dblink

I am using dblink to move certain data between databases. Everything is save and sound but I am wondering if there is a more convenient way to define the column definition list of a dblink query result. I can do something like this: SELECT * FROM dblink('dbname=remote', 'select * from test') AS t1(id integer, data text); The tables I'm interacting with have the same schema definition in both databases (remote & local). I was thinking of something like: SELECT * FROM dblink('dbname=remote', 'select * from test') AS t1 LIKE public.test; Or: SELECT * FROM dblink('dbname=remote', 'select * from

习惯了Oracle的Dblink带来的便捷，我们来看一下PostgreSQL的DBLINK，该工具需要编译安装一下使用，倒也不是很复杂。 DB版本：9.1.3 1.编译安装 [postgres @localhost dblink]$ pwd /home/postgres/postgresql-9.1.3/contrib/dblink [postgres @localhost dblink]$ make make -C ../../src/interfaces/libpq all make[1]: Entering directory `/home/postgres/postgresql-9.1.3/src/interfaces/libpq' make[1]: Nothing to be done for `all'. make[1]: Leaving directory `/home/postgres/postgresql-9.1.3/src/interfaces/libpq' [postgres @localhost dblink]$ make install make -C ../../src/interfaces/libpq all make[1]: Entering directory `/home/postgres/postgresql-9.1.3/src

In Postgres, you can link to your other databases using dblink , but the syntax is very verbose. For example you can do: SELECT * FROM dblink ( 'dbname=name port=1234 host=host user=user password=password', 'select * from table' ) AS users([insert each column name and its type here]); Is there any way to do this faster? Maybe pre-define the connections? I noticed that Postgres has a new create foreign table function for connecting to a MySQL database. It has a simpler syntax than dblink . Could I use that? In PostgreSQL 8.4 and later, you can use the foreign data wrapper functionality to

Related Link: String literals and escape characters in postgresql Here is my error: ERROR: type "e" does not exist Here is my query: SELECT * FROM dblink('host=theHostName port=1234 dbname=theDBName user=theUser password=thePassword', E'SELECT field_1, CASE WHEN field_2 IS NOT NULL THEN \'inactive\' ELSE \'active\' END AS field_status FROM the_table ') AS linkresults(field_1 varchar(20),field_2 varchar(8)) If I use double quotes, remove the backslash escape for the single quotes and remove the E before the SELECT statement SELECT * FROM dblink('host=theHostName port=1234 dbname=theDBName user

在之前的两篇文章中，章郎虫分别介绍了 dblink 和 postgres_fdw 两个扩展。今天我在这里初略地说下使用dblink和postgres_fdw后的实际感受和区别。 postgres_fdw远程可写功能是9.3版本出来后才新加的，而dblink也可以在以前的postgresql版本中使用。在使用过程中，我把postgres_fdw安装在9.3，dblink安装在9.2.4，而远程连接的都是9.2.4版本的数据库。 首先在安装方面基本都差不多，可以用create extension dblink和create extension postgres_fdw分别安装。 然后比较他们的使用方法。在开始使用dblink之前，首先需要连接远程数据库，然后按照格式编写sql进行查询等操作。这里需要注意，在sql中需要把远程表的字段和类型在本地重新命名，不然sql会报错。这个章郎虫在一开始使用的时候觉得很不方便，而且如果每次查询一张表都要在sql中命名字段和类型其实是很糟糕的，不过幸好可以配置视图把sql“封装”起来。 1 select dblink_connect('myconn', 'host=XXX.XXX.XXX.XXX port=XX dbname=postgres user=myname password=mypassword'); 2 select * from

I am trying to fetch data from remote db by using dblink through function but getting an error "query has no destination for result data". I am using plpgsql language to do the same. Function : CREATE OR REPLACE FUNCTION fun() RETURNS text AS $$ begin select dblink_connect( 'port=5432 dbname=test user=postgres password=****'); WITH a AS ( SELECT * FROM dblink( 'SELECT slno,fname,mname,lname FROM remote_tbl' ) AS t (slno int, fname text, mname text, lname text) ) , b AS ( INSERT INTO temptab1 SELECT slno, name FROM a ) , c AS ( INSERT INTO temptab2 SELECT slno, name FROM a ) INSERT INTO