以下代碼工作正常。但我想將 array['a', 'b', 'c', 'd', 'e'] 定義為變量。rows, err := db.Query("select colname from (SELECT date, unnest(array['a', 'b', 'c', 'd', 'e']) AS colname, unnest(array[a, b, c, d, e]) AS thing from test1 where date='123') as tester where thing=1;")所以我嘗試使用 github.com/lib/pq 跟蹤代碼。arr1 := []string{"a", "b", "c", "d", "e"} rows, err := db.Query("select colname from (SELECT date, unnest($1) AS colname, unnest($1) AS thing from test1 where date='123') as tester where thing=1;", pq.Array(arr1))但是得到像“pq: function unnest(unknown) is not unique”這樣的錯誤。表結(jié)構(gòu)和示例數(shù)據(jù)--test=# \d+ test1 Table "public.test1" Column | Type | Modifiers | Storage | Stats target | Description --------+-----------------------+-----------+----------+--------------+------------- a | character varying(10) | | extended | | b | character varying(10) | | extended | | c | character varying(10) | | extended | | d | character varying(10) | | extended | | e | character varying(10) | | extended | | date | character varying(10) | | extended | | test=# select * from test1 ; a | b | c | d | e | date ---+---+---+---+---+------ 3 | 1 | 3 | 2 | 3 | 124 3 | 3 | 2 | 2 | 1 | 125 1 | 2 | 2 | 1 | 3 | 126 1 | 2 | 3 | 2 | 3 | 127 1 | 1 | 2 | 2 | 3 | 123(5 rows)基本上我想要在任何特定日期具有值“1”的列名稱（a、b、c、d 或 e）。
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慕姐4208626
TA貢獻(xiàn)1852條經(jīng)驗(yàn) 獲得超7個贊
我猜這pq.Array是給你一個字符串形式的 PostgreSQL 數(shù)組，所以你最終得到這樣的東西：
unnest('{a,b,c,d,e}')并且 PostgreSQL 不確定它應(yīng)該如何解釋該字符串，因此對unnest(unknown). 您應(yīng)該能夠添加一個顯式類型轉(zhuǎn)換來清除問題：
unnest($1::text[]) -- PostgreSQL-specific casting syntax unnest(cast($1 as text[])) -- Standard casting syntax
你最終會得到這樣的結(jié)果：
rows, err := db.Query("select colname from (SELECT date, unnest($1::text[]) AS colname, unnest($1) AS thing from test1 where date='123') as tester where thing=1;", pq.Array(arr1))- 1 回答
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