go-zero model命令

model命令

goctl model 為go-zero下的工具模塊中的組件之一，目前支持識別mysql ddl進行model層代碼生成，通過命令行或者idea插件（即將支持）可以有選擇地生成帶redis cache或者不帶redis cache的代碼邏輯。

快速開始

• 通過ddl生成

  $ goctl model mysql ddl -src="./*.sql" -dir="./sql/model" -c

• 執(zhí)行上述命令后即可快速生成CURD代碼。

  model
  ├── usermodel.go
  ├── usermodel_gen.go
  └── vars.go

• 通過datasource生成

  $ goctl model mysql datasource -url="user:password@tcp(127.0.0.1:3306)/database" -table="*"  -dir="./model"

• usermodel_gen.go

// Code generated by goctl. DO NOT EDIT!

package model

import (
    "context"
    "database/sql"
    "fmt"
    "strings"
    "time"

    "github.com/zeromicro/go-zero/core/stores/builder"
    "github.com/zeromicro/go-zero/core/stores/cache"
    "github.com/zeromicro/go-zero/core/stores/sqlc"
    "github.com/zeromicro/go-zero/core/stores/sqlx"
    "github.com/zeromicro/go-zero/core/stringx"
)

var (
    userFieldNames          = builder.RawFieldNames(&User{})
    userRows                = strings.Join(userFieldNames, ",")
    userRowsExpectAutoSet   = strings.Join(stringx.Remove(userFieldNames, "`id`", "`create_time`", "`update_time`"), ",")
    userRowsWithPlaceHolder = strings.Join(stringx.Remove(userFieldNames, "`id`", "`create_time`", "`update_time`"), "=?,") + "=?"

    cacheUserIdPrefix     = "cache:user:id:"
    cacheUserNumberPrefix = "cache:user:number:"
)

type (
    userModel interface {
        Insert(ctx context.Context, data *User) (sql.Result, error)
        FindOne(ctx context.Context, id int64) (*User, error)
        FindOneByNumber(ctx context.Context, number string) (*User, error)
        Update(ctx context.Context, data *User) error
        Delete(ctx context.Context, id int64) error
    }

    defaultUserModel struct {
        sqlc.CachedConn
        table string
    }

    User struct {
        Id         int64     `db:"id"`
        Number     string    `db:"number"`   // 學(xué)號
        Name       string    `db:"name"`     // 用戶名稱
        Password   string    `db:"password"` // 用戶密碼
        Gender     string    `db:"gender"`   // 男｜女｜未公開
        CreateTime time.Time `db:"create_time"`
        UpdateTime time.Time `db:"update_time"`
    }
)

func newUserModel(conn sqlx.SqlConn, c cache.CacheConf) *defaultUserModel {
    return &defaultUserModel{
        CachedConn: sqlc.NewConn(conn, c),
        table:      "`user`",
    }
}

func (m *defaultUserModel) Insert(ctx context.Context, data *User) (sql.Result, error) {
    userIdKey := fmt.Sprintf("%s%v", cacheUserIdPrefix, data.Id)
    userNumberKey := fmt.Sprintf("%s%v", cacheUserNumberPrefix, data.Number)
    ret, err := m.ExecCtx(ctx, func(ctx context.Context, conn sqlx.SqlConn) (result sql.Result, err error) {
        query := fmt.Sprintf("insert into %s (%s) values (?, ?, ?, ?)", m.table, userRowsExpectAutoSet)
        return conn.ExecCtx(ctx, query, data.Number, data.Name, data.Password, data.Gender)
    }, userIdKey, userNumberKey)
    return ret, err
}

