rovaughn / go-sqlite-lite

SQLite driver for the Go programming language

go-sqlite-lite

go-sqlite-lite is a SQLite driver for the Go programming language. It is designed with the following goals in mind.

• Lightweight - Most methods should be little more than a small wrapper around SQLite C functions.
• Performance - Where possible, methods should be available to allow for the highest peformance possible.
• Understandable - You should always know what SQLite functions are being called and in what order.
• Unsurprising - Connections, PRAGMAs, transactions, bindings, and stepping should work out of the box exactly as you would expect with SQLite.
• Debugable - When you encounter a SQLite error, the SQLite documentation should be relevant and relatable to the Go code.
• Ergonomic - Where it makes sense, convenient compound methods should exist to make tasks easy and to conform to Go standard interfaces.

Most database drivers include a layer to work nicely with the Go database/sql interface, which introduces connection pooling and behavior differences from pure SQLite. This driver does not include a database/sql interface.

Getting started

import "github.com/bvinc/go-sqlite-lite/sqlite3"

Acquiring a connection

conn, err := sqlite3.Open("mydatabase.db")
if err != nil {
	...
}
defer conn.Close()

Executing SQL

err = conn.Exec(`CREATE TABLE student(name STRING, age INTEGER)`)
if err != nil {
	...
}
// Exec can optionally bind parameters
err = conn.Exec(`INSERT INTO student VALUES (?, ?)`, "Bob", 18)
if err != nil {
	...
}

Using Prepared Statements

stmt, err := conn.Prepare(`INSERT INTO student VALUES (?, ?)`)
if err != nil {
	...
}
defer stmt.Close()

// Bind the arguments
err = stmt.Bind("Bill", 18); err != nil {
	...
}
// Step the statement
hasRow, err := stmt.Step()
if err != nil {
	...
}
// Reset the statement
err = stmt.Reset()
if err != nil {
	...
}

Using Prepared Statements Conveniently

stmt, err := conn.Prepare(`INSERT INTO student VALUES (?, ?)`)
if err != nil {
	...
}
defer stmt.Close()

// Exec binds arguments, steps the statement to completion, and always resets the statement
err = stmt.Exec("John", 19)
if err != nil {
	...
}

Using Queries Conveniently

// Prepare can prepare a statement and optionally also bind arguments
stmt, err := conn.Prepare(`SELECT name, age FROM student WHERE age = ?`, 18)
if err != nil {
	...
}
defer stmt.Close()

for {
	hasRow, err := stmt.Step()
	if err != nil {
		...
	}
	if !hasRow {
		// The query is finished
		break
	}

	// Use Scan to access column data from a row
	var name string
	var age int
	err = stmt.Scan(&name, &age)
	if err != nil {
		...
	}
	fmt.Println("name:", name, "age:", age)
}
// Remember to Reset the statement if you would like to Bind new arguments and reuse the prepared staement

Advanced Features

• Binding parameters to statements using SQLite named parameters.
• SQLite Blob Incremental IO API.
• SQLite Online Backup API.
• RawString and RawBytes can be used to reduce copying between Go and SQLite. Please use with caution.

Credit

This project begain as a fork of https://github.com/mxk/go-sqlite/

FAQ

• Why is there no database/sql interface?

If a database/sql interface is required, please use https://github.com/mattn/go-sqlite3 . In my experience, using a database/sql interface with SQLite is painful. Connection pooling causes unnecessary overhead and weirdness. Transactions using Exec("BEGIN") don't work as expected. Your connection does not correspond to SQLite's concept of a connection. PRAGMA commands do not work as expected. When you hit SQLite errors, such as locking or busy errors, it's difficult to discover why since you don't know which connection received which SQL and in what order.

• What are the differences betwen this driver and the mxk/go-sqlite driver?

This driver was forked from mxk/go-sqlite-driver. It hadn't been maintained in years and used an ancient version of SQLite. A large number of features were removed, reworked, and renamed. A lot of smartness and state was removed. It is now much easier to upgrade to newer versions of SQLite since the codec feature was removed. The behavior of methods now lines up closely with the behavior of SQLite's C API.

• Is it thread safe?

go-sqlite-lite is as thread safe as SQLite. SQLite with this driver is compiled with -DSQLITE_THREADSAFE=2 which is Multi-thread mode. In this mode, SQLite can be safely used by multiple threads provided that no single database connection is used simultaneously in two or more threads. This applies to goroutines. A single database conneciton should not be used simultaneously between two goroutines.

It is safe to use separate connection instances concurrently, even if they are accessing the same database file. For example:

// ERROR (without any extra synchronization)
c, _ := sqlite3.Open("sqlite.db")
go use(c)
go use(c)

// OK
c1, _ := sqlite3.Open("sqlite.db")
c2, _ := sqlite3.Open("sqlite.db")
go use(c1)
go use(c2)

Consult the SQLite documentation for more information.

https://www.sqlite.org/threadsafe.html

• How do I pool connections for handling HTTP requests?

Opening new connections is cheap and connection pooling is generally unnecessary for SQLite. I would recommend that you open a new connection for each request that you're handling. This ensures that each request is handled separately and the normal rules of SQLite database/table locking apply.

If you've decided that pooling connections provides you with an advantage, it would be outside the scope of this package and something that you would need to implement and ensure works as needed.

License

This project is licensed under the BSD license.