Springboot使用MongoDB（3）

1.查询索引
2.删除索引
3.创建索引
- 单列索引、复合索引、多键值索引
4.使用索引查询
5.索引的特性

1.查询索引

List<IndexInfo> indexInfo = mongoTemplate.indexOps(Student.class).getIndexInfo();

2.删除索引

mongoTemplate.indexOps(Student.class).dropIndex("age_1");
mongoTemplate.indexOps(Student.class).dropAllIndexes();

3.创建索引

单列索引、复合索引、多键值索引

全文索引，hash索引，地理位置索引（2d或2dSphere）目前只支持注解，但是不知道为什么我测试没有生效。个人还是更习惯直接命令行创建索引

@Test
void testCreateIndex() {
    //1.创建单列索引
    Index index = new Index().on("age", Sort.Direction.ASC);
    String indexName = mongoTemplate.indexOps(Student.class).ensureIndex(index);
    Console.log(indexName);
    //2.创建复合索引
    Index compoundIndex = new Index().on("name", Sort.Direction.ASC).on("age", Sort.Direction.ASC);
    indexName = mongoTemplate.indexOps(Student.class).ensureIndex(compoundIndex);
    Console.log(indexName);
    //3.创建多键值索引(tags列为字符串数组)
    Index multiKeyValueIndex = new Index().on("tags", Sort.Direction.DESC);
    indexName = mongoTemplate.indexOps(Student.class).ensureIndex(multiKeyValueIndex);
    Console.log(indexName);
}

4.使用索引查询

单列索引，复合索引，多键值索引，hash索引

常规find()查询即可

全文索引

与命令相同，包括find查询以及aggregate查询两种
使用TextCriteria来封装查询条件

//1.find查询
List<Student> students = mongoTemplate.find(new Query(TextCriteria.forDefaultLanguage().matching("1")), Student.class);
Assert.isTrue(1 == students.size());
Assert.isTrue("1".equals(students.get(0).getId()));
//2.聚合查询
MatchOperation matchOperation = Aggregation.match(new TextCriteria().forDefaultLanguage().matching("1"));
TypedAggregation<Student> typedAggregation = Aggregation.newAggregation(Student.class, matchOperation);
AggregationResults<Student> aggregate = mongoTemplate.aggregate(typedAggregation, Student.class);
Student result = aggregate.getUniqueMappedResult();
Assert.isTrue("1".equals(result.getId()));

地理位置索引数据点示例

:::info 定义四个数据点（北京、大同、太原、湖南）
以北京为圆心

北京距离大同约等于300km
北京距离太原约等于500km
北京距离湖南约等于1750km :::
2d平面-地理位置索引
实体类
```java import lombok.Data; import org.springframework.data.mongodb.core.index.CompoundIndex; import org.springframework.data.mongodb.core.index.CompoundIndexes; import org.springframework.data.mongodb.core.mapping.Document;

/**

@author 冯铁城 [17615007230@163.com]
@date 2022-07-25 20:18:40

@describe: */ @Data @Document(collection = “geo”) public class Flat {

private String id;

private String name;

private double[] loc; }

<a name="rL6Yg"></a>
#### find查询
find查询可以不指定maxDistance的单位。平面maxDistance默认单位为1度，1度约等于111km
```java
@Test
void testSelect() {
 //1.定义平面坐标点
 List<Flat> flats = CollUtil.newArrayList();
 Flat flat = new Flat();
 flat.setName("北京");
 flat.setLoc(new double[]{115.25, 39.26});
 flats.add(flat);
 flat = new Flat();
 flat.setName("大同");
 flat.setLoc(new double[]{112.34, 39.03});
 flats.add(flat);
 flat = new Flat();
 flat.setName("太原");
 flat.setLoc(new double[]{111.3, 37.27});
 flats.add(flat);
 flat = new Flat();
 flat.setName("湖南");
 flat.setLoc(new double[]{108.47, 24.38});
 flats.add(flat);
 mongoTemplate.insert(flats, Flat.class);
 //3.全量查询,无最大距离
 Point point = new Point(115.28, 39.23);
 List<Flat> result = mongoTemplate.find(new Query(Criteria.where("loc").near(point)), Flat.class);
 Assert.isTrue(4 == result.size());
 //3.非全量查询,有最大距离
 point = new Point(115.28, 39.23);
 result = mongoTemplate.find(new Query(Criteria.where("loc").near(point).maxDistance(3)), Flat.class);
 Assert.isTrue(2 == result.size());
}

geoNear查询

geoNear的优点是可以返回点之间的距离，也可以通过Metrics来指定maxDistance单位，如果不指定，默认单位为1度，约等于111km
geoNear返回的distance默认单位为km

