Add support for Update statements.

sqlbuilder/utils.go

@@ -1 +1,35 @@
 package sqlbuilder
+
+import "bytes"
+
+func serializeExpressionList(expressions []Expression, buf *bytes.Buffer) error {
+	for i, value := range expressions {
+		if i > 0 {
+			buf.WriteString(", ")
+		}
+
+		err := value.SerializeSql(buf)
+
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func serializeProjectionList(projections []Projection, buf *bytes.Buffer) error {
+	for i, value := range projections {
+		if i > 0 {
+			buf.WriteString(", ")
+		}
+
+		err := value.SerializeForProjection(buf)
+
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}