sql

The sql module opens SQL databases and runs queries over an integer handle. SQLite, Postgres, and MySQL/MariaDB are supported through bundled pure-Go drivers. Import it with import sql.

sql.open picks the driver from the connection string:

":memory:" → in-memory SQLite
"file.db" / "/path/to/file.db" → on-disk SQLite
"postgres://user:pass@host:5432/dbname" (or postgresql://) → Postgres
"mysql://user:pass@host:3306/dbname" → MySQL/MariaDB

It returns an int handle, or -1 on error. Placeholder syntax differs by driver: SQLite and MySQL use ?, while Postgres uses $1, $2, … The rest of the API works identically across drivers.

Functions

Function	Signature	Description
`open`	`sql.open(connStr: string) → int`	open a database; returns a handle or `-1`
`close`	`sql.close(handle: int) → bool`	close the database (rolls back any open tx); true if the handle existed
`exec`	`sql.exec(handle: int, query: string, params?: any[]) → object`	run a statement; returns `{rowsAffected, lastInsertId}`
`query`	`sql.query(handle: int, query: string, params?: any[]) → object[]`	run a SELECT; returns an array of row objects keyed by column name
`queryOne`	`sql.queryOne(handle: int, query: string, params?: any[]) → object`	first row as an object, or void if no rows
`queryValue`	`sql.queryValue(handle: int, query: string, params?: any[]) → any`	first column of the first row, or void if no rows
`transaction`	`sql.transaction(handle: int, fn) → bool`	run `fn(handle)` inside BEGIN/COMMIT; rolls back if `fn` errors or returns `false`

Row objects from query / queryOne have one field per selected column, with values typed as int, float, string, bool, or void (NULL). transaction does not support nesting.

Example

import sql

let db = sql.open(":memory:")
if db < 0 {
    println("failed to open database")
    return
}

sql.exec(db, "CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT, age INT)")

// Insert with placeholders (SQLite/MySQL use ?, Postgres uses $1)
let res = sql.exec(db, "INSERT INTO users (name, age) VALUES (?, ?)", ["Ada", 36])
println("inserted id: " + toString(res.lastInsertId))

// Read rows back
let rows = sql.query(db, "SELECT id, name FROM users WHERE age > ?", [30])
for row in rows {
    println(toString(row.id) + ": " + row.name)
}

let count = sql.queryValue(db, "SELECT COUNT(*) FROM users")
println("total: " + toString(count))

// Transaction: returning false rolls back
sql.transaction(db, fn(h) {
    sql.exec(h, "UPDATE users SET age = age + 1 WHERE name = ?", ["Ada"])
    return true
})

sql.close(db)

Standard library · View as Markdown · llms-full.txt