Macro query

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

The query! macro constructs a value that implements diesel::query_builder::Query – a full SQL query, defined by a format string and binds with the following syntax:

query!("format", binds,*)

The format string introduces binders with curly braces. An empty binder interpolates another query at that position, otherwise the binder is expected to contain a SqlType for a value that will be bound into the query, given a a string which must correspond to a type in the diesel::sql_types module. Bound values or queries to interpolate follow in the order matching their binders in the string:

query!("SELECT * FROM foo WHERE {BigInt} <= cursor AND {}", 5, query!("cursor < {BigInt}", 10))

The above macro invocation will generate the following SQL query:

SELECT * FROM foo WHERE $1 <= cursor AND cursor < $2 -- binds [5, 10]