是否可以使用 spring-data-mongo 1.10 创建 Mongo 视图？

Question

I have a simple requirement to be able to create a Mongo view from my Java app. We're using the 3.4 Mongo driver and spring-data-mongo 1.10.2. The Mongo docs for db.createCollection indicate you create a view by including viewOn in the options, but the CollectionOptions class that is used by mongoTemplate.createCollection doesn't have this property.

I've dug through source code up to sdm version 2.2 and still don't see it supported. How can I create a view?

Answer 1

I was able to get this working. Below is the method:

private void createView(BaseEntity model, String viewName, String viewDefinition) {
    // Get the model's @Document annotation so we can determine its collection
    Document doc = model.getClass().getAnnotation(Document.class);
    Assert.notNull(doc, "Error - @Document annotation is null for model class: " + model.getClass().getSimpleName());

    // Attempt to create the view
    CommandResult result = mongoTemplate.executeCommand("{" +
        "create: '" + viewName + "', " +
        "viewOn: '" + doc.collection() + "', " +
        "pipeline: [{$match: " + viewDefinition + "}]" +
    "}");

    if(result.ok()) {
        LOGGER.info("Successfully created view '{}' on collection '{}'", viewName, doc.collection());
    }
    else {
        throw new ViewCreationBeanException(
            "Failed to create view '" + viewName + "' on collection '" + doc.collection() + "' - " + result.getErrorMessage(),
            result.getException()
        );
    }
}

model is the Java class with the @Document annotation that specifies the mongo collection. What I was doing here was creating a view on a model based on its underlying collection. viewDefinition are the view constraints, a String such as: "{deleted: {$ne: true}}" .