小编ede*_*ngh的帖子

我使用的是.cargo/config这样的

[target.arm-linux-androideabi]
linker = "/home/rico/android-ndk-r13b/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/arm-linux-androideabi-gcc"

但是/home/rico/android-ndk-r13b是我的NDK_HOME，而不是每个人的NDK_HOME

如何指定使用$NDK_HOME？

就像是：

[target.arm-linux-androideabi]
linker = "$NDK_HOME/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/arm-linux-androideabi-gcc"

我有这个工作代码:

extern crate rusqlite;

use rusqlite::Connection;

fn main() {
    let conn = Connection::open("db.sqlite").unwrap();

    conn.execute("CREATE TABLE toto (size INTEGER NOT NULL DEFAULT 0);", &[]).unwrap();
    conn.execute("INSERT INTO toto(size) VALUES (42);", &[]).unwrap();

    let filter = 0;
    let i: i64 = conn.query_row("SELECT SUM(size) FROM toto", &[], |r| r.get(0)).unwrap();
    println!("Coucou");
    println!("Coucou: {}", i);
}

但如果我改变

"SELECT SUM(size) FROM toto", &[]

至

"SELECT SUM(size) FROM toto WHERE size=?1", &[&filter]

它重新运行,恐慌:

rm db.sqlite
RUST_BACKTRACE=1 cargo run

        Finished dev [unoptimized + debuginfo] target(s) in 0.0 secs
         Running `target/debug/testsqlite` …