@Test
void testSelect() {
 //1.定义平面坐标点
 List<Flat> flats = CollUtil.newArrayList();
 Flat flat = new Flat();
 flat.setName("北京");
 flat.setLoc(new double[]{115.25, 39.26});
 flats.add(flat);
 flat = new Flat();
 flat.setName("大同");
 flat.setLoc(new double[]{112.34, 39.03});
 flats.add(flat);
 flat = new Flat();
 flat.setName("太原");
 flat.setLoc(new double[]{111.3, 37.27});
 flats.add(flat);
 flat = new Flat();
 flat.setName("湖南");
 flat.setLoc(new double[]{108.47, 24.38});
 flats.add(flat);
 mongoTemplate.insert(flats, Flat.class);
 //2.定义圆心点
 Point point = new Point(115.28, 39.23);
 //3.全量查询,无最大距离
 NearQuery nearQuery = NearQuery.near(point);
 GeoResults<Flat> geoResults = mongoTemplate.geoNear(nearQuery, Flat.class);
 List<GeoResult<Flat>> content = geoResults.getContent();
 Assert.isTrue(4 == content.size());
 //4.非全量查询,有最大距离
 nearQuery = NearQuery.near(point).maxDistance(300, Metrics.KILOMETERS);
 geoResults = mongoTemplate.geoNear(nearQuery, Flat.class);
 content = geoResults.getContent();
 Assert.isTrue(2 == content.size());
}

2dsphere球面-地理位置索引

实体类

球面索引的坐标点，建议用GeoJsonPoint来映射。因为2dsphere索引的列，值得类型允许经纬度数据或geoJson类型。建议使用geoJson类型 ```java import lombok.Data; import org.springframework.data.mongodb.core.geo.GeoJsonPoint; import org.springframework.data.mongodb.core.mapping.Document;

/**

@author 冯铁城 [17615007230@163.com]
@date 2022-07-25 20:18:40

@describe: */ @Data @Document(collection = “geo”) public class Flat {

private String id;

private String name;

