新增 NOT LIKE、IS NULL 和 IS NOT NULL 操作符，并更新文档示例

test/example.ts

@@ -73,3 +73,24 @@ console.log(filter(products, "WHERE name LIKE '%Phone%'"));
 
 console.log('\n=== 第二个字符任意的产品 (A_pple%) ===');
 console.log(filter(products, "WHERE name LIKE 'A_pple%'"));
+
+console.log('\n=== NOT LIKE 测试 ===');
+console.log('\n=== 不包含 Apple 的产品 (NOT LIKE %Apple%) ===');
+console.log(filter(products, "WHERE name NOT LIKE '%Apple%'"));
+
+console.log('\n=== IS NULL 和 IS NOT NULL 测试 ===');
+const usersWithNull = [
+  { name: 'Alice', email: 'alice@example.com', age: 25 },
+  { name: 'Bob', email: null, age: 30 },
+  { name: 'Charlie', email: undefined, age: 35 },
+  { name: 'Diana', email: 'diana@example.com', age: null }
+];
+
+console.log('\n=== Email 为 NULL 或 undefined 的用户 ===');
+console.log(filter(usersWithNull, "WHERE email IS NULL"));
+
+console.log('\n=== Email 不为 NULL 且不为 undefined 的用户 ===');
+console.log(filter(usersWithNull, "WHERE email IS NOT NULL"));
+
+console.log('\n=== Age 不为 NULL 且不为 undefined 的用户 ===');
+console.log(filter(usersWithNull, "WHERE age IS NOT NULL"));