Project: YugabyteDB (App Definition and Development / Database)
File: pq.md

title: Go PQ Driver for YSQL headerTitle: Connect an application linkTitle: Connect an app description: Connect a Go application using PQ driver menu: v2.18: identifier: pq-driver parent: go-drivers weight: 420 type: docs <ul class="nav nav-tabs-alt nav-tabs-yb"> <li class="active"> <a href="../yb-pgx/" class="nav-link"> YSQL </a> </li> <li> <a href="../ycql/" class="nav-link"> YCQL </a> </li> </ul> <ul class="nav nav-tabs-alt nav-tabs-yb"> <li > <a href="../yb-pgx/" class="nav-link"> <i class="icon-postgres" aria-hidden="true"></i> YugabyteDB PGX Smart Driver </a> </li> <li > <a href="../pgx/" class="nav-link"> <i class="icon-postgres" aria-hidden="true"></i> PGX Driver </a> </li> <li > <a href="../pq/" class="nav-link active"> <i class="icon-postgres" aria-hidden="true"></i> PQ Driver </a> </li> </ul> The is a popular driver for PostgreSQL. Use the driver to connect to YugabyteDB to execute DMLs and DDLs using the standard `database/sql` package. For Go Applications, most drivers provide database connectivity through the standard `database/sql` API. The following sections break down the example to demonstrate how to perform common tasks required for Go application development using the PQ driver. To start building your application, make sure you have met the . Import the PQ driver package by adding the following import statement in your Go code. ```go import ( _ "github.com/lib/pq" ) ``` To install the package locally, run the following commands: {{< note title="Note">}} Set the environment variable `GO111MODULE` before installing the `lib/pq` package if your Go version is 1.11 or higher. {{< /note >}} ```sh export GO111MODULE=auto go get github.com/lib/pq ``` Go applications can connect to YugabyteDB using the `sql.Open()` function. The `sql` package includes all the functions or structs required for working with YugabyteDB. Use the `sql.Open()` function to create a connection object for the YugabyteDB database. This can be used for performing DDLs and DMLs against the database. The connection details can be specified either as string parameters or via a URL in the following format: ```sh postgresql://username:password@hostname:port/database ``` Code snippet for connecting to YugabyteDB: ```go psqlInfo := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s", host, port, user, password, dbname) // Other connection configs are read from the standard environment variables: // PGSSLMODE, PGSSLROOTCERT, and so on. db, err := sql.Open("postgres", psqlInfo) defer db.Close() if err != nil { log.Fatal(err) } ``` | Parameter | Description | Default | | :-- | :- | : | | user | User connecting to the database | yugabyte | password | User password | yugabyte | host | Hostname of the YugabyteDB instance | localhost | port | Listen port for YSQL | 5433 | dbname | Database name | yugabyte For a YugabyteDB Managed cluster, or a YugabyteDB cluster with SSL/TLS enabled, set the SSL-related environment variables as below at the client side. SSL/TLS is enabled by default for client-side authentication. Refer to for the default and supported modes. ```sh $ export PGSSLMODE=verify-ca $ export PGSSLROOTCERT=~/root.crt # Here, the CA certificate file is downloaded as `root.crt` under home directory. Modify your path

``` | Environment Variable | Description | | :- | :- | | PGSSLMODE | SSL mode used for the connection | | PGSSLROOTCERT | Path to the root certificate on your computer | Create a file called `QuickStart.go` and add the following contents into it: ```go package main import ( "database/sql" "fmt" "log" _ "github.com/lib/pq" ) const ( host = "127.0.0.1" port = 5433 user = "yugabyte" password = "yugabyte" dbname = "yugabyte" ) func main() { psqlInfo := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s", host, port, user, password, dbname) // Other connection configs are read from the standard environment variables: // PGSSLMODE, PGSSLROOTCERT, and so on. db, err := sql.Open("postgres", psqlInfo) if err != nil { log.Fatal(err) } var dropStmt = `DROP TABLE IF EXISTS employee`; if _, err := db.Exec(dropStmt); err != nil { log.Fatal(err) } // The `conn.Exec()` function also returns an `error` object which, // if not `nil`, needs to be handled in your code. var createStmt = `CREATE TABLE employee (id int PRIMARY KEY, name varchar, age int, language varchar)`; if _, err := db.Exec(createStmt); err != nil { log.Fatal(err) } fmt.Println("Created table employee") // Insert data using the conn.Exec() function. var insertStmt string = "INSERT INTO employee(id, name, age, language)" + " VALUES (1, 'John', 35, 'Go')"; if _, err := db.Exec(insertStmt); err != nil { log.Fatal(err) } fmt.Printf("Inserted data: %s\n", insertStmt) // Execute the `SELECT` statement using the function `Query()` on `db` instance. var name string var age int var language string rows, err := db.Query(`SELECT name, age, language FROM employee WHERE id = 1`) if err != nil { log.Fatal(err) } defer rows.Close() fmt.Printf("Query for id=1 returned: "); // Results are returned as `rows` which can be iterated using `rows.next()` method. for rows.Next() { // Use `rows.Scan()` for reading the data. err := rows.Scan(&name, &age, &language) if err != nil { log.Fatal(err) } fmt.Printf("Row[%s, %d, %s]\n", name, age, language) } err = rows.Err() if err != nil { log.Fatal(err) } defer db.Close() } ``` The const values are set to the defaults for a local installation of YugabyteDB. If you're using YugabyteDB Managed, replace the values as follows: host - The host address of your cluster. The host address is displayed on the cluster Settings tab. user - Your YugabyteDB database username. In YugabyteDB Managed, the default user is admin. password - Your YugabyteDB database password. dbname - The name of the YugabyteDB database. The default name is yugabyte. port is set to 5433, which is the default port for the YSQL API. Run the project `QuickStartApp.go` using the following command: ```go go run QuickStartApp.go ``` You should see output similar to the following: ```output Created table employee Inserted data: INSERT INTO employee(id, name, age, language) VALUES (1, 'John', 35, 'Go') Query for id=1 returned: Row[John, 35, Go] ``` Build Go applications using Build Go applications using