Question

我在数据库T1中有表DB1，在数据库T2中有表DB2，这些表与C_additional中的列T1几乎完全相同{1}}，T2中不存在{1}}。我需要将所有行从T2转移到T1，为我插入的每一行设置一些C_additional值。例如：T1和T2只有一列C1 integer，T1也有C_additional列text }，所以我的代码看起来像这样：

INSERT INTO T1
SELECT 
        C1,
        C_additional='needed_value'
FROM dblink(
    'hostaddr=127.0.0.1 port=5432 dbname=DB2 user=postgres password=postgres', 
    'SELECT * FROM T2')
AS T2_row(C1 integer)

我收到以下错误：

ERROR: column "C_additional" does not exist
SQL state: 42703
Hint: There is a column named "C_additional" in table "T1", but it cannot be referenced from this part of the query.

如何使用SQL进行数据传输，还是应该使用PG / SQL？

Answer 1

您可以在select子句前指定带括号的目标列：

INSERT INTO T1
(c1, c_additional) -- here
SELECT 
        C1,
        'needed_value' -- just select a constant here
FROM dblink(
    'hostaddr=127.0.0.1 port=5432 dbname=DB2 user=postgres password=postgres', 
    'SELECT * FROM T2')
AS T2_row(C1 integer)

Answer 2

你能试试吗？

INSERT INTO T1
SELECT 
        C1,
        'needed_value'
FROM dblink(
    'hostaddr=127.0.0.1 port=5432 dbname=DB2 user=postgres password=postgres', 
    'SELECT * FROM T2')
AS T2_row(C1 integer)

PostgreSQL INSERT FROM SELECT带有附加列

2 个答案: