java - 循环中的PreparedStatement，如何使用

Question

我正在尝试存储在 ITEM 表中创建的所有项目，我想知道是否可以做到这一点:

    PreparedStatement stm = null;
    //String sql = "INSERT INTO ITEM (ID, TYPE, TITEL, UITGELEEND) VALUES ('%s', '%s', '%s', %b)";

    try {
        stm = db.prepareStatement("INSERT INTO ITEM (ID, TYPE, TITEL, UITGELEEND) VALUES (?, ?, ?, ?)");

        for (int n = 0; n < ItemLijst.getItems().size(); n++) {
            Item huidigItem = ItemLijst.getItemObvIdx(n);

            stm.setString(1, huidigItem.getID().toString());
            stm.setString(2, huidigItem.getType().toString());
            stm.setString(3, huidigItem.getTitel());
            stm.setString(4, String.valueOf(huidigItem.isUitgeleend()));
        }
        stm.executeUpdate();
        stm.close();
    } catch (SQLException e) {
        e.printStackTrace();
    }

或者我需要在循环中包含 executeUpdate() 吗？那么PreparedStatement 呢？或者我需要执行 executeBatch() 吗？

Answer 1

在 for 循环内运行查询并不是最佳实践。最好使用批量更新，如下所示:

stm = db.prepareStatement("INSERT INTO ITEM (ID, TYPE, TITEL, UITGELEEND) VALUES (?, ?, ?, ?)");
db.setAutoCommit(false);  
for (int n = 0; n < ItemLijst.getItems().size(); n++) {
     Item huidigItem = ItemLijst.getItemObvIdx(n);
     stm.setString(1, huidigItem.getID().toString());
     stm.setString(2, huidigItem.getType().toString());
     stm.setString(3, huidigItem.getTitel());
     stm.setString(4,String.valueOf(huidigItem.isUitgeleend()));
     stm.addBatch();
     }
stm.executeBatch();
db.commit();