I want to make a backup sql data function in golang. I have written a sample code which will backup the sql database and a command for table too. But I don't know that how to dump the one row data from sql into given path?
For database:
package main
import (
"io/ioutil"
"log"
"os/exec"
)
func main() {
cmd := exec.Command("mysqldump", "-P3306", "-hhost", "-uuser", "-ppassword", "database_name")
stdout, err := cmd.StdoutPipe()
if err != nil {
log.Fatal(err)
}
if err := cmd.Start(); err != nil {
log.Fatal(err)
}
bytes, err := ioutil.ReadAll(stdout)
if err != nil {
log.Fatal(err)
}
err = ioutil.WriteFile("./out.sql", bytes, 0644)
if err != nil {
panic(err)
}
}
For table we can change the command like below:
cmd := exec.Command("mysqldump", "-P3306", "-hhost", "-uuser", "-ppassword", "database_name" "table_name")
For dump the row of a table what should I have to write please any suggestions with short code.
for example: dump that row where id is equals to 1
Related
I have a test suite that pollute my database using a seed read from a YAML file.
I'm wondering is there a way to clean my database (delete all records used for the test suite) after running my tests.
// Open db and returns pointer and closer func
func prepareMySQLDB(t *testing.T) (db *sql.DB, closer func() error) {
db, err := sql.Open("mysql", "user:pass#/database")
if err != nil {
t.Fatalf("open mysql connection: %s", err)
}
return db, db.Close
}
// Pollute my database
func polluteDb(db *sql.DB, t *testing.T) {
seed, err := os.Open("seed.yml")
if err != nil {
t.Fatalf("failed to open seed file: %s", err)
}
defer seed.Close()
p := polluter.New(polluter.MySQLEngine(db))
if err := p.Pollute(seed); err != nil {
t.Fatalf("failed to pollute: %s", err)
}
}
func TestAllUsers(t *testing.T) {
t.Parallel()
db, closeDb := prepareMySQLDB(t)
defer closeDb()
polluteDb(db, t)
users, err := AllUsersD(db)
if err != nil {
t.Fatal("AllUsers() failed")
}
got := users[0].Email
if got != "myemail#gmail.com" {
t.Errorf("AllUsers().Email = %s; want myemail#gmail.com", got)
}
got1 := len(users)
if got1 != 1 {
t.Errorf("len(AllUsers()) = %d; want 1", got1)
}
}
// Test I'm interested in
func TestAddUser(t *testing.T) {
t.Parallel()
db, closeDb := prepareMySQLDB(t)
defer closeDb()
polluteDb(db, t)
user, err := AddUser(...)
if err != nil {
t.Fatal("AddUser() failed")
}
//how can I clean my database after this?
}
Should I retrieve the last ID inserted in TestAddUser() and just delete that line manually or there's any other way to save my database state and retrieve it after?
As I said I'm new to Go so any other comments on my code or what so ever are strongly appreciated.
The best way is usually to use a transaction, then ROLLBACK, so they are never committed in the first place.
The github.com/DATA-DOG/go-txdb package can help a lot with that.
Final code:
import (
"database/sql"
"os"
"testing"
txdb "github.com/DATA-DOG/go-txdb"
"github.com/romanyx/polluter"
)
//mostly sql tests
func init() {
txdb.Register("txdb", "mysql", "root:root#/betell_rest")
}
func TestAddUser(t *testing.T) {
db, err := sql.Open("txdb", "root:root#/betell_rest")
if err != nil {
t.Fatal(err)
}
defer db.Close()
users, _ := AllUsers(db)
userscount := len(users)
err = AddUser(db, "bla#gmail.com", "pass")
if err != nil {
t.Fatal("AddUser() failed")
}
users, _ = AllUsers(db)
if (userscount + 1) != len(users) {
t.Fatal("AddUser() failed to write in database")
}
}
Note: Also you can pass db into your polluter so you don't affect your database at all.
In my html page, user clicks on Download button after entering the start and end date to download data in csv format.
I have used jquery to get the user inputs from the screen and pass the values to main.go
Now in main.go, I am trying to run a select query to read all the data in database between the two dates that is coming from jquery.
