/
noconnpool.go
100 lines (90 loc) · 2.2 KB
/
noconnpool.go
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// Example: No connection pool
//
// Setting the pool size to 1, a single session is used at all times. This guarantees USE <object type> <object name>
// changes the current working object and subsequent commands can have the access.
package main
import (
"database/sql"
"flag"
"fmt"
"log"
"os"
"strconv"
"sync"
sf "github.com/snowflakedb/gosnowflake"
)
// getDSN constructs a DSN based on the test connection parameters
func getDSN() (string, *sf.Config, error) {
env := func(k string, failOnMissing bool) string {
if value := os.Getenv(k); value != "" {
return value
}
if failOnMissing {
log.Fatalf("%v environment variable is not set.", k)
}
return ""
}
account := env("SNOWFLAKE_TEST_ACCOUNT", true)
user := env("SNOWFLAKE_TEST_USER", true)
password := env("SNOWFLAKE_TEST_PASSWORD", true)
host := env("SNOWFLAKE_TEST_HOST", false)
port := env("SNOWFLAKE_TEST_PORT", false)
protocol := env("SNOWFLAKE_TEST_PROTOCOL", false)
portStr, _ := strconv.Atoi(port)
cfg := &sf.Config{
Account: account,
User: user,
Password: password,
Host: host,
Port: portStr,
Protocol: protocol,
}
dsn, err := sf.DSN(cfg)
return dsn, cfg, err
}
func main() {
if !flag.Parsed() {
flag.Parse()
}
dsn, cfg, err := getDSN()
if err != nil {
log.Fatalf("failed to create DSN from Config: %v, err: %v", cfg, err)
}
db, err := sql.Open("snowflake", dsn)
if err != nil {
log.Fatalf("failed to connect. %v, err: %v", dsn, err)
}
// single session
db.SetMaxIdleConns(1)
db.SetMaxOpenConns(1)
defer db.Close()
var wg sync.WaitGroup
n := 10
wg.Add(n)
for i := 0; i < n; i++ {
go func() {
defer wg.Done()
query := "select current_session()"
rows, err := db.Query(query) // no cancel is allowed
if err != nil {
log.Fatalf("failed to run a query. %v, err: %v", query, err)
}
defer rows.Close()
var v int
for rows.Next() {
err := rows.Scan(&v)
if err != nil {
log.Fatalf("failed to get result. err: %v", err)
}
fmt.Printf("Session: %v\n", v)
}
if rows.Err() != nil {
fmt.Printf("ERROR: %v\n", rows.Err())
return
}
}()
}
fmt.Println("Waiting to finish...")
wg.Wait()
fmt.Printf("Congrats! You have successfully!\n")
}