postgres中的"$ 1"或附近的golang语法错误

Question

我正在尝试使用sql模块执行查询.

var from string = "2015-03-01 00:00:00"    
rows, err := db.Query("select time, val from table where " +
                              "time >= extract(epoch from timestamp with time zone $1)::int4 " +
                              "and time < extract(epoch from timestamp with time zone '2015-03-01 00:15:10')::int4 " +
                              "order by time asc",from)

但是我得到了错误

pq: syntax error at or near "$1"

如果我直接输入epoch值,那么查询将起作用,并且当我在没有任何变量的情况下尝试它时查询工作,即查询硬编码.那么问题是什么？

Answer 1

你说得对$1和?.

它抱怨语法无效的原因$1是因为类型转换.这样说:

rows, err := db.Query("select time, val from table where " +
                          "time >= extract(epoch from $1::timestamp with time zone)::int4 " +
                          "and time < extract(epoch from timestamp with time zone '2015-03-01 00:15:10')::int4 " +
                          "order by time asc",from)