Something like below:
func adminPage(w http.ResponseWriter, r *http.Request) {
dsn := "server=eccdb1677.md3q.ford.com;user id=prx_mdesk_appl;password=******"
db, err := sql.Open("mssql", dsn)
if err != nil {
log.Fatal(err)
}
err = db.Ping()
if err != nil {
log.Fatal(err)
}
defer db.Close()
r.ParseForm()
StartDate := r.FormValue("startdate")
EndDate := r.FormValue("enddate")
rows, _ := db.Query("SELECT * FROM mdesk.dbo.tbl_fdbk WHERE CreateDate BETWEEN StartDate and EndDate")
for rows.Next() {
var (
CDSID string
CreateDate int
Rating int
Comments string
)
err = rows.Scan(&CDSID, &CreateDate, &Rating, &Comments)
if err != nil {
panic(err.Error()) // proper error handling instead of panic in your app
}
file, err := os.Create("reports.csv")
if err != nil {
log.Fatal(err)
}
defer file.Close()
w := csv.NewWriter(file)
err = w.WriteAll(rows)
if err != nil {
log.Fatal("Error writing record to csv:", err)
}
}
}
This code has error in so many levels, but right now I'm focusing more on how to write the select query to read the data between start date and end date.
Any help would be appreciated.
everyone, I have some troubles with postgresql in golang.
I have an sql file (database.sql), and before starting my server I want to exec some command, it look's like that
CREATE TABLE forums (
id BIGSERIAL primary key,
slug TEXT NOT NULL UNIQUE,
title TEXT,
author TEXT references users(login),
threads BIGINT DEFAULT 0,
posts BIGINT DEFAULT 0
);
I know, that I should use db.Exec(request), but i have many requests ("CREATE TABLE user" and others...)
I have no idea, how to do that
Help, and thanks a lot!
You can read the file's contents into a string and pass that to Exec.
query, err := ioutil.ReadFile("path/to/database.sql")
if err != nil {
panic(err)
}
if _, err := db.Exec(query); err != nil {
panic(err)
}
If your database.sql is formated in such a way, or it contains queries that break db.Exec, then you could use os/exec together with psql (if it's installed on the machine on which the code is being run).
cmd := exec.Command("psql", "-d", "database_name", "-f", "path/to/database.sql")
stderr, err := cmd.StderrPipe()
if err != nil {
panic(err)
}
if err := cmd.Start(); err != nil {
panic(err)
}
errout, _ := ioutil.ReadAll(stderr)
if err := cmd.Wait(); err != nil {
fmt.Println(errout)
panic(err)
}
I want to execute a shell script from Go.
The shell script takes standard input and echoes the result.
I want to supply this input from GO and use the result.
What I am doing is:
cmd := exec.Command("python","add.py")
in, _ := cmd.StdinPipe()
But how do I read from in?
Here is some code writing to a process, and reading from it:
package main
import (
"bufio"
"fmt"
"os/exec"
)
func main() {
// What we want to calculate
calcs := make([]string, 2)
calcs[0] = "3*3"
calcs[1] = "6+6"
// To store the results
results := make([]string, 2)
cmd := exec.Command("/usr/bin/bc")
in, err := cmd.StdinPipe()
if err != nil {
panic(err)
}
defer in.Close()
out, err := cmd.StdoutPipe()
if err != nil {
panic(err)
}
defer out.Close()
// We want to read line by line
bufOut := bufio.NewReader(out)
// Start the process
if err = cmd.Start(); err != nil {
panic(err)
}
// Write the operations to the process
for _, calc := range calcs {
_, err := in.Write([]byte(calc + "\n"))
if err != nil {
panic(err)
}
}
// Read the results from the process
for i := 0; i < len(results); i++ {
result, _, err := bufOut.ReadLine()
if err != nil {
panic(err)
}
results[i] = string(result)
}
// See what was calculated
for _, result := range results {
fmt.Println(result)
}
}
You might want to read/write from/to the process in different goroutines.
I'd like to be able to evaluate my queries inside my app, which is in Go and using the github.com/lib/pq driver. Unfortunately, neither the [lib/pq docs][1] nor the [database/sql][2] docs seem to say anything about this, and nothing in the database/sql interfaces suggests this is possible.
Has anyone found a way to get this output?
Typical EXPLAIN ANALYZE returns several rows, so you can do it with simple sql.Query. Here is an example:
package main
import (
"database/sql"
"fmt"
_ "github.com/lib/pq"
"log"
)
func main() {
db, err := sql.Open("postgres", "user=test dbname=test sslmode=disable")
if err != nil {
log.Fatal(err)
}
defer db.Close()
rows, err := db.Query("EXPLAIN ANALYZE SELECT * FROM accounts ORDER BY slug")
if err != nil {
log.Fatal(err)
}
for rows.Next() {
var s string
if err := rows.Scan(&s); err != nil {
log.Fatal(err)
}
fmt.Println(s)
}
if err := rows.Err(); err != nil {
log.Fatal(err)
}
}