdentifierMaxLength: 63},
 	)
 	if err != nil {
 		t.Fatalf("Failed to parse schema")
 	}
 
-	expectedConstraintName := "fk_my_schema_a_very_very_very_very_very_very_very_very_l4db13eec"
+	expectedConstraintName := "fk_my_schema_a_very_very_very_very_very_very_very_very_4db13eec"
 	constraint := s.Relationships.Relations["Author"].ParseConstraint()
 
 	if constraint.Name != expectedConstraintName {