MongoDB has a Date BSON type that allows you to store dates as dates.
You can also store dates as strings, if that’s what you need.
Taking it a step further, you can also convert a Date to a string.
This article presents three ways to convert a Date to a string in MongoDB.
Continue readingIf you get the “$pullAll requires an array argument but was given a double” error in MongoDB, it’s because you didn’t provide an array as the value to replace.
Continue readingIf you have documents that store dates as Date objects, but you want to return them in a different format, you can use the $dateToString aggregate pipeline operator.
For example, you might want a date to be returned in mm/dd/yyyy format instead of the long ISODate() format that includes minutes, seconds, milliseconds, etc
The $dateToString operator converts the Date object to a string, and optionally allows you to specify a format for the resulting output.
If you’re getting a “longitude/latitude is out of bounds” error when trying to create a 2dsphere index in MongoDB, it could be due to your longitude and latitude coordinates being in the wrong order.
Continue readingFrom MongoDB 4.4, it’s possible to hide an index from the query planner. This allows you to evaluate the potential impact of dropping an index without actually dropping the index.
You can use the getIndexes() method to check whether or not an index is hidden. If an index is hidden, that index will display a hidden field as having a value of true (i.e. "hidden" : true).
Starting from MongoDB 4.4, we can now hide indexes from the query plan. This enables us to evaluate the potential impact of dropping an index without actually dropping the index.
If hiding it has a negative impact, we can unhide the index. This saves us from having to drop the index, then recreate it again.
Below are 3 ways to hide an index in MongoDB.
Continue readingDistinct values are those values with redundant duplicates removed. In other words, distinct values are unique values.
In MongoDB there are a few ways we can return distinct values in a query. This article presents 3 ways to return distinct values in the mongo shell.
Continue readingMongoDB provides several ways to drop an index or indexes.
To drop a single index, you can use the dropIndex() method.
To drop multiple indexes, you can use either the dropIndexes() method or the dropIndexes administration command.
In MongoDB, the cursor.sort() method specifies the order in which the query returns matching documents.
The sort() method accepts a document that specifies the field to sort, and the sort order. The sort order can be either 1 for ascending or -1 for descending.
You can also specify { $meta: "textScore" } when doing $text searches, in order to sort by the computed textScore metadata in descending order.
In MongoDB, the $orderBy query modifier sorts the results of a query in ascending or descending order.
$orderBy accepts a document that specifies the field to sort, and the sort order. The sort order can be either 1 for ascending or -1 for descending.
$orderBy has been deprecated in the mongo shell since v3.2. Use the cursor.sort() method instead.