PostgreSQL 查询 table 列注释？

Question

我已将 MySQL 数据库迁移到 PostgreSQL 并将查询

SHOW FULL COLUMNS FROM schema_name.table_name;

替换为等效的 Postgres ,

SELECT * FROM information_schema.columns WHERE table_schema = 'schema_name' and table_name = 'table_name';

其中 returns 列及其属性但是 'Comment' 属性在 MySQL 查询中返回，在 PostgreSQL 查询中未返回。

有没有办法查询与每个 column_name 关联的评论？

Answer 1

这个怎么样：

select col_description((table_schema||'.'||table_name)::regclass::oid, ordinal_position) as column_comment
, * from information_schema.columns 
WHERE table_schema = 'schema_name' 
and table_name = 'table_name';

Answer 2

你知道这显示在 \dt+ 下你可以逆向工程 psql 用 -E

-E --echo-hidden Echo the actual queries generated by \d and other backslash commands. You can use this to study psql's internal operations. This is equivalent to setting the variable ECHO_HIDDEN to on.

psql -d test -E -c'\dt+ foo'
********* QUERY **********
SELECT n.nspname as "Schema",
  c.relname as "Name",
  CASE c.relkind WHEN 'r' THEN 'table' WHEN 'v' THEN 'view' WHEN 'm' THEN 'materialized view' WHEN 'i' THEN 'index' WHEN 'S' THEN 'sequence' WHEN 's' THEN 'special' WHEN 'f' THEN 'foreign table' END as "Type",
  pg_catalog.pg_get_userbyid(c.relowner) as "Owner",
  pg_catalog.pg_size_pretty(pg_catalog.pg_table_size(c.oid)) as "Size",
  pg_catalog.obj_description(c.oid, 'pg_class') as "Description"
FROM pg_catalog.pg_class c
     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE c.relkind IN ('r','s','')
      AND n.nspname !~ '^pg_toast'
  AND c.relname ~ '^(foo)$'
  AND pg_catalog.pg_table_is_visible(c.oid)
ORDER BY 1,2;
**************************

你可以在这里看到psql显示的所有信息。俗话说，授人以渔... ?

PostgreSQL 查询 table 列注释？

PostgreSQL query for table column comments?

mysql

postgresql

database-migration