go-zero model命令

2022-04-22 10:38 更新

model命令

goctl model 为go-zero下的工具模块中的组件之一，目前支持识别mysql ddl进行model层代码生成，通过命令行或者idea插件（即将支持）可以有选择地生成带redis cache或者不带redis cache的代码逻辑。

快速开始

通过ddl生成

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

执行上述命令后即可快速生成CURD代码。

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

通过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"`   // 学号
        Name       string    `db:"name"`     // 用户名称
        Password   string    `db:"password"` // 用户密码
        Gender     string    `db:"gender"`   // 男｜女｜未公开
        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

生成规则

默认规则

我们默认用户在建表时会创建createTime、updateTime字段(忽略大小写、下划线命名风格)且默认值均为CURRENT_TIMESTAMP，而updateTime支持ON UPDATE CURRENT_TIMESTAMP，对于这两个字段生成insert、update时会被移除，不在赋值范畴内，当然，如果你不需要这两个字段那也无大碍。

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

生成代码仅基本的CURD结构。

缓存

对于缓存这一块我选择用一问一答的形式进行罗列。我想这样能够更清晰的描述model中缓存的功能。

缓存会缓存哪些信息？

对于主键字段缓存，会缓存整个结构体信息，而对于单索引字段（除全文索引）则缓存主键字段值。

数据有更新（update）操作会清空缓存吗？

会，但仅清空主键缓存的信息，why？这里就不做详细赘述了。

为什么不按照单索引字段生成updateByXxx和deleteByXxx的代码？

理论上是没任何问题，但是我们认为，对于model层的数据操作均是以整个结构体为单位，包括查询，我不建议只查询某部分字段（不反对），否则我们的缓存就没有意义了。

为什么不支持findPageLimit、findAll这种模式代码生成？

目前，我认为除了基本的CURD外，其他的代码均属于业务型代码，这个我觉得开发人员根据业务需要进行编写更好。

类型转换规则

mysql dataType	golang dataType	golang dataType(if null&&default null)
bool	int64	sql.NullInt64
boolean	int64	sql.NullInt64
tinyint	int64	sql.NullInt64
smallint	int64	sql.NullInt64
mediumint	int64	sql.NullInt64
int	int64	sql.NullInt64
integer	int64	sql.NullInt64
bigint	int64	sql.NullInt64
float	float64	sql.NullFloat64
double	float64	sql.NullFloat64
decimal	float64	sql.NullFloat64
date	time.Time	sql.NullTime
datetime	time.Time	sql.NullTime
timestamp	time.Time	sql.NullTime
time	string	sql.NullString
year	time.Time	sql.NullInt64
char	string	sql.NullString
varchar	string	sql.NullString
binary	string	sql.NullString
varbinary	string	sql.NullString
tinytext	string	sql.NullString
text	string	sql.NullString
mediumtext	string	sql.NullString
longtext	string	sql.NullString
enum	string	sql.NullString
set	string	sql.NullString
json	string	sql.NullString

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