Learn to integrate a MySQL database into your Go project using the SQL package for common database operations.
In this guide, you’ll learn how to integrate a MySQL database into your Go project using the SQL package and explore useful methods for common database operations. Follow along to set up your MySQL database, create tables, and execute queries and commands using Go.
Begin by installing MySQL on your system and logging into the MySQL console. Once logged in, create a database named “learning” with the following commands:
Next, create a simple table called data that includes two fields:
An integer id as the primary key.
A name column of type VARCHAR(255) used for storing strings.
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mysql> CREATE TABLE data ( -> id INT PRIMARY KEY, -> name VARCHAR(255) -> );
The data table consists of an id (primary key) and a name field. This structure is suitable for basic storage, demonstration purposes, or further expansion in your applications.
Installing the SQL Package and Setting Up Your Project
To work with MySQL in Go, install the third-party driver package with:
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go get github.com/go-sql-driver/mysql
Create a file named constants.go to store your database connection details as constants. For example, if your database is named “learning” and your username is “root”, define the constants as follows (remember to properly secure sensitive information in a real project):
In your main.go file, import the MySQL driver for its side effects and open a new MySQL connection:
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package mainimport ( "database/sql" "fmt" "log" _ "github.com/go-sql-driver/mysql")func main() { // Form the connection string using the constants defined in constants.go connectionString := fmt.Sprintf("%v:%v@tcp(127.0.0.1:3306)/%v", DbUser, DbPassword, DBName) // Open a database connection using the MySQL driver db, err := sql.Open("mysql", connectionString) checkError(err) defer db.Close() // Continue with further database operations...}
The function sql.Open accepts a driver name and a corresponding data source name. For more details, refer to the Go documentation:
Loop through the result set using the Next and Scan methods to print each row:
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for rows.Next() { var data Data err := rows.Scan(&data.id, &data.name) checkError(err) fmt.Println(data)}
The Next method prepares the next row for reading, while Scan copies the column values into the provided variables. Their official documentation includes:
After validating your SELECT query, insert a new row into the table using the Exec method:
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result, err := db.Exec("INSERT INTO data VALUES(4, 'xyz')")checkError(err)
Retrieve details about the execution, such as the last inserted ID and the number of rows affected:
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// LastInsertId returns the integer generated by the database in response to an INSERT command.lastInsertedId, err := result.LastInsertId()checkError(err)fmt.Println("lastInsertedId:", lastInsertedId)// RowsAffected returns the number of rows affected by an update, insert, or delete.rowsAffected, err := result.RowsAffected()checkError(err)fmt.Println("rowsAffected:", rowsAffected)
Verify the insertion by running another SELECT query and printing the results:
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rows, err = db.Query("SELECT * FROM data")checkError(err)for rows.Next() { var data Data err := rows.Scan(&data.id, &data.name) checkError(err) fmt.Println(data)}
When you run the program, the expected output should be similar to:
With these instructions, you now have a solid understanding of how to integrate MySQL with Go using the SQL package. You have learned to create a database and table, insert data, and perform both SELECT and INSERT operations programmatically. Use these techniques to build robust database operations in your Go projects.
Always ensure that your database credentials are stored securely and consider using environment variables or secret management tools for production applications.