Question

让我们说我的表名为group with groups：

+----+---------+------+-------+
| id | user_id | name | color |
+----+---------+------+-------+
|  1 |       1 | foo  | green |
|  2 |       1 | bar  | red   |
|  3 |       1 | baz  |       |
|  4 |       2 | baz  | grey  |
|  5 |       3 | foo  | blue  |
|  6 |       3 | baz  |       |
|  7 |       4 | baz  | brown |
|  8 |       4 | foo  |       |
|  9 |       4 | qux  | black |
+----+---------+------+-------+

我要读取一个csv文件并将其转换为这样的数据数组：

[
    [
        'user_id'   => 2,
        'name'      => 'foo'
    ],
    [
        'user_id'   => 2,
        'name'      => 'bar'
    ],
    [
        'user_id'   => 2,
        'name'      => 'baz'
    ],
    [
        'user_id'   => 2,
        'name'      => 'qux'
    ],
    [
        'user_id'   => 2,
        'name'      => 'tux'
    ],
]

并仅将新数据插入数据库，并跳过数据库中已存在的数据，在此示例中为用户2的组baz。

在Eloquent中有一些有用的方法，如firstOrCreate()或findOrNew()似乎是我需要的，但这些方法只适用于一条记录，如果我使用它们，我应该按文件运行它们线。

while($line = $this->decoder->decode($this->file) {
    $row = Group::firstOrCreate($line);
}

运行较少的查询是否有更好的解决方案？

Answer 1

使用INSERT ... ON DUPLICATE KEY UPDATE

INSERT INTO table (user_id,name) VALUES(1, "test") ON DUPLICATE KEY UPDATE name=VALUES(name)

对于Laravel检查this question

Answer 2

您可以直接将文件加载到表中，并忽略重复的条目。您所需要的只是列上的唯一索引，它不应该有重复项。然后你做

LOAD DATA INFILE 'file_name.csv'
IGNORE
INTO TABLE tbl_name
FIELDS TERMINATED BY ','
OPTIONALLY ENCLOSED BY '"'
(user_id, @var)
SET name = do_some_voodoo(@var);

就是这样。阅读有关此命令的更多信息here。

<强>测试

/*sample data*/
shell> cat test.csv
Name|Value
Anna|hello
Ben |Test
East|whatever
Anna|This line should be ignored
Bob |

/*creating destination table in database*/
mysql> create table phpload(a varchar(50) primary key, b varchar(50));
Query OK, 0 rows affected (0.03 sec)

/*Test script*/
<?php
// Create connection
$con=mysqli_connect("localhost","root","r00t","playground");

// Check connection
if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

$sql = "LOAD DATA LOCAL INFILE '/home/developer/test.csv' IGNORE INTO TABLE phpload FIELDS TERMINATED BY '|' (a, @b) SET b = UPPER(@b);";

$result = mysqli_query($con, $sql) or die(mysqli_error());

mysqli_close($con);
?>

/*executing*/
shell> php test.php

mysql> select * from phpload;
+------+----------+
| a    | b        |
+------+----------+
| Name | VALUE    |
| Anna | HELLO    |
| Ben  | TEST     |
| East | WHATEVER |
| Bob  |          |
+------+----------+
5 rows in set (0.00 sec)

绝对正常。

laravel在插入之前检查记录存在，有效的方法

2 个答案: