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MongoDB $not用法及代碼示例

MongoDB 提供了多種邏輯查詢操作符。 $not 運算符就是這些運算符之一。它類似於編程中的邏輯非運算符。 $not 運算符用於對指定的表達式執行邏輯 "NOT operation"。您可以將它與任何其他查詢表達式一起使用,例如等於 ($eq)、大於 ($gt) 或小於 ($lt)。

$not 運算符可以與正則表達式一起使用。它僅選擇或檢索那些與給定運算符表達式不匹配的文檔。用戶可以根據需要在 find()、update() 等方法中使用該運算符。

用法:

{ field:{ $not:{ operator-expression } } }

例子:

在以下示例中,我們正在使用:

Database:JavaTpoint
Collection:student
Document:Six documents that contain the details of the students
[
        {
                "std_name":"Jack",
                "sex":"Male",
                "class":"VI",
                "age":11,
                "Total_marks":303
                "Result":"Pass"
        },
        {
                "std_name":"Jenny",
                "sex":"Female",
                "class":"VI",
                "age":13,
                "Total_marks":800
                "Result":"Pass"
        },
        {
                "std_name":"Thomas",
                "sex":"Male",
                "class":"V",
                "age":11,
                " Total_marks":200
                " Result":"Fail"
        },
        {
                "std_name":"Lassy",
                "sex":"Female",
                "class":"X",
                "age":17,
                "Total_marks":550
                "Result":"Pass"
        },
        {
                "std_name":"Mia",
                "sex":"Female",
                "class":"X",
                "age":19,
                " Total_marks":350
                "Result":"Pass"
       },
       {
                "std_name":"Mike,
                "sex":"Male",
                "class":"V",
                "age":16,
                "Total_marks":700
                "Result":"Pass"
        }
]

示例 1:MongoDB 邏輯 $not 運算符(至少):

在這個例子中,我們隻檢索 "Total_marks" 至少為 400 的學生的數據。

db.student.find({"Total_marks":{$not:{$lt:400}}}).pretty()

SQL等效命令:

SELECT * 
FROM student 
WHERE Total_marks >= 400;

輸出:

>db.student.find({"Total_marks":{$not:{$lt:400}}}).pretty()
{      
                "_Id":ObjectId("4565d4cd85d4f1vf6345612"),    
                "std_name":"Jenny",
                "sex":"Female",
                "class":"VI",
                "age":13,
                "Total_marks":800
                "Result":"Pass"
}
{
                "_Id":ObjectId("4565d4cd85d4f1vf6345665"),
                "std_name":"Lassy",
                "sex":"Female",
                "class":"X",
                "age":17,
                "Total_marks":550
                "Result":"Pass"
}
{
                "_Id":ObjectId("4565d4cd85d4f1vf6345756"),
                "std_name":"Mike,
                "sex":"Male",
                "class":"V",
                "age":16,
                "Total_marks":700
                "Result":"Pass"
}

示例 2:MongoDB 邏輯 $not 運算符(不大於):

在這個例子中,我們隻檢索 "age" 不大於 12 的學生的數據。

db.student.find({"age":{$not:{$gt:12}}}).pretty()

輸出:

>db.student.find({"age":{$not:{$gt:12}}}).pretty()
{
                "_Id":ObjectId("4565d4cd85d4f545ffg43df7"),
                "std_name":"Jack",
                "sex":"Male",
                "class":"VI",
                "age":11,
                "Total_marks":303
                "Result":"Pass"
} 
{
                "_Id":ObjectId("4565d4cd85d4f545ffg43df7"),
                "std_name":"Thomas",
                "sex":"Male",
                "class":"V",
                "age":11,
                " Total_marks":200
                " Result":"Fail"
}

示例 3:MongoDB 邏輯 $not 運算符(不等於):

在這個例子中,我們隻檢索 "age" 不等於 11 的學生的數據。

db.student.find({"age":{$not:{$eq:11}}}).pretty()

輸出:

>db.student.find({"age":{$not:{$eq:11}}}).pretty()
{
               "_Id":ObjectId("4565d4cd85d45d4dgf1fd5f4"),
               "std_name":"Jenny",
                "sex":"Female",
                "class":"VI",
                "age":13,
                "Total_marks":800
                "Result":"Pass"
}
{
                "_Id":ObjectId("4565d4cd85d45d4dgf1fd55s"),
                "std_name":"Lassy",
                "sex":"Female",
                "class":"X",
                "age":17,
                "Total_marks":550
                "Result":"Pass"
}
{
                "_Id":ObjectId("4565d4cd85d45d4d85331531"),
                "std_name":"Mia",
                "sex":"Female",
                "class":"X",
                "age":19,
                " Total_marks":350
                "Result":"Pass"
}
{
                "_Id":ObjectId("4565d4cd85d45d4456c53154"),
                "std_name":"Mike,
                "sex":"Male",
                "class":"V",
                "age":16,
                "Total_marks":700
                "Result":"Pass"
}	




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