interactive cat adder
cargo devel CI / cargo CI (push) Failing after 1m46s Details

This commit is contained in:
Christoph J. Scherr 2024-06-25 11:16:16 +02:00
parent c3b9b68af8
commit 99eccc48f8
1 changed files with 121 additions and 22 deletions

View File

@ -1,5 +1,6 @@
use std::io::{BufRead, Write};
use std::path::PathBuf;
use std::{env, fs};
use std::{env, fs, io};
use anyhow::Ok;
/// This demo application uses a sqlite file to store some data. It does *not* use ORM (that would
@ -78,7 +79,7 @@ fn setup(conn: &Connection) -> anyhow::Result<()> {
"CREATE TABLE IF NOT EXISTS {TABLE_CAT} (
id INTEGER PRIMARY KEY,
name TEXT NOT NULL COLLATE NOCASE,
COLOR_ID INTEGER NOT NULL REFERENCES CAT_COLORS(ID)
color_id INTEGER NOT NULL REFERENCES CAT_COLORS(ID)
)"
),
(),
@ -87,43 +88,141 @@ fn setup(conn: &Connection) -> anyhow::Result<()> {
Ok(())
}
// color names are unique, so we use the color name instead of the id because it's easier
fn check_if_color_exists(conn: &Connection, color: &str) -> anyhow::Result<bool> {
let mut stmt = conn.prepare(&format!(
"SELECT EXISTS( SELECT 1 FROM {TABLE_CAT_COLOR} WHERE name = (LOWER(?1)))"
))?;
// we need the return or the temporary result is dropped somehow
#[allow(clippy::needless_return)]
return Ok(stmt
.query([color.to_string()])?
.next()?
.unwrap()
.get::<usize, usize>(0)?
== 1);
}
// note that cat names are not UNIQUE, so we need to use the id instead
fn check_if_cat_exists(conn: &Connection, id: usize) -> anyhow::Result<bool> {
let mut stmt = conn.prepare(&format!(
"SELECT EXISTS( SELECT 1 FROM {TABLE_CAT} WHERE id = (?1))"
))?;
// we need the return or the temporary result is dropped somehow
#[allow(clippy::needless_return)]
return Ok(stmt.query([id])?.next()?.unwrap().get::<usize, usize>(0)? == 1);
}
/// Add a new color to the cat_colors table
///
/// Will fail if the sql fails
///
/// If the color already exists, will return Ok(())
/// If the color already exists, will return Ok(id)
///
/// The table stores the name in lowercase
fn new_color(conn: &Connection, color: &str) -> anyhow::Result<()> {
// check if the color already exists, so we can just try adding a color and not worry if it
// already exists
///
/// Returns the id of the color
fn new_color(conn: &Connection, color: &str) -> anyhow::Result<usize> {
if check_if_color_exists(conn, color)? {
return Ok(get_color_id(conn, color)?);
}
let mut stmt = conn.prepare(&format!(
"SELECT EXISTS( SELECT 1 FROM {TABLE_CAT_COLOR} WHERE name = (?1))"
))?;
if let Some(row) = stmt.query([color.to_string()])?.next()? {
if row.get::<usize, usize>(0)? == 1 {
// the color already exists
return Ok(());
}
};
// do the inserting
conn.execute(
"INSERT INTO cat_colors (name) VALUES (?1)",
&format!("INSERT INTO {TABLE_CAT_COLOR} (name) VALUES (LOWER(?1))"),
[color.to_string()],
)?;
Ok(())
Ok(get_color_id(conn, color)?)
}
fn get_color_id(conn: &Connection, color: &str) -> anyhow::Result<usize> {
Ok(conn.query_row(
&format!("SELECT id FROM {TABLE_CAT_COLOR} WHERE name = (LOWER(?1))"),
[color.to_string()],
|row| row.get::<usize, usize>(0),
)?)
}
fn get_color_by_id(conn: &Connection, id: usize) -> anyhow::Result<String> {
Ok(conn.query_row(
&format!("SELECT name FROM {TABLE_CAT_COLOR} WHERE id = (?1)"),
[id.to_string()],
|row| row.get::<usize, String>(0),
)?)
}
fn new_cat(conn: &Connection, name: &str, color_id: usize) -> anyhow::Result<usize> {
conn.execute(
&format!("INSERT INTO {TABLE_CAT} (name, color_id) VALUES (LOWER(?1), ?2)"),
[name.to_string(), color_id.to_string()],
)?;
Ok(conn.last_insert_rowid() as usize)
}
fn get_cat_color(conn: &Connection, id: usize) -> anyhow::Result<String> {
Ok(conn.query_row(
&format!("SELECT cc.name FROM {TABLE_CAT_COLOR} cc, {TABLE_CAT} c WHERE c.id = (?1) AND c.color_id = cc.id"),
[id.to_string()],
|row| row.get::<usize, String>(0),
)?)
}
fn interactive_add_cat(conn: &Connection) -> anyhow::Result<usize> {
let stdin = io::stdin();
print!("the name of your cat?\n> ");
io::stdout().flush()?;
let mut cat_name: String = String::new();
let _ = stdin.read_line(&mut cat_name)?;
cat_name = cat_name.trim().to_string();
dbg!(&cat_name);
print!("the color of your cat?\n> ");
io::stdout().flush()?;
let mut cat_color: String = String::new();
let _ = stdin.read_line(&mut cat_color)?;
cat_color = cat_color.trim().to_string();
dbg!(&cat_color);
new_color(conn, &cat_color)?;
let cat_id = new_cat(conn, &cat_name, get_color_id(conn, &cat_color)?)?;
assert!(check_if_cat_exists(conn, cat_id)?);
println!("your cat has id {cat_id}");
println!("your cat has color '{}'", get_color_by_id(conn, cat_id)?);
Ok(cat_id)
}
fn main() -> anyhow::Result<()> {
let conn = connect()?;
setup(&conn)?;
new_color(&conn, "black")?;
new_color(&conn, "red")?;
new_color(&conn, "white")?;
let stdin = io::stdin();
let mut buf: String = String::new();
loop {
print!("(A)dd a cat, (F)ind a cat or (E)xit?\n> ");
io::stdout().flush()?;
let _ = stdin.lock().read_line(&mut buf);
buf = buf.trim().to_string();
match buf.as_str() {
"A" => {
interactive_add_cat(&conn)?;
}
"F" => {
todo!()
}
"E" => {
println!("Goodbye");
break;
}
_ => (),
}
buf.clear();
}
Ok(())
}