golang嵌入式数据库boltdb工具之storm的使用

storm是一个使用BoltDB的上层orm框架

地址:

• 数据查看工具: https://github.com/br0xen/boltbrowser
• 驱动: https://github.com/asdine/storm

初始化#

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1 2	db, err := storm.Open("my.db") defer db.Close()

　　

对象模型#

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type User struct {   ID int // primary key   Group string `storm:"index"` // this field will be indexed   Email string `storm:"unique"` // this field will be indexed with a unique constraint   Name string // this field will not be indexed   Age int `storm:"index"` }

对象模型storm tag整理#

　　可以符合使用, 各个值用 , (逗号) 分割

1. storm:"index"                添加索引
2. storm:"id"                     主键标识
3. storm:"increment"          自增字段
4. storm:"increment=20"     自增字段, 从20开始自增
5. storm:"unique"               不能重复
6. storm:"inline"                 内联标记嵌套
7. storm:"__storm_index_"   ???

保存数据#

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user := User{   ID: 10,   Group: "staff",   Email: "john@provider.com",   Name: "John",   Age: 21,   CreatedAt: time.Now(), }   err := db.Save(&user) // err == nil   user.ID++ err = db.Save(&user) // err == storm.ErrAlreadyExists

　　

修改#

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// Update multiple fields err := db.Update(&User{ID: 10, Name: "Jack", Age: 45})   // Update a single field err := db.UpdateField(&User{ID: 10}, "Age", 0)

　　

删除数据#

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1	err := db.DeleteStruct(&user)

　　

表管理操作#

• 初始化索引 err := db.Init(&User{})
• 重建索引: err := db.ReIndex(&User{})
• 删表: err := db.Drop(&User) 或 err := db.Drop("User")

简单查询#

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var user User err := db.One("Email", "john@provider.com", &user) // err == nil   err = db.One("Name", "John", &user) // err == nil   err = db.One("Name", "Jack", &user) // err == storm.ErrNotFound   // Fetch multiple objects var users []User err := db.Find("Group", "staff", &users)   // Fetch all objects var users []User err := db.All(&users)   // Fetch all objects sorted by index var users []User err := db.AllByIndex("CreatedAt", &users)   // Fetch a range of objects var users []User err := db.Range("Age", 10, 21, &users)   // Fetch objects by prefix var users []User err := db.Prefix("Name", "Jo", &users)   // Skip, Limit and Reverse var users []User err := db.Find("Group", "staff", &users, storm.Skip(10)) err = db.Find("Group", "staff", &users, storm.Limit(10)) err = db.Find("Group", "staff", &users, storm.Reverse()) err = db.Find("Group", "staff", &users, storm.Limit(10), storm.Skip(10), storm.Reverse())   err = db.All(&users, storm.Limit(10), storm.Skip(10), storm.Reverse()) err = db.AllByIndex("CreatedAt", &users, storm.Limit(10), storm.Skip(10), storm.Reverse()) err = db.Range("Age", 10, 21, &users, storm.Limit(10), storm.Skip(10), storm.Reverse())

　　

高级查询#

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import (   "github.com/asdine/storm/q"<br>)...<br><br>// Equality q.Eq("Name", John)   // Strictly greater than q.Gt("Age", 7)   // Lesser than or equal to q.Lte("Age", 77)   // Regex with name that starts with the letter D q.Re("Name", "^D")   // In the given slice of values q.In("Group", []string{"Staff", "Admin"})   // Comparing fields q.EqF("FieldName", "SecondFieldName") q.LtF("FieldName", "SecondFieldName") q.GtF("FieldName", "SecondFieldName") q.LteF("FieldName", "SecondFieldName") q.GteF("FieldName", "SecondFieldName")   // Match if all match q.And(   q.Gt("Age", 7),   q.Re("Name", "^D") )   // Matchers can also be combined with And, Or and Not: // Match if one matches q.Or(   q.Re("Name", "^A"),   q.Not(     q.Re("Name", "^B")   ),   q.Re("Name", "^C"),   q.In("Group", []string{"Staff", "Admin"}),   q.And(     q.StrictEq("Password", []byte(password)),     q.Eq("Registered", true)   ) )   query := db.Select(q.Gte("Age", 7), q.Lte("Age", 77)) // Calls can also be chained query = query.Limit(10).Skip(20).OrderBy("Age").Reverse()   // But also to specify how to fetch them. var users []User err = query.Find(&users)   var user User err = query.First(&user)     // demo // Examples with Select:   / Find all users with an ID between 10 and 100 err = db.Select(q.Gte("ID", 10), q.Lte("ID", 100)).Find(&users)   // Nested matchers err = db.Select(q.Or(   q.Gt("ID", 50),   q.Lt("Age", 21),   q.And(     q.Eq("Group", "admin"),     q.Gte("Age", 21),   ), )).Find(&users)   query := db.Select(q.Gte("ID", 10), q.Lte("ID", 100)).Limit(10).Skip(5).Reverse().OrderBy("Age", "Name")   // Find multiple records err = query.Find(&users) // or err = db.Select(q.Gte("ID", 10), q.Lte("ID", 100)).Limit(10).Skip(5).Reverse().OrderBy("Age", "Name").Find(&users)   // Find first record err = query.First(&user) // or err = db.Select(q.Gte("ID", 10), q.Lte("ID", 100)).Limit(10).Skip(5).Reverse().OrderBy("Age", "Name").First(&user)   // Delete all matching records err = query.Delete(new(User))   // Fetching records one by one (useful when the bucket contains a lot of records) query = db.Select(q.Gte("ID", 10),q.Lte("ID", 100)).OrderBy("Age", "Name")   err = query.Each(new(User), func(record interface{}) error) {   u := record.(*User)   ...   return nil }

　　

事务#

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tx, err := db.Begin(true) if err != nil {   return err } defer tx.Rollback()   accountA.Amount -= 100 accountB.Amount += 100   err = tx.Save(accountA) if err != nil {   return err }   err = tx.Save(accountB) if err != nil {   return err }   return tx.Commit()

　　

不同的数据编码方式#

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import (   "github.com/asdine/storm/v3"   "github.com/asdine/storm/v3/codec/gob"   "github.com/asdine/storm/v3/codec/json"   "github.com/asdine/storm/v3/codec/sereal"   "github.com/asdine/storm/v3/codec/protobuf"   "github.com/asdine/storm/v3/codec/msgpack" )   var gobDb, _ = storm.Open("gob.db", storm.Codec(gob.Codec)) var jsonDb, _ = storm.Open("json.db", storm.Codec(json.Codec)) var serealDb, _ = storm.Open("sereal.db", storm.Codec(sereal.Codec)) var protobufDb, _ = storm.Open("protobuf.db", storm.Codec(protobuf.Codec)) var msgpackDb, _ = storm.Open("msgpack.db", storm.Codec(msgpack.Codec))

　　

参考连接: http://ystyle.top/2019/12/22/how-to-use-storm-db/