用嵌套的方式改写代码SELECT readerName FROM tb_reader WHERE NOT EXISTS (SELECT * FROM tb_booklend WHERE bookCode = '11' AND tb_reader.readerId = readerId);
时间: 2024-03-23 19:42:34 浏览: 10
以下是使用嵌套的方式改写的代码:
```
SELECT readerName
FROM tb_reader
WHERE readerId NOT IN (SELECT readerId FROM tb_booklend WHERE bookCode = '11');
```
这样就用嵌套的方式将原始代码改写了。
相关问题
用连接的方式改写代码SELECT readerName FROM tb_reader WHERE NOT EXISTS (SELECT * FROM tb_booklend WHERE bookCode = '11' AND tb_reader.readerId = readerId);
以下是使用连接的方式改写的代码:
```
SELECT readerName
FROM tb_reader
LEFT JOIN tb_booklend ON tb_reader.readerId = tb_booklend.readerId AND tb_booklend.bookCode = '11'
WHERE tb_booklend.readerId IS NULL;
```
这样就用连接的方式将原始代码改写了。
SELECT readerName FROM tb_reader WHERE EXISTS (SELECT * FROM tb_booklend WHERE bookCode = '11' AND tb_reader.readerId = readerId); 用嵌套的方式改写代码
以下是使用嵌套的方式改写的代码:
```
SELECT readerName
FROM tb_reader
WHERE readerId IN (SELECT readerId FROM tb_booklend WHERE bookCode = '11');
```
这样就用嵌套的方式将原始代码改写了。