正则表达式忽略MongoDB中的特定字符？
您可以将正则表达式与$not运算符一起使用，以忽略特定字符并显示其余字符。首先让我们创建一个包含文档的集合-
> db.regexDemo.insertOne({"CustomerId":"Customer#1234","CustomerName":"Chris"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cc7428f8f9e6ff3eb0ce436")
}
> db.regexDemo.insertOne({"CustomerId":"Customer5678","CustomerName":"Robert"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cc7429e8f9e6ff3eb0ce437")
}
> db.regexDemo.insertOne({"CustomerId":"Customer#777","CustomerName":"Carol"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cc742ae8f9e6ff3eb0ce438")
}
> db.regexDemo.insertOne({"CustomerId":"Customer777","CustomerName":"David"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cc742bc8f9e6ff3eb0ce439")
}以下是在find()方法的帮助下显示集合中所有文档的查询-
> db.regexDemo.find().pretty();
这将产生以下输出-
{
"_id" : ObjectId("5cc7428f8f9e6ff3eb0ce436"),
"CustomerId" : "Customer#1234",
"CustomerName" : "Chris"
}
{
"_id" : ObjectId("5cc7429e8f9e6ff3eb0ce437"),
"CustomerId" : "Customer5678",
"CustomerName" : "Robert"
}
{
"_id" : ObjectId("5cc742ae8f9e6ff3eb0ce438"),
"CustomerId" : "Customer#777",
"CustomerName" : "Carol"
}
{
"_id" : ObjectId("5cc742bc8f9e6ff3eb0ce439"),
"CustomerId" : "Customer777",
"CustomerName" : "David"
}情况1-这是避免在MongoDB中使用特定字符的查询。字符是#-
> db.regexDemo.find({CustomerId: /^[^#]*$/}).pretty();这将产生以下输出-
{
"_id" : ObjectId("5cc7429e8f9e6ff3eb0ce437"),
"CustomerId" : "Customer5678",
"CustomerName" : "Robert"
}
{
"_id" : ObjectId("5cc742bc8f9e6ff3eb0ce439"),
"CustomerId" : "Customer777",
"CustomerName" : "David"
}情况2–这是另一个查询，以避免在MongoDB中使用特定字符。字符是#-
> db.regexDemo.find({CustomerId: {$not: /#/}}).pretty();这将产生以下输出-
{
"_id" : ObjectId("5cc7429e8f9e6ff3eb0ce437"),
"CustomerId" : "Customer5678",
"CustomerName" : "Robert"
}
{
"_id" : ObjectId("5cc742bc8f9e6ff3eb0ce439"),
"CustomerId" : "Customer777",
"CustomerName" : "David"
}