quickstart/
quickstart.rs

1//! Minimal end-to-end usage of the `sqlrite` crate's public API.
2//!
3//! Run with: `cargo run --example quickstart`
4//!
5//! Walks through:
6//! - Opening an in-memory connection
7//! - Creating a table, inserting rows
8//! - Preparing a SELECT + iterating typed rows
9//! - `get_by_name` + `Option<T>` NULL handling
10//! - A BEGIN / INSERT / ROLLBACK block
11
12use sqlrite::{Connection, Result};
13
14fn main() -> Result<()> {
15    let mut conn = Connection::open_in_memory()?;
16
17    conn.execute("CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT, age INTEGER);")?;
18    conn.execute("INSERT INTO users (name, age) VALUES ('alice', 30);")?;
19    conn.execute("INSERT INTO users (name, age) VALUES ('bob', 25);")?;
20    conn.execute("INSERT INTO users (name, age) VALUES ('charlie', 40);")?;
21
22    println!("All users:");
23    let stmt = conn.prepare("SELECT id, name, age FROM users;")?;
24    let mut rows = stmt.query()?;
25    while let Some(row) = rows.next()? {
26        let id: i64 = row.get_by_name("id")?;
27        let name: String = row.get_by_name("name")?;
28        // `Option<i64>` wraps NULL cleanly — `age` is declared
29        // nullable so the typed accessor surfaces None when absent.
30        let age: Option<i64> = row.get_by_name("age")?;
31        println!(
32            "  {} — {} ({})",
33            id,
34            name,
35            age.map(|a| a.to_string())
36                .unwrap_or_else(|| "NULL".to_string())
37        );
38    }
39
40    // Transactions: BEGIN + INSERT + ROLLBACK leaves the table untouched.
41    conn.execute("BEGIN;")?;
42    conn.execute("INSERT INTO users (name, age) VALUES ('will_vanish', 99);")?;
43    println!("\nMid-transaction row count: {}", count_users(&mut conn)?);
44    conn.execute("ROLLBACK;")?;
45    println!(
46        "Post-rollback row count:   {} (unchanged)",
47        count_users(&mut conn)?
48    );
49
50    Ok(())
51}
52
53fn count_users(conn: &mut Connection) -> Result<usize> {
54    let stmt = conn.prepare("SELECT id FROM users;")?;
55    let rows = stmt.query()?.collect_all()?;
56    Ok(rows.len())
57}
quickstart/quickstart.rs

quickstart/
quickstart.rs
