MongoDB 在尝试插入整数时插入浮点数
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MongoDB inserts float when trying to insert integer
提问by daydreamer
> db.data.update({'name': 'zero'}, {'$set': {'value': 0}})
> db.data.findOne({'name': 'zero})
{'name': 'zero', 'value': 0.0}
How do I get Mongo to insert an integer?
如何让 Mongo 插入一个整数？
Thank you
谢谢
回答by Bernie Hackett
db.data.update({'name': 'zero'}, {'$set': {'value': NumberInt(0)}})
You can also use NumberLong.
您也可以使用 NumberLong。
回答by Grid Trekkor
A slightly simpler syntax (in Robomongo at least) worked for me:
一个稍微简单的语法（至少在 Robomongo 中）对我有用：
db.database.save({ Year : NumberInt(2015) });
回答by Ethan. Zhang
If the value type is already double, then update the value with $set command can not change the value type double to int when using NumberInt() or NumberLong() function. So, to Change the value type, it must update the whole record.
如果值类型已经是double，那么在使用NumberInt()或NumberLong()函数时，用$set命令更新值不能将值类型double改为int。因此，要更改值类型，它必须更新整个记录。
var re = db.data.find({"name": "zero"})
re['value']=NumberInt(0)
db.data.update({"name": "zero"}, re)
回答by Christian Horsdal
Well, it's JavaScript, so what you have in 'value' is a Number, which can be an integer or a float. But there's not really a difference in JavaScript. From Learning JavaScript:
嗯，它是 JavaScript，所以你在 'value' 中拥有的是一个数字，它可以是一个整数或一个浮点数。但是在 JavaScript 中并没有真正的区别。从学习 JavaScript：
The Number Data Type
Number data types in JavaScript are floating-point numbers, but they may or may not have a fractional component. If they don't have a decimal point or fractional component, they're treated as integers—base-10 whole numbers in a range of –253to 253.
数字数据类型
JavaScript 中的数字数据类型是浮点数，但它们可能有也可能没有小数部分。如果它们没有小数点或小数部分，它们将被视为整数——范围为 –2 53到 2 53 的以10 为底的整数。
