Php和PDO-获取数据
有人能告诉我为什么以下不起作用:Php和PDO-获取数据,php,mysql,pdo,Php,Mysql,Pdo,有人能告诉我为什么以下不起作用: $result = $this->db->prepare("SELECT high,low FROM data where symbol=:symbol and date1 <= :date1 order by date1 desc LIMIT :limit1"); $result->bindParam(':symbol', $total_pairs, PDO::PARAM_STR); $result->bindPa
$result = $this->db->prepare("SELECT high,low FROM data where symbol=:symbol and date1 <= :date1 order by date1 desc LIMIT :limit1");
$result->bindParam(':symbol', $total_pairs, PDO::PARAM_STR);
$result->bindParam(':date1', $date1, PDO::PARAM_STR);
$result->bindParam(':limit1', $period, PDO::PARAM_INT);
$result->execute();
$data = $result->fetchAll(PDO::FETCH_ASSOC);
var_export($data["high"]);
我正在尝试获取这两列并获取数组中的结果 $data数组包含多个关联数组(每个返回的记录对应一个)。如果只需要结果集中一个数组中每个记录的高值和另一个数组中的低值,可以执行以下操作:
<?php
$high = array_column($data, 'high');
$low = array_column($data, 'low');
?>
它可以帮助您更好地理解。这段代码取自php.net网站为什么不尝试使用
var\u export($data)
查看您得到了什么?正如错误所说,没有称为high的索引$数据应该是一个数组,它包含的关联数组的数量与查询中获取的行的数量相同。它应该是$data[0][“high”]
。只需增加第一个索引。@OrlandoLeite,这没有帮助,因为你可以看到我已经在做了。我确实得到了一个关联数组,但仍然无法引用。非常感谢您的帮助。。。我以前从来不知道array\u column函数!!!工作得很有魅力。
<?php
$high = array_column($data, 'high');
$low = array_column($data, 'low');
?>
<?php
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();
/* Exercise PDOStatement::fetch styles */
print("PDO::FETCH_ASSOC: ");
print("Return next row as an array indexed by column name\n");
$result = $sth->fetch(PDO::FETCH_ASSOC);
print_r($result);
print("\n");
print("PDO::FETCH_BOTH: ");
print("Return next row as an array indexed by both column name and number\n");
$result = $sth->fetch(PDO::FETCH_BOTH);
print_r($result);
print("\n");
print("PDO::FETCH_LAZY: ");
print("Return next row as an anonymous object with column names as properties\n");
$result = $sth->fetch(PDO::FETCH_LAZY);
print_r($result);
print("\n");
print("PDO::FETCH_OBJ: ");
print("Return next row as an anonymous object with column names as properties\n");
$result = $sth->fetch(PDO::FETCH_OBJ);
print $result->name;
print("\n");
?>