Fix ToDBName (#1941)

Don't place '_' before number.

- NG: SHA256Hash -> sha_256_hash
- OK: SHA256Hash -> sha256_hash

utils.go

@@ -78,16 +78,18 @@ func ToDBName(name string) string {
 	}
 
 	var (
-		value                        = commonInitialismsReplacer.Replace(name)
-		buf                          = bytes.NewBufferString("")
-		lastCase, currCase, nextCase strCase
+		value                                    = commonInitialismsReplacer.Replace(name)
+		buf                                      = bytes.NewBufferString("")
+		lastCase, currCase, nextCase, nextNumber strCase
 	)
 
 	for i, v := range value[:len(value)-1] {
 		nextCase = strCase(value[i+1] >= 'A' && value[i+1] <= 'Z')
+		nextNumber = strCase(value[i+1] >= '0' && value[i+1] <= '9')
+
 		if i > 0 {
 			if currCase == upper {
-				if lastCase == upper && nextCase == upper {
+				if lastCase == upper && (nextCase == upper || nextNumber == upper) {
 					buf.WriteRune(v)
 				} else {
 					if value[i-1] != '_' && value[i+1] != '_' {
@@ -97,7 +99,7 @@ func ToDBName(name string) string {
 				}
 			} else {
 				buf.WriteRune(v)
-				if i == len(value)-2 && nextCase == upper {
+				if i == len(value)-2 && (nextCase == upper && nextNumber == lower) {
 					buf.WriteRune('_')
 				}
 			}

utils_test.go

@@ -15,6 +15,9 @@ func TestToDBNameGenerateFriendlyName(t *testing.T) {
 		"AbcAndJkl":                 "abc_and_jkl",
 		"EmployeeID":                "employee_id",
 		"SKU_ID":                    "sku_id",
+		"UTF8":                      "utf8",
+		"Level1":                    "level1",
+		"SHA256Hash":                "sha256_hash",
 		"FieldX":                    "field_x",
 		"HTTPAndSMTP":               "http_and_smtp",
 		"HTTPServerHandlerForURLID": "http_server_handler_for_url_id",