private GeoJsonPoint point; }

<a name="kgcOr"></a>
#### find查询
nearSphere可以进行球面查询，缺点是不能返回点之间的距离。球面索引默认maxDistance单位为1m
```java
@Test
void testSelect() {
 //1.定义平面坐标点
 List<Flat> flats = CollUtil.newArrayList();
 Flat flat = new Flat();
 flat.setName("北京");
 flat.setPoint(new GeoJsonPoint(115.25, 39.26));
 flats.add(flat);
 flat = new Flat();
 flat.setName("大同");
 flat.setPoint(new GeoJsonPoint(112.34, 39.03));
 flats.add(flat);
 flat = new Flat();
 flat.setName("太原");
 flat.setPoint(new GeoJsonPoint(111.3, 37.27));
 flats.add(flat);
 flat = new Flat();
 flat.setName("湖南");
 flat.setPoint(new GeoJsonPoint(108.47, 24.38));
 flats.add(flat);
 mongoTemplate.insert(flats, Flat.class);
 //2.定义圆心点
 GeoJsonPoint point = new GeoJsonPoint(115.28, 39.23);
 //3.全量查询,无最大距离
 List<Flat> result = mongoTemplate.find(new Query(Criteria.where("point").nearSphere(point)), Flat.class);
 Assert.isTrue(4 == result.size());
 //4.非全量查询，有最大距离
 result = mongoTemplate.find(new Query(Criteria.where("point").nearSphere(point).maxDistance(300000)), Flat.class);
 Assert.isTrue(2 == result.size());
}

geoNear查询

geoNear的优点是可以返回点之间的距离，也可以通过Metrics来指定maxDistance单位，如果不指定，默认单位为1m
geoNear返回的distance默认单位为km

@Test
void testSelect() {
 //1.定义平面坐标点
 List<Flat> flats = CollUtil.newArrayList();
 Flat flat = new Flat();
 flat.setName("北京");
 flat.setPoint(new GeoJsonPoint(115.25, 39.26));
 flats.add(flat);
 flat = new Flat();
 flat.setName("大同");
 flat.setPoint(new GeoJsonPoint(112.34, 39.03));
 flats.add(flat);
 flat = new Flat();
 flat.setName("太原");
 flat.setPoint(new GeoJsonPoint(111.3, 37.27));
 flats.add(flat);
 flat = new Flat();
 flat.setName("湖南");
 flat.setPoint(new GeoJsonPoint(108.47, 24.38));
 flats.add(flat);
 mongoTemplate.insert(flats, Flat.class);
 //2.定义圆心点
 GeoJsonPoint point = new GeoJsonPoint(115.28, 39.23);
 //3.全量查询,无最大距离
 NearQuery nearQuery = NearQuery.near(point);
 GeoResults<Flat> geoResults = mongoTemplate.geoNear(nearQuery, Flat.class);
 List<GeoResult<Flat>> content = geoResults.getContent();
 Assert.isTrue(4 == content.size());
 //4.非全量查询,有最大距离
 nearQuery = NearQuery.near(point).maxDistance(1800, Metrics.KILOMETERS);
 geoResults = mongoTemplate.geoNear(nearQuery, Flat.class);
 content = geoResults.getContent();
 Assert.isTrue(4 == content.size());
 //5.指定查询两点之间距离
 nearQuery = NearQuery.near(point).maxDistance(1800, Metrics.KILOMETERS)
     .query(new Query(Criteria.where("name").is("湖南")));
 geoResults = mongoTemplate.geoNear(nearQuery, Flat.class);
 content = geoResults.getContent();
 Assert.isTrue(1 == content.size());
 Assert.isTrue("湖南".equals(content.get(0).getContent().getName()));
 System.out.println("北京到湖南之间的距离:" + content.get(0).getDistance().getValue());
}

在规定球形范围内查询

@Test
void testSelect() {
 //1.定义平面坐标点
 List<Flat> flats = CollUtil.newArrayList();
 Flat flat = new Flat();
 flat.setName("北京");
 flat.setPoint(new GeoJsonPoint(115.25, 39.26));
 flats.add(flat);
 flat = new Flat();
 flat.setName("大同");
 flat.setPoint(new GeoJsonPoint(112.34, 39.03));
 flats.add(flat);
 flat = new Flat();
 flat.setName("太原");
 flat.setPoint(new GeoJsonPoint(111.3, 37.27));
 flats.add(flat);
 flat = new Flat();
 flat.setName("湖南");
 flat.setPoint(new GeoJsonPoint(108.47, 24.38));
 flats.add(flat);
 mongoTemplate.insert(flats, Flat.class);
 //2.定义圆心点
 GeoJsonPoint point = new GeoJsonPoint(115.28, 39.23);
 //3.定义半径
 Distance distance = new Distance(300, Metrics.KILOMETERS);
 //4.绘制原型
 Circle circle = new Circle(point, distance);
 //5.查询
 List<Flat> results = mongoTemplate.find(new Query(Criteria.where("point").withinSphere(circle)), Flat.class);
 Assert.isTrue(2 == results.size());
}

5.索引的特性

实体类

```java import lombok.Data; import org.springframework.data.mongodb.core.mapping.Document;

import java.util.Date;

/**

@author 冯铁城 [17615007230@163.com]
@date 2022-07-20 19:12:01
@describe: MongoDB实体类

“@Document(collection = “student”)” 用于指定对应哪个集合 */ @Data @Document(collection = “student”) public class Student {

/**

主键ID */ private Integer id;

/**
学号 */ private String sno;

/**
名称 */ private String name;

/**
年龄 */ private Integer age;

/**
昵称 */ private String nikeName;

/**
描述 */ private String des;