func (m *defaultUserModel) FindOne(ctx context.Context, id int64) (*User, error) {
    userIdKey := fmt.Sprintf("%s%v", cacheUserIdPrefix, id)
    var resp User
    err := m.QueryRowCtx(ctx, &resp, userIdKey, func(ctx context.Context, conn sqlx.SqlConn, v interface{}) error {
        query := fmt.Sprintf("select %s from %s where `id` = ? limit 1", userRows, m.table)
        return conn.QueryRowCtx(ctx, v, query, id)
    })
    switch err {
    case nil:
        return &resp, nil
    case sqlc.ErrNotFound:
        return nil, ErrNotFound
    default:
        return nil, err
    }
}

func (m *defaultUserModel) FindOneByNumber(ctx context.Context, number string) (*User, error) {
    userNumberKey := fmt.Sprintf("%s%v", cacheUserNumberPrefix, number)
    var resp User
    err := m.QueryRowIndexCtx(ctx, &resp, userNumberKey, m.formatPrimary, func(ctx context.Context, conn sqlx.SqlConn, v interface{}) (i interface{}, e error) {
        query := fmt.Sprintf("select %s from %s where `number` = ? limit 1", userRows, m.table)
        if err := conn.QueryRowCtx(ctx, &resp, query, number); err != nil {
            return nil, err
        }
        return resp.Id, nil
    }, m.queryPrimary)
    switch err {
    case nil:
        return &resp, nil
    case sqlc.ErrNotFound:
        return nil, ErrNotFound
    default:
        return nil, err
    }
}

func (m *defaultUserModel) Update(ctx context.Context, data *User) error {
    userIdKey := fmt.Sprintf("%s%v", cacheUserIdPrefix, data.Id)
    userNumberKey := fmt.Sprintf("%s%v", cacheUserNumberPrefix, data.Number)
    _, err := m.ExecCtx(ctx, func(ctx context.Context, conn sqlx.SqlConn) (result sql.Result, err error) {
        query := fmt.Sprintf("update %s set %s where `id` = ?", m.table, userRowsWithPlaceHolder)
        return conn.ExecCtx(ctx, query, data.Number, data.Name, data.Password, data.Gender, data.Id)
    }, userIdKey, userNumberKey)
    return err
}

func (m *defaultUserModel) Delete(ctx context.Context, id int64) error {
    data, err := m.FindOne(ctx, id)
    if err != nil {
        return err
    }

    userIdKey := fmt.Sprintf("%s%v", cacheUserIdPrefix, id)
    userNumberKey := fmt.Sprintf("%s%v", cacheUserNumberPrefix, data.Number)
    _, err = m.ExecCtx(ctx, func(ctx context.Context, conn sqlx.SqlConn) (result sql.Result, err error) {
        query := fmt.Sprintf("delete from %s where `id` = ?", m.table)
        return conn.ExecCtx(ctx, query, id)
    }, userIdKey, userNumberKey)
    return err
}

func (m *defaultUserModel) formatPrimary(primary interface{}) string {
    return fmt.Sprintf("%s%v", cacheUserIdPrefix, primary)
}

func (m *defaultUserModel) queryPrimary(ctx context.Context, conn sqlx.SqlConn, v, primary interface{}) error {
    query := fmt.Sprintf("select %s from %s where `id` = ? limit 1", userRows, m.table)
    return conn.QueryRowCtx(ctx, v, query, primary)
}

func (m *defaultUserModel) tableName() string {
    return m.table
}

• usermodel.go

package model

import (
    "github.com/zeromicro/go-zero/core/stores/cache"
    "github.com/zeromicro/go-zero/core/stores/sqlx"
)

var _ UserModel = (*customUserModel)(nil)

type (
    // UserModel is an interface to be customized, add more methods here,
    // and implement the added methods in customUserModel.
    UserModel interface {
        userModel
    }

    customUserModel struct {
        *defaultUserModel
    }
)

// NewUserModel returns a model for the database table.
func NewUserModel(conn sqlx.SqlConn, c cache.CacheConf) UserModel {
    return &customUserModel{
        defaultUserModel: newUserModel(conn, c),
    }
}

用法

$ goctl model mysql -h

NAME:
   goctl model mysql - generate mysql model"

USAGE:
   goctl model mysql command [command options] [arguments...]

