Question

我正在使用PostgreSQL来获取数据，我想将其插入MySQL。我有一个PHP脚本，它允许我获取数据，检查重复，然后将其插入MySQL DB。问题是，它不是仅插入非现有数据，而是插入一个随机行，而不插入任何其他行。

$check_for_episode = mysqli_query($conn, "SELECT DISTINCT house_number,number FROM episode WHERE house_number LIKE '".$house_number."' AND number = ".$episode_id_pg." LIMIT 1");

  if (mysqli_fetch_array($check_for_episode)){

  }else{
     $insert_episode = mysqli_query($conn, "INSERT INTO episode(".$episode_col.")VALUES('".$episode_values."')");

  }

变量$episode_col和$episode_values通过implode从名为$episode的数组中获取数据：

$episode_col = implode(", ", array_keys($episode));
$episode_values = implode("', '", array_values($episode));

Answer 1

这是你的代码。

IF语句用于比较，你的语句只是获取数组，而IF语句中没有任何条件。您需要修复语句以获取列及其各自的值。

$check_for_episode = mysqli_query($conn, "SELECT DISTINCT house_number,number FROM episode WHERE house_number LIKE '".$house_number."' AND number = ".$episode_id_pg." LIMIT 1");

  if (mysqli_fetch_array($check_for_episode)){

  }else{
     $insert_episode = mysqli_query($conn, "INSERT INTO episode(".$episode_col.")VALUES('".$episode_values."')");

  }

您也可以尝试使用WHERE EXISTS或WHERE NOT EXISTS。

SELECT DISTINCT column1 FROM table1
  WHERE EXISTS (SELECT * FROM table2
                WHERE table2.column1 = table1.column1);

SELECT DISTINCT column1 FROM table1
  WHERE NOT EXISTS (SELECT * FROM table2
                    WHERE table2.column1 = table1.column1);

了解更多信息：https://dev.mysql.com/doc/refman/5.7/en/exists-and-not-exists-subqueries.html

插入如果不存在MySQL

1 个答案: