Struct mysql::conn::Stmt
[−]
[src]
pub struct Stmt<'a> {
// some fields omitted
}Mysql prepared statement.
Methods
impl<'a> Stmt<'a>
fn params_ref(&self) -> Option<&[Column]>
Returns a slice of a Columns which represents
Stmt's params if any.
fn columns_ref(&self) -> Option<&[Column]>
Returns a slice of a Columns which represents
Stmt's columns if any.
fn column_index<T: AsRef<str>>(&self, name: T) -> Option<usize>
Returns index of a Stmt's column by name.
fn execute<'s, T: Into<Params>>(&'s mut self, params: T) -> MyResult<QueryResult<'s>>
Executes prepared statement with parameters passed as a [Into<Params>] implementor.
let mut stmt0 = pool.prepare("SELECT 42").unwrap(); let mut stmt1 = pool.prepare("SELECT ?").unwrap(); let mut stmt2 = pool.prepare("SELECT ?, ?").unwrap(); let mut stmt13 = pool.prepare("SELECT ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?").unwrap(); // It is better to pass params as a tuple when executing statements of arity <= 12 for row in stmt0.execute(()).unwrap() { let cell = from_row::<u8>(row.unwrap()); assert_eq!(cell, 42u8); } // just do not forget about trailing comma in case of arity = 1 for row in stmt1.execute((42,)).unwrap() { let cell = from_row::<u8>(row.unwrap()); assert_eq!(cell, 42u8); } // If you don't want to lose ownership of param, then you should pass it by reference let word = "hello".to_string(); for row in stmt2.execute((&word, &word)).unwrap() { let (cell1, cell2) = from_row::<(String, String)>(row.unwrap()); assert_eq!(cell1, "hello"); assert_eq!(cell2, "hello"); } // If you want to execute statement of arity > 12, then you can pass params as &[&ToValue]. let params: &[&ToValue] = &[&1, &2, &3, &4, &5, &6, &7, &8, &9, &10, &11, &12, &13]; for row in stmt13.execute(params).unwrap() { let row: Vec<u8> = row.unwrap().unwrap().into_iter().map(from_value::<u8>).collect(); assert_eq!(row, vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]); } // but be aware of implicit copying, so if you have huge params and do not care // about ownership, then better to use plain Vec<Value>. let mut params: Vec<Value> = Vec::with_capacity(13); for i in 1..14 { params.push(repeat('A').take(i * 1000).collect::<String>().into()); } for row in stmt13.execute(params).unwrap() { let row = row.unwrap(); let row: Vec<String> = row.unwrap().into_iter().map(from_value::<String>).collect(); for i in 1..14 { assert_eq!(row[i-1], repeat('A').take(i * 1000).collect::<String>()); } }