问题描述
我想使用 Java 一次将多行插入到 MySQL 表中.行数是动态的.过去我在做...
I want to insert multiple rows into a MySQL table at once using Java. The number of rows is dynamic. In the past I was doing...
for (String element : array) {
myStatement.setString(1, element[0]);
myStatement.setString(2, element[1]);
myStatement.executeUpdate();
}
我想优化它以使用 MySQL 支持的语法:
I'd like to optimize this to use the MySQL-supported syntax:
INSERT INTO table (col1, col2) VALUES ('val1', 'val2'), ('val1', 'val2')[, ...]
但是使用 PreparedStatement
我不知道有什么方法可以做到这一点,因为我事先不知道 array
将包含多少个元素.如果使用 PreparedStatement
无法实现,我还能怎么做(并且仍然转义数组中的值)?
but with a PreparedStatement
I don't know of any way to do this since I don't know beforehand how many elements array
will contain. If it's not possible with a PreparedStatement
, how else can I do it (and still escape the values in the array)?
推荐答案
您可以通过 PreparedStatement#addBatch()
并通过PreparedStatement#executeBatch()
.
You can create a batch by PreparedStatement#addBatch()
and execute it by PreparedStatement#executeBatch()
.
这是一个启动示例:
public void save(List<Entity> entities) throws SQLException {
try (
Connection connection = database.getConnection();
PreparedStatement statement = connection.prepareStatement(SQL_INSERT);
) {
int i = 0;
for (Entity entity : entities) {
statement.setString(1, entity.getSomeProperty());
// ...
statement.addBatch();
i++;
if (i % 1000 == 0 || i == entities.size()) {
statement.executeBatch(); // Execute every 1000 items.
}
}
}
}
它每 1000 个项目执行一次,因为某些 JDBC 驱动程序和/或数据库可能对批处理长度有限制.
It's executed every 1000 items because some JDBC drivers and/or DBs may have a limitation on batch length.
另见:
这篇关于Java:使用 PreparedStatement 将多行插入 MySQL的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!