java jdbc批量更新sql怎么写
时间: 2023-06-04 19:04:37 浏览: 99
你好,关于你的问题,可以使用PreparedStatement和addBatch()方法来批量更新SQL语句。以下是示例代码:
try {
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "password");
PreparedStatement ps = conn.prepareStatement("UPDATE user SET status = ? WHERE id = ?");
for (User u : userList) {
ps.setString(1, u.getStatus());
ps.setInt(2, u.getId());
ps.addBatch();
}
ps.executeBatch();
} catch (SQLException e) {
e.printStackTrace();
}
相关问题
java jdbc批量查询 传入list查询
可以使用Java的JDBC批处理来批量查询,其中可以使用PreparedStatement的setObject方法来设置参数,从而实现传入List进行查询。下面是一个示例代码:
```java
List<String> idList = Arrays.asList("id1", "id2", "id3");
String sql = "SELECT * FROM table WHERE id IN (";
for (int i = 0; i < idList.size(); i++) {
sql += "?";
if (i < idList.size() - 1) {
sql += ",";
} else {
sql += ")";
}
}
PreparedStatement ps = conn.prepareStatement(sql);
for (int i = 0; i < idList.size(); i++) {
ps.setObject(i + 1, idList.get(i));
}
ResultSet rs = ps.executeQuery();
```
在这个示例中,首先将需要查询的id列表存储在List中,然后创建SQL语句,将List中的每个id都转换为一个占位符,并使用PreparedStatement的setObject方法将List中的每个id传递给占位符。最后执行查询并获取结果集。
mysql jdbc驱动 批量更新_jdbc批量插入,删除,更新
JDBC提供了批量操作的支持,可以通过一次数据库连接,执行多个相似的数据库操作,从而提高数据库操作的效率。下面是JDBC批量操作的示例代码:
1. 批量插入数据:
```java
Connection conn = DriverManager.getConnection(url, user, password);
Statement stmt = conn.createStatement();
String sql = "INSERT INTO student (name, age, gender) VALUES ('Tom', 18, 'M')";
stmt.addBatch(sql);
sql = "INSERT INTO student (name, age, gender) VALUES ('Lucy', 20, 'F')";
stmt.addBatch(sql);
sql = "INSERT INTO student (name, age, gender) VALUES ('Jack', 19, 'M')";
stmt.addBatch(sql);
int[] result = stmt.executeBatch(); // 执行批量插入
```
2. 批量更新数据:
```java
Connection conn = DriverManager.getConnection(url, user, password);
Statement stmt = conn.createStatement();
String sql = "UPDATE student SET age = 20 WHERE gender = 'M'";
stmt.addBatch(sql);
sql = "UPDATE student SET age = 22 WHERE gender = 'F'";
stmt.addBatch(sql);
int[] result = stmt.executeBatch(); // 执行批量更新
```
3. 批量删除数据:
```java
Connection conn = DriverManager.getConnection(url, user, password);
Statement stmt = conn.createStatement();
String sql = "DELETE FROM student WHERE age < 18";
stmt.addBatch(sql);
sql = "DELETE FROM student WHERE age > 22";
stmt.addBatch(sql);
int[] result = stmt.executeBatch(); // 执行批量删除
```
需要注意的是,批量操作的语句必须是相同的类型,例如,不能混合插入和更新操作。同时,批量操作也可能会受到数据库的限制,例如,数据库有可能限制一次批量操作的数量,需要根据实际情况进行调整。
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