Removing Documents from a Collection with SODA for In-Database JavaScript
Removing documents from a collection is similar to replacing. The first step
is to perform a lookup operation, usually based on the document's key or by using a search
expression in SodaOperation.filter()
. The call to
SodaOperation.remove()
is a terminal operation, in other words the last
operation in the chain.
Example 8-16 Removing a Document from a Collection Using a Document Key
This example removes the document whose document key is "100"
.
export function removeByKey(searchKey){
// open MyCollection
const col = soda.openCollection("MyCollection");
if(col === null){
throw new Error("'MyCollection' does not exist");
}
// perform a lookup of the document about to be removed
// and ultimately remove it
const result = col
.find()
.key(searchKey)
.remove();
if(result.count === 0){
throw new Error(
`failed to delete a document with key ${searchKey}`
);
}
}
Example 8-17 Removing JSON Documents from a Collection Using a Filter
This example uses a filter to remove the JSON documents whose
department_id
is 70
. It then prints the number of
documents removed.
export function removeByFilter(){
// open the collection
const col = soda.openCollection("MyCollection");
if(col === null){
throw new Error("'MyCollection' does not exist");
}
// perform a lookup based on a filter expression and remove
// the documents matching the filter
const result = col
.find()
.filter({"_id": 100})
.remove();
console.log(`${result.count} documents deleted`);
}
Parent topic: Using SODA for In-Database JavaScript