Statements for pgc:execute/2,3: a text, a text with its parameters, or a template.

pgc_statement:new(~"select 1"),
pgc_statement:new({~"select $1::int4", [42]}).

A template is a list of text and tokens. A {parameter, Info} token becomes a placeholder bound to its value. Parameters with the same key share a placeholder, and type adds a cast. An {identifier, Info} token becomes a quoted identifier.

Statement = pgc_statement:new([
    ~"select * from ", {identifier, #{value => ~"user"}},
    ~" where id = ", {parameter, #{key => id, value => 42, type => int8}},
    ~" or parent_id = ", {parameter, #{key => id, value => 42}}
]),
~"select * from \"user\" where id = ($1::int8) or parent_id = $1" =
    iolist_to_binary(pgc_statement:text(Statement)),
[42] = pgc_statement:parameters(Statement).