在spring mongo db查询中指定多个条件 [英] Specify multiple criteria's in spring mongo db query
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问题描述
我正在遍历键/值对列表并为每个键/值执行查找.我可以在sql中创建一个单一的查询文档作为一种联合,这样就只有一个数据库调用.
I am iterating over a list of key/value pairs and executing find for each key/value. Can I create a single query document to be kind of union in sql, So that there will be only one database call.
List<User> userList = new ArrayList<User>();
for (Map accounts:attributes) {
Query query = new Query();
List<Criteria> andCriteriaList = new ArrayList<Criteria>();
accounts.forEach((key, value) -> {
Criteria criteria = Criteria.where((String) key).is(value);
andCriteriaList.add(criteria);
});
query.addCriteria(new Criteria().andOperator(andCriteriaList.toArray(new Criteria[andCriteriaList.size()])));
if (mongoTemplate.exists(query, User.class)) {
userList.add((User)mongoTemplate.find(query, User.class));
//System.out.println(mongoTemplate.find(query, User.class));
}
谢谢,
推荐答案
您可以重构代码以创建 $or
表达式.不需要显式的 $and
运算符.
You can refactor your code to create $or
expressions. No explicit $and
operator needed.
有点像
Query orQuery = new Query();
Criteria orCriteria = new Criteria();
List<Criteria> orExpression = new ArrayList<>();
for (Map<String, Object> accounts : attributes) {
Criteria expression = new Criteria();
accounts.forEach((key, value) -> expression.and(key).is(value));
orExpression.add(expression);
}
orQuery.addCriteria(orCriteria.orOperator(orExpression.toArray(new Criteria[orExpression.size()])));
List<User> userList = mongoOperations.find(orQuery, User.class);
这应该像这样输出查询
{ "$or" : [{ "key1" : "value1", "key2" : "value2" }, { "key3" : "value3", "key4" : "value4" }] }
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