MongoDB $regex使用运算符i或I不区分大小写的搜索
为此，您需要使用不区分大小写的(i)。让我们创建一个包含文档的集合-
> db.demo759.insertOne({SubjectName:"MySQL"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5eb02ba95637cd592b2a4ae7")
}
> db.demo759.insertOne({SubjectName:"MongoDB"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5eb02baa5637cd592b2a4ae8")
}
> db.demo759.insertOne({SubjectName:"mongodb"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5eb02baf5637cd592b2a4ae9")
}
> db.demo759.insertOne({SubjectName:"MONGODB"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5eb02bb85637cd592b2a4aea")
}在find()方法的帮助下显示集合中的所有文档-
> db.demo759.find();
这将产生以下输出-
{ "_id" : ObjectId("5eb02ba95637cd592b2a4ae7"), "SubjectName" : "MySQL" }
{ "_id" : ObjectId("5eb02baa5637cd592b2a4ae8"), "SubjectName" : "MongoDB" }
{ "_id" : ObjectId("5eb02baf5637cd592b2a4ae9"), "SubjectName" : "mongodb" }
{ "_id" : ObjectId("5eb02bb85637cd592b2a4aea"), "SubjectName" : "MONGODB" }以下是实现MongoDB正则表达式运算符的查询-
> db.demo759.find({"SubjectName":{$regex:/mongodb/i}});这将产生以下输出-
{ "_id" : ObjectId("5eb02baa5637cd592b2a4ae8"), "SubjectName" : "MongoDB" }
{ "_id" : ObjectId("5eb02baf5637cd592b2a4ae9"), "SubjectName" : "mongodb" }
{ "_id" : ObjectId("5eb02bb85637cd592b2a4aea"), "SubjectName" : "MONGODB" }