/**

创建时间 */ private Date createTime; }

<a name="sQIln"></a>
### 集合已创建
![image.png](https://cdn.nlark.com/yuque/0/2022/png/28218714/1658901352627-644063f3-f953-4179-90a5-7e82616b510f.png#clientId=u93f7c3a1-7489-4&crop=0&crop=0&crop=1&crop=1&errorMessage=unknown%20error&from=paste&height=49&id=ua06b33f3&margin=%5Bobject%20Object%5D&name=image.png&originHeight=73&originWidth=393&originalType=binary&ratio=1&rotation=0&showTitle=false&size=3745&status=error&style=none&taskId=u940986e5-0f2b-47c0-be2b-52820f1fe49&title=&width=262)
<a name="qIihB"></a>
### 唯一性设置并验证
学号：unique唯一性
```java
@Test
void testUnique() {
//1.创建学号唯一索引
Index snoIndex = new Index().on("sno", Sort.Direction.ASC).unique();
mongoTemplate.indexOps(Student.class).ensureIndex(snoIndex);
//2.保存数据
Student student = new Student();
student.setId(1);
student.setSno("1");
mongoTemplate.insert(student);
//3.再次保存数据
student = new Student();
student.setId(2);
student.setSno("1");
try{
 mongoTemplate.insert(student);
}catch (Exception e){
 Assert.isTrue(e.getMessage().contains("java_test.student index: sno_1 dup key: { sno: \"1\" }"));
}
}

稀疏性设置并验证

昵称：sparse稀疏性

@Test
void testSparse() {
//1.创建昵称唯一索引
Index nikeNameIndex = new Index().on("nikeName", Sort.Direction.ASC).unique();
String indexName = mongoTemplate.indexOps(Student.class).ensureIndex(nikeNameIndex);
//2.保存数据
Student student = new Student();
student.setId(1);
student.setNikeName("xxx1");
mongoTemplate.insert(student);
//3.保存1条不包含昵称的数据
student = new Student();
student.setId(2);
mongoTemplate.insert(student);
//4.再次保存1条不包含昵称的数据
student = new Student();
student.setId(3);
try {
 mongoTemplate.insert(student);
} catch (Exception e) {
 Assert.isTrue(e.getMessage().contains("nikeName_1 dup key: { nikeName: null }"));
}
//5.重新创建索引设置唯一性和稀疏性
mongoTemplate.indexOps(Student.class).dropIndex(indexName);
nikeNameIndex = new Index().on("nikeName", Sort.Direction.ASC).unique().sparse();
mongoTemplate.indexOps(Student.class).ensureIndex(nikeNameIndex);
//6.再次保存2条不包含昵称的数据,无异常抛出
student = new Student();
student.setId(3);
mongoTemplate.insert(student);
student = new Student();
student.setId(4);
mongoTemplate.insert(student);
}

部分性设置并验证

年龄：partial部分性

@Test
void testPartial() {
//1.设置索引
Index ageIndex = new Index().on("age", Sort.Direction.ASC)
 .partial(PartialIndexFilter.of(Criteria.where("age").gt(6)));
//2.创建索引
mongoTemplate.indexOps(Student.class).ensureIndex(ageIndex);
}

具体代码怎么验证暂时没想到，从命令行查询，如图，age字段部分索引创建成功

TTL性设置并验证

@Test
void testTtl() {
//1.设置ttl索引
Index createTimeIndex = new Index().on("createTime", Sort.Direction.ASC).expire(10, TimeUnit.SECONDS);
mongoTemplate.indexOps(Student.class).ensureIndex(createTimeIndex);
//2.存入数据
Student student = new Student();
student.setId(1);
student.setCreateTime(new Date());
//3.沉睡10s钟
try {
 TimeUnit.SECONDS.sleep(10);
} catch (InterruptedException e) {
 throw new RuntimeException(e);
}
//4.再次查询
Student result = mongoTemplate.findOne(new Query(), Student.class);
Assert.isNull(result);
}

1.查询索引

2.删除索引

3.创建索引

单列索引、复合索引、多键值索引

4.使用索引查询

单列索引，复合索引，多键值索引，hash索引

全文索引

地理位置索引数据点示例

2d平面-地理位置索引

实体类

geoNear查询

2dsphere球面-地理位置索引

实体类

geoNear查询

在规定球形范围内查询

5.索引的特性

实体类

稀疏性设置并验证

部分性设置并验证

TTL性设置并验证