COMMANDS:
   ddl         generate mysql model from ddl"
   datasource  generate model from datasource"

OPTIONS:
   --help, -h  show help

生成規(guī)則

• 默認規(guī)則

我們默認用戶在建表時會創(chuàng)建createTime、updateTime字段(忽略大小寫、下劃線命名風格)且默認值均為CURRENT_TIMESTAMP，而updateTime支持ON UPDATE CURRENT_TIMESTAMP，對于這兩個字段生成insert、update時會被移除，不在賦值范疇內(nèi)，當然，如果你不需要這兩個字段那也無大礙。

• ddl

NAME:
   goctl model mysql ddl - generate mysql model from ddl

USAGE:
   goctl model mysql ddl [command options] [arguments...]

OPTIONS:
   --src value, -s value         the path or path globbing patterns of the ddl
   --dir value, -d value         the target dir
   --style value                 the file naming format, see [https://github.com/zeromicro/go-zero/tree/master/tools/goctl/config/readme.md]
   --cache, -c                   generate code with cache [optional]
   --idea                        for idea plugin [optional]
   --database value, --db value  the name of database [optional]
   --home value                  the goctl home path of the template, --home and --remote cannot be set at the same time, if they are, --remote has higher priority
   --remote value                the remote git repo of the template, --home and --remote cannot be set at the same time, if they are, --remote has higher priority
                                 The git repo directory must be consistent with the https://github.com/zeromicro/go-zero-template directory structure
   --branch value                the branch of the remote repo, it does work with --remote

• datasource

$ goctl model mysql datasource -h                       ? 13:40:46  羽106ms
NAME:
   goctl model mysql datasource - generate model from datasource

USAGE:
   goctl model mysql datasource [command options] [arguments...]

OPTIONS:
   --url value              the data source of database,like "root:password@tcp(127.0.0.1:3306)/database"
   --table value, -t value  the table or table globbing patterns in the database
   --cache, -c              generate code with cache [optional]
   --dir value, -d value    the target dir
   --style value            the file naming format, see [https://github.com/zeromicro/go-zero/tree/master/tools/goctl/config/readme.md]
   --idea                   for idea plugin [optional]
   --home value             the goctl home path of the template, --home and --remote cannot be set at the same time, if they are, --remote has higher priority
   --remote value           the remote git repo of the template, --home and --remote cannot be set at the same time, if they are, --remote has higher priority
                            The git repo directory must be consistent with the https://github.com/zeromicro/go-zero-template directory structure
   --branch value           the branch of the remote repo, it does work with --remote

生成代碼僅基本的CURD結(jié)構(gòu)。

緩存

對于緩存這一塊我選擇用一問一答的形式進行羅列。我想這樣能夠更清晰的描述model中緩存的功能。

• 緩存會緩存哪些信息？

對于主鍵字段緩存，會緩存整個結(jié)構(gòu)體信息，而對于單索引字段（除全文索引）則緩存主鍵字段值。

• 數(shù)據(jù)有更新（update）操作會清空緩存嗎？

會，但僅清空主鍵緩存的信息，why？這里就不做詳細贅述了。

• 為什么不按照單索引字段生成updateByXxx和deleteByXxx的代碼？

理論上是沒任何問題，但是我們認為，對于model層的數(shù)據(jù)操作均是以整個結(jié)構(gòu)體為單位，包括查詢，我不建議只查詢某部分字段（不反對），否則我們的緩存就沒有意義了。

• 為什么不支持findPageLimit、findAll這種模式代碼生成？

目前，我認為除了基本的CURD外，其他的代碼均屬于業(yè)務(wù)型代碼，這個我覺得開發(fā)人員根據(jù)業(yè)務(wù)需要進行編寫更好。

類型轉(zhuǎn)換規(guī)則