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Seiya
Seiya

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golang generic orm

#go #generic #orm

ggm

golang generic orm, base on sqlx

install 

go get github.com/daodao97/ggm
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usage

Below is an example which shows some common use cases for ggm. Check model_test.go for more usage.

init db

We can initialize some db resources commonly used by programs, like this

// map[conn_name]db_config ggm.Init(map[string]*ggm.Config{ "default": { DSN: "root@tcp(127.0.0.1:3306)/ggm_test?&parseTime=true", }, })
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Of course, we can also instantiate some temporary DB resources, like this

m := ggm.NewConn(&ggm.Config{ DSN: "root@tcp(127.0.0.1:3306)/ggm_test?&parseTime=true" })
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data model

For example, we have a table with the following structure

CREATE TABLE `user` ( `id` int(11) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(50) NOT NULL, `status` tinyint(4) NOT NULL DEFAULT '0', `profile` varchar(200) NOT NULL, `is_deleted` tinyint(3) unsigned NOT NULL DEFAULT '0', `ctime` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP, `mtime` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
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struct define

The structure model for this table is

type User struct { Id int `db:"id,pk" json:"id"` Name string `db:"name" json:"name"` Profile string `db:"profile" json:"profile"` CTime time.Time `db:"ctime" json:"ctime"` } func (u User) Table() string { return "user" }
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interface: Table() string the struct must implement.

struct field must have db tag, value is db field name.

set conn

If you are using a db resource that is not the default

func (u User) Conn() string { return "conn_name" }
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fake delete

If you have a field to mark fake delete

func (u User) FakeDeleteKey() string { return "is_deleted" }
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then, the delete sql will converted to update ${fakeDeleteKey} = 1 when we delete data

select sql will auto add ${fackDeleteKey} = 0, to filter deleted data.

select 

m := ggm.New[*User]() // or ggm.New[User]()  m.Select(ggm.WhereEq("id", 1))
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detail of where condition see where condition

insert 

user := &User{Name: "Seiya"} // single insert m.Insert(user) // batch insert m.Insert(user, user2, ...)
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update

use primary key update 

user := &User{Id: 1, Name: "Seiya!!!"} m.Update(user)
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with where condition 

user := &User{Name: "Seiya!!!"} m.Update(user, ggm.WhereEq("id", 1))
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delete 

m.Delete(ggm.WhereEq("id", 1))
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where condition 

m.Select( WhereEq("id", 1), WhereGt("age", 20), WhereLike("name", "dd"), WhereGroup( WhereEq("sex", 1), WhereOrEq("class", 2), WhereGroup( WhereEq("sex1", 1), WhereEq("class2", 2), ), ), OrderBy("id", DESC), )
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more example, checkout sql_test.go

data type

Json

If the value of field user.profile is json_string like {"skill":"Pegasus Ryuseiken"}

type User struct { Id int `db:"id,pk" json:"id"` Name string `db:"name" json:"name"` Profile *ggm.Json[*Profile] `db:"profile" json:"profile"` CTime time.Time `db:"ctime" json:"ctime"` } type Profile struct { Skill string `json:"skill"` }
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Profile{Skill: "xxx"} <==> '{"skill":"xxx"}'

Data can be automatically converted into struct for use by programs.

Time 

type User struct { Id int `db:"id,pk" json:"id"` Name string `db:"name" json:"name"` Profile *ggm.Json[*Profile] `db:"profile" json:"profile"` CTime ggm.Time `db:"ctime" json:"ctime"` }
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when api response or json.Marshal

ctime : 2022-03-19T11:52:19Z => 2022-03-19 11:52:19

define yourself data type

Implement the following interfaces

type DataType[T any] interface { Value() (driver.Value, error) Scan(value any) error MarshalJSON() ([]byte, error) UnmarshalJSON(b []byte) error Get() T }
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Linked data

hasOne

one to one

type User struct { Id int `db:"id,pk" json:"id"` Name string `db:"name" json:"name"` Profile *Json[*Profile] `db:"profile" json:"profile"` Score int `db:"score" json:"score" hasOne:"user_score:uid"` Score2 int `db:"score2" json:"score2" hasOne:"user_score:uid"` }
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hasMany

one to N

type User struct { Id int `db:"id,pk" json:"id"` Name string `db:"name" json:"name"` Profile *Json[*Profile] `db:"profile" json:"profile"` Logs []*Log `json:"logs" hasMany:"user_log:uid"` } type Log struct { Message string `db:"message" json:"message"` }
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hasOne or hasMany tag token:

[conn.][database.]table:[local_key->]foreign_key

m.Select() will auto query the linked data into the struct.

Check model_test.go for detail.

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