package main
import (
	"database/sql"
	"fmt"
	_ "github.com/go-sql-driver/mysql"
	"strings"
)
/**
  自動將表生成 model結構，
 通過創建數據庫連接，讀取數據庫的所有表并對所有的表元數據封裝轉化實體結構體
*/
type SchemaMeta struct {
	Field   string
	Type    string
	Null    string
	Key     string
	Default interface{}
	Extra   string
}
func main() {
	dbString := "{YOUR_MYSQL_CONNECTION}"
	db, _ := sql.Open("mysql", dbString)
	tables := getTables(db)
	for _, table := range tables {
		metas := getTableInfo(table, db)
		result := changeMetas(table, metas)
		fmt.Println(result)
	}
}
func getTables(db *sql.DB) []string {
	var tables []string
	res, _ := db.Query("SHOW TABLES")
	for res.Next() {
		var table string
		res.Scan(&table)
		tables = append(tables, table)
	}
	return tables
}
func getTableInfo(tableName string, db *sql.DB) (metas []SchemaMeta) {
	list, _ := db.Query(fmt.Sprintf("show columns from %s", tableName))
	for list.Next() {
		var data SchemaMeta
		err := list.Scan(&data.Field, &data.Type, &data.Null, &data.Key, &data.Default, &data.Extra)
		if err != nil {
			fmt.Println(err.Error())
		}
		metas = append(metas, data)
	}
	return metas
}
func changeMetas(tableName string, metas []SchemaMeta) string {
	var modelStr string
	for _, val := range metas {
		dataType := "interface{}"
		if val.Type[:3] == "int" {
			dataType = "int"
		} else if val.Type[:7] == "varchar" {
			dataType = "string"
		} else if val.Type[:7] == "tinyint" {
			dataType = "bool"
		} else if val.Type == "datetime" {
			dataType = "time.Time"
		}
		field := val.Field
		field = strings.ToUpper(field[:1]) + field[1:]
		modelStr += fmt.Sprintf("%s %s\n", field, dataType)
	}
	tableName = strings.ToUpper(tableName[:1]) + tableName[1:]
	return fmt.Sprintf("type %s struct {\n %s }", tableName, modelStr)
}

show databases 查看所有的數據庫
show tables [from dbName] 查看數據庫的所有表數據
show columns from tableName [from dbName] 查看數據庫表的所有元信息
show status 查看數據服務的狀態

func getTableInfo(tableName string, db *sql.DB) (metas []SchemaMeta) {
    list, _ := db.Query(fmt.Sprintf("show columns from %s", tableName))
    for list.Next() {
        var data SchemaMeta
        err := list.Scan(&data.Field, &data.Type, &data.Null, &data.Key, &data.Default, &data.Extra)
        if err != nil {
            fmt.Println(err.Error())
        }
        metas = append(metas, data)
    }
    return metas
}