PostgreSQL Support in Go

Internal

• Database Support in Go
• PostgreSQL

Open a Connection

import (
  "database/sql"
  _ "github.com/lib/pq"
)

...

role := "ovidiu"
password := "something"
databaseHost := "localhost"
databaseName := "testdb"
connectionString := fmt.Sprintf("postgres://%s:%s@%s/%s?sslmode=disable", role, password, databaseHost, databaseName)
db, err := sql.Open("postgres", connectionString)
if err != nil {
  ...
}
defer func() {
  if err := db.Close(); err != nil {
    ...
  }
}()

err = db.Ping()
if err != nil {
  ...
}

"postgres://<user>:<password>@<host>/<database-name>?...." is called connection string.

sql.Open() returns a database handle. The implementation maintains a pool of zero or more underlying connections, and it is safe for concurrent use by multiple goroutines.

Create a Table

sql := `CREATE TABLE IF NOT EXISTS TEST ("ID" int, "NAME" varchar(10))`
_, err = db.Exec(sql)
if err != nil {
 ...
}

Delete a Table

sql := `DROP TABLE TEST`
_, err = db.Exec(sql)
if err != nil {
 ...
}

Insert a Row

sql := `INSERT INTO TEST ("ID", "NAME") VALUES (10, 'Bob')`
_, err = db.Exec(sql)
if err != nil {
  ...
}

Update a Row

sql := `UPDATE TEST SET "ID"=$1 WHERE "NAME"=$2`
_, err = db.Exec(sql, 20, "Bob")
if err != nil {
  ...
}

Delete a Row

sql := `DELETE FROM TEST WHERE "ID"=$1`
_, err = db.Exec(sql, 20)
if err != nil {
  ...
}

Query

sql := `SELECT "ID", "NAME" FROM TEST`
rows, err := db.Query(sql)
if err != nil {
  ...
}
defer rows.Close()
for rows.Next() {
  var id int
  var name string
  err = rows.Scan(&id, &name)
  if err != nil {
    ...
  }
}