mysqli bind_param中的NULL类型是什么? [英] What is the type of NULL in mysqli bind_param?

问题描述

我正在尝试将参数绑定到INSERT INTO MySQLi准备好的语句中(如果该变量存在)，否则插入null.然后我知道

I am trying to bind params to a INSERT INTO MySQLi prepared statement if that variable exists, otherwise insert null.Then i know

type    variable
i   corresponding variable has type integer
d   corresponding variable has type double
s   corresponding variable has type string
b   corresponding variable is a blob and will be sent in packets

但是当我插入一个变量= null时，如何定义变量的类型?还是我应该定义类型为"?

but when i insert a variable = null,how i define the type of the variable? Or should i define the type is ''?

推荐答案

您不需要将null强制转换为特定的数据类型-Mysqli将处理传递给任何可接受的数据类型的null值，因此只需使用每种类型如果您要传递非null值，则该字段将具有.

You do not need to cast null to a particular data type - Mysqli will handle null values passed to any of the accepted data types, so just use the type each field would have had if you were passing non-null values.

$intVar = null;
$doubleVar = null;
$stringVar = null;
$blobVar = null;

$insert_data->bind_param('idsb', $intVar, $doubleVar, $stringVar, $blobVar);

所有这些都是有效的，并且将被Mysqli接受.

All of these are valid and will be accepted by Mysqli.

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