GOLANG para BASES DE DATOS

---

MYSQL

driver

go-sql-driver

go get -u github.com/go-sql-driver/mysql

Crear conexion a la BBDD

package store

import (
    "database/sql"
    "fmt"

    // mysql driver
    _ "github.com/go-sql-driver/mysql"
)

type configDB struct {
    DatabaseType string `json:"databaseType"`
    Host         string `json:"host"`
    Port         int    `json:"port"`
    DB           string `json:"db"`
    User         string `json:"user"`
    Password     string `json:"password"`
}

// DB ...
type DB struct {
    *sql.DB
}

// NewDB ...
func NewDB(mode string) (*DB, error) {
    var c configDB
    loadConfigJSON(&c)
    setDBConnConfig(mode, &c)
    connPath := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?parseTime=true",
        c.User,
        c.Password,
        c.Host,
        c.Port,
        c.DB,
    )
    //fmt.Println("CONNPATH => ", connPath)
    db, err := sql.Open(c.DatabaseType, connPath)
    if err != nil {
        return nil, err
    }
    err = db.Ping()
    if err != nil {
        return nil, err
    }
    return &DB{db}, nil
}

// lo llamo desde otro paquete
package login

import (
    store "casServer/login/store"
)

var loginDB *store.DB

func init() {
    db, err := store.NewDB(checkAppConfMode())
    if err != nil {
        log.Fatal("Error connecting DataBase => ", err)
    }
    loginDB = db
    //users, _ := loginDB.AccountList()
    //fmt.Println(len(users))

}

Select

func (loginDB *DB) Account(name string) (*User, error) {
    //fmt.Println("SEARCHING ...", name)
    u := new(User)
    query := fmt.Sprintf(`
        SELECT
            *
        FROM %s
        WHERE nickID=?
        `,
        usersTable,
    )
    //fmt.Println(query)
    stmt, err := loginDB.Prepare(query)
    if err != nil {
        log.Printf("ERROR 1 DB %s\n", err)
        return u, err
    }
    defer stmt.Close()
    err = stmt.QueryRow(name).Scan(
        &u.NickID,
        &u.Nick,
        &u.PassHashed,
        &u.Email,
        &u.Verified,
        &u.Logo,
        &u.SecretQuest,
        &u.SecretHashed,
        &u.CreatedAt,
        &u.LastSeen,
        &u.Online)
    if err != nil {
        if err == sql.ErrNoRows { // no result
            //log.Println("NO RESULT", u)
            return u, nil
        }
        log.Printf("ERROR 2 DB %s\n", err)
        return nil, err
    }
    return u, nil
}

func (loginDB *DB) AccountList() ([]*User, error) {
    query := fmt.Sprintf(`
        SELECT
            nickID
        FROM %s
        `,
        usersTable,
    )
    stmt, err := loginDB.Prepare(query)
    if err != nil {
        return nil, err
    }
    defer stmt.Close()

    rows, err := stmt.Query()
    if err != nil {
        return nil, err
    }
    defer rows.Close()
    users := make([]*User, 0)
    for rows.Next() {
        user := new(User)
        err := rows.Scan(
            &user.NickID,
        )
        if err != nil {
            return nil, err
        }
        users = append(users, user)
    }
    return users, nil
}

func (loginDB *DB) UserSession(usernameID string) (*Session, error) {
    s := NewSession()
    query := fmt.Sprintf(`
        SELECT
            *
        FROM %s
        WHERE nickID=?
        `,
        sessionsTable,
    )
    stmt, err := loginDB.Prepare(query)
    if err != nil {
        log.Printf("ERROR 3 DB SESSIONS %s\n", err)
        return s, err
    }
    defer stmt.Close()
    err = stmt.QueryRow(usernameID).Scan(
        &s.NickID,
        &s.SessionID,
        &s.Expires,
    )
    if err != nil {
        if err == sql.ErrNoRows { // no result
            //log.Println("NO RESULT", s)
            return s, nil
        }
        log.Printf("ERROR 4 DB SESSIONS %s\n", err)
        return nil, err
    }
    return s, nil
}

Insert

func (loginDB *DB) NewAccount(u *User) error {
    //fmt.Println("USER => ", u)
    query := fmt.Sprintf(`
        INSERT
        INTO %s
        (
            nickID, nick, passHashed, email, verified, logo, 
            secretQuest, secretHashed, createdAt, lastSeen, online
        )
        values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
        `,
        usersTable,
    )
    stmt, err := loginDB.Prepare(query)
    //fmt.Println(query)
    if err != nil {
        log.Printf("ERROR 3 DB USERS %s -> %s\n", u.Nick, err)
        return err
    }
    defer stmt.Close()
    _, err = stmt.Exec(
        u.NickID,
        u.Nick,
        u.PassHashed,
        u.Email,
        u.Verified,
        u.Logo,
        u.SecretQuest,
        u.SecretHashed,
        u.CreatedAt,
        u.LastSeen,
        u.Online,
    )
    if err != nil { 
        log.Printf("ERROR 4 DB USERS %s -> %s\n", u.Nick, err)
        return err
    }
    return nil
}

func (loginDB *DB) SaveSession(s *Session) error {
    query := fmt.Sprintf(`
        INSERT 
        INTO %s 
        (
            nickID, sessionID, expires
        ) 
        values (?, ?, ?)
        ON DUPLICATE KEY UPDATE sessionID=? , expires= ?
        `,
        sessionsTable)
    stmt, err := loginDB.Prepare(query)
    if err != nil {
        log.Printf("ERROR 1 DB SESSIONS %s -> %s\n", s.NickID, err)
        return err
    }
    defer stmt.Close()
    _, err = stmt.Exec(
        s.NickID,
        s.SessionID,
        s.Expires,
        s.SessionID,
        s.Expires,
    )
    if err != nil {
        log.Printf("ERROR 2 DB SESSIONS %s -> %s\n", s.NickID, err)
        return err
    }
    return nil
}

Update

Delete

func (loginDB *DB) DeleteSession(usernameID string) error {
    query := fmt.Sprintf(`
        DELETE 
        FROM %s 
        WHERE nickID = ?
        `,
        sessionsTable)
    stmt, err := loginDB.Prepare(query)
    if err != nil {
        log.Printf("ERROR 5 DB SESSIONS %s -> %s\n", usernameID, err)
        return err
    }
    defer stmt.Close()
    _, err = stmt.Exec(
        usernameID,
    )
    if err != nil {
        log.Printf("ERROR 6 DB SESSIONS %s -> %s\n", usernameID, err)
        return err
    }
    return nil
}