Add check for zero or blank

zero/string.go

@@ -9,6 +9,7 @@ import (
 	"database/sql"
 	"encoding/json"
 	"fmt"
+	"strings"
 )
 
 // nullBytes is a JSON null literal
@@ -105,6 +106,11 @@ func (s String) IsZero() bool {
 	return !s.Valid || s.String == ""
 }
 
+// IsZero returns true for null empty strings or strings which consist only of blanks.
+func (s String) IsZeroOrBlank() bool {
+	return !s.Valid || strings.ReplaceAll(s.String, " ", "") == ""
+}
+
 // Equal returns true if both strings have the same value or are both either null or empty.
 func (s String) Equal(other String) bool {
 	return s.ValueOrZero() == other.ValueOrZero()

zero/string_test.go

@@ -145,6 +145,33 @@ func TestStringIsZero(t *testing.T) {
 	}
 }
 
+func TestStringIsZeroOrBlank(t *testing.T) {
+	str := StringFrom("test")
+	if str.IsZeroOrBlank() {
+		t.Errorf("IsZero() should be false")
+	}
+
+	null := StringFrom("")
+	if !null.IsZeroOrBlank() {
+		t.Errorf("IsZeroOrBlank() should be true")
+	}
+
+	empty := NewString("", true)
+	if !empty.IsZeroOrBlank() {
+		t.Errorf("IsZeroOrBlank() should be true")
+	}
+
+	nullBlank := StringFrom(" ")
+	if !nullBlank.IsZeroOrBlank() {
+		t.Errorf("IsZeroOrBlank() should be true")
+	}
+
+	emptyBlank := NewString(" ", true)
+	if !emptyBlank.IsZeroOrBlank() {
+		t.Errorf("IsZeroOrBlank() should be true")
+	}
+}
+
 func TestStringScan(t *testing.T) {
 	var str String
 	err := str.Scan("test")