allow schema field lookups to be case insensitive

go.mod

@@ -5,4 +5,11 @@ go 1.18
 require (
 	github.com/jinzhu/inflection v1.0.0
 	github.com/jinzhu/now v1.1.5
+	github.com/stretchr/testify v1.9.0
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,4 +1,14 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/jinzhu/inflection v1.0.0 h1:K317FqzuhWc8YvSVlFMCCUb36O/S9MCKRDI7QkRKD/E=
 github.com/jinzhu/inflection v1.0.0/go.mod h1:h+uFLlag+Qp1Va5pdKtLDYj+kHp5pxUVkryuEj+Srlc=
 github.com/jinzhu/now v1.1.5 h1:/o9tlHleP7gOFmsnYNz3RGnqzefHA47wQpKrrdTIwXQ=
 github.com/jinzhu/now v1.1.5/go.mod h1:d3SSVoowX0Lcu0IBviAWJpolVfI5UJVZZ7cO71lE/z8=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

schema/schema.go

@@ -77,9 +77,20 @@ func (schema Schema) LookUpField(name string) *Field {
 	if field, ok := schema.FieldsByDBName[name]; ok {
 		return field
 	}
+	for key, field := range schema.FieldsByDBName {
+		if strings.EqualFold(key, name) {
+			return field
+		}
+	}
 	if field, ok := schema.FieldsByName[name]; ok {
 		return field
 	}
+	for key, field := range schema.FieldsByName {
+		if strings.EqualFold(key, name) {
+			return field
+		}
+	}
+
 	return nil
 }
 
@@ -100,6 +111,11 @@ func (schema Schema) LookUpFieldByBindName(bindNames []string, name string) *Fie
 		if field, ok := schema.FieldsByBindName[find]; ok {
 			return field
 		}
+		for key, field := range schema.FieldsByBindName {
+			if strings.EqualFold(key, find) {
+				return field
+			}
+		}
 	}
 	return nil
 }

schema/schema_test.go

@@ -5,6 +5,7 @@ import (
 	"sync"
 	"testing"
 
+	"github.com/stretchr/testify/assert"
 	"gorm.io/gorm"
 	"gorm.io/gorm/schema"
 	"gorm.io/gorm/utils/tests"
@@ -334,3 +335,46 @@ func TestCompositePrimaryKeyWithAutoIncrement(t *testing.T) {
 		t.Fatalf("PrioritizedPrimaryField of non autoincrement composite key should be nil")
 	}
 }
+
+func TestLookupField(t *testing.T) {
+	type Product struct {
+		ProductID uint   `gorm:"primaryKey;autoIncrement"`
+		Code      string `gorm:"column:product_code"`
+		Name      string
+	}
+	product, err := schema.Parse(&Product{}, &sync.Map{}, schema.NamingStrategy{})
+	if err != nil {
+		t.Fatalf("failed to parse product struct with composite primary key, got error %v", err)
+	}
+	field := product.LookUpField("ProductID")
+	assert.NotNil(t, field)
+	field = product.LookUpField("productid")
+	assert.NotNil(t, field)
+	field = product.LookUpField("product_code")
+	assert.NotNil(t, field)
+	field = product.LookUpField("PRODUCT_CODE")
+	assert.NotNil(t, field)
+}
+
+func TestLookupFieldByBindName(t *testing.T) {
+	type Product struct {
+		ID uint `gorm:"primaryKey;autoIncrement"`
+	}
+	type Sellable struct {
+		Name    string
+		Product Product `gorm:"embedded;embeddedPrefix:product_"`
+	}
+
+	product, err := schema.Parse(&Sellable{}, &sync.Map{}, schema.NamingStrategy{})
+	if err != nil {
+		t.Fatalf("failed to parse Sellable struct with composite primary key, got error %v", err)
+	}
+	field := product.LookUpFieldByBindName([]string{"Product", "ID"}, "ID")
+	assert.NotNil(t, field)
+	field = product.LookUpFieldByBindName([]string{"Product", "ID"}, "id")
+	assert.NotNil(t, field)
+	field = product.LookUpFieldByBindName([]string{"Product", "id"}, "id")
+	assert.NotNil(t, field)
+	field = product.LookUpFieldByBindName([]string{"product", "id"}, "id")
+	assert.NotNil(t, field)
+}