Category Column: MongoDB
Disclaimer: This article is a blogger original article, follow the CC 4.0 BY-SA copyright agreement, reproduced, please attach the original source link and this statement.
Mongodb query requires the use of complex or stitching and parameters and
There MongoDb table:
|
1
|
"state1" : 11,
|
"state2" : 21,
|
"value" : 100
|
|
2
|
"state1" : 11,
|
"state2" : 22,
|
"value" : 300
|
|
3
|
"state1" : 11,
|
"state2" : 22,
|
"value" : 200
|
|
4
|
"state1" : 12,
|
"state2" : 21,
|
"value" : 300
|
To achieve the management of data in the form of the following SQL:
Relational Database: select * from where (state1 = 11 and state2 = 22) or value> 300
The first to use MongoDB query ways:
Divided into the following steps to achieve:
Step a: implement (state1 = 11 and state2 = 22)
db.getCollection('testOrAnd').find(
{$and:[{"state1":11},{"state2":22}]}
)
Step 2: Using or forms of implementing the value> 300
db.getCollection('testOrAnd'). find(
{ $or:[{"value":{$gte:300}}] }
)
Step 3: the step of splicing parameters to a two step or conditions
db.getCollection('testOrAnd').
find({$or:
[
{$and:[{"state1":11},{"state2":22}]},{"value":{$gte:300}}
]
})
Ultimately result:
Use spring-mongotemplate way to query (Criteria.where a static method):
Query analysis, a similar analysis using client mode, divided into the following steps to achieve:
Step a: implement (state1 = 11 and state2 = 22)
query.addCriteria(
new Criteria().andOperator(
Criteria.where("state1").is(11),
Criteria.where("state2").is(22)
)
);
Step 2: Using or forms of implementing the value> 300
query.addCriteria(
new Criteria().orOperator(
Criteria.where("value").gte(300)
)
);
步骤三：将步骤一参数拼接到步骤二or条件
query.addCriteria(
new Criteria().orOperator(
Criteria.where("value").gte(300),
new Criteria().andOperator(
Criteria.where("state1").is(11),
Criteria.where("state2").is(22)
)
)
);
升级查询，实际场景中要根据传输的参数是否为空，拼接查询条件：
(1)如果最外层是and关系(query.add多个creterria默认为and关系)
if(条件){
query.addCriteria(Criteria.where);
}
if(条件){
query.addCriteria(Criteria.where);
}
if(条件){
query.addCriteria(Criteria.where);
}
默认拼接的query条件为and形式。
(1)如果最外层是or关系(目前只想到此笨方法)
//1.拼接参数
Criteria operator1=null;
Criteria operator2=null;
if(1==1){//模拟判断条件
operator1 = new Criteria().andOperator(
Criteria.where("state1").is(11),
Criteria.where("state2").is(22)
);
}
if(1==1){//模拟判断条件
operator2 = Criteria.where("value").gte(300);
}
//2.判断参数
if(operator1!=null && operator2!=null){
query.addCriteria(new Criteria().orOperator(operator1,operator2));
}else if(operator1!=null){
query.addCriteria(operator1);
}else if(operator2!=null){
query.addCriteria(operator2);
}
补充：多个条件直接查询，默认是and形式
db.getCollection('testOrAnd').find({"state1":11,"state2":22})
即query.add多个creterria默认为and关系