Macro map

map!() { /* proc-macro */ }

Maps arguments of the generated database access method into a tuple of SQL arguments.

Examples

Single Argument

let arg = 42;
let args = include_oracle_sql_args::map!(arg => "SELECT " :arg " FROM xxx WHERE x = " :arg " OR y = " :arg " ORDER BY z");
assert_eq!(args, 42);

Exactly 2 Parameters

let a1 = 27;
let a2 = "name";
let args = include_oracle_sql_args::map!(a1 a2 => "SELECT * FROM xxx WHERE a = " :a1 " AND b = " :a2);
assert_eq!(args, (27, "name", ()));

Unique SQL Parameters

let a1 = 31;
let a2 = "text";
let a3 = &["a", "b", "c"];
let args = include_oracle_sql_args::map!(a1 a2 a3 => "UPDATE xxx SET a = " :a1 ", :b = " :a2 " WHERE c IN (" #a3 ")");
assert_eq!(args, (31, "text", &["a", "b", "c"]));

Duplicate SQL Parameters

let id = 19;
let name = "unknown";
let data = 3.14;
let args = include_oracle_sql_args::map!(id name data => "UPDATE xxx SET a = " :name ", b = " :name ", c = " :data " WHERE i = " :id " OR ( x = " :name " AND i != " :id ")");
assert_eq!(args, (
    ("ID",   19),
    ("NAME", "unknown"),
    ("DATA", 3.14),
));

Reordered SQL Parameters

let a1 = 31;
let a2 = "text";
let a3 = &["a", "b", "c"];
let args = include_oracle_sql_args::map!(a1 a2 a3 => "UPDATE xxx SET a = " :a2 ", :b = " :a1 " WHERE c IN (" #a3 ")");
assert_eq!(args, (
    ("A1", 31), 
    ("A2", "text"),
    ("A3", &["a", "b", "c"]),
));

Mutable (OUT) Argument

let id = 101;
let mut name = String::new();
let out_name = &mut name;
let args = include_oracle_sql_args::map!(id out_name => "UPDATE xxx SET x = x || 'X' WHERE i = " :id " RETURN x INTO " :out_name);
assert_eq!(args.0, 101);
assert_eq!(args.2, ());
// emulate output
args.1.push_str("TestX");
assert_eq!(name, "TestX");