如何使用psql命令在PostgreSQL中执行Oracle的DESCRIBE TABLE?


当前回答

这应该是解决方案:

SELECT * FROM information_schema.columns
WHERE table_schema = 'your_schema'
   AND table_name   = 'your_table'

其他回答

与DESCRIBE TABLE等效的psql是\d TABLE。

有关详细信息,请参阅PostgreSQL手册的psql部分。

除了PostgreSQL方式(\d“something”或\dt“table”或\ds“sequence”等)

SQL标准方式,如下所示:

select column_name, data_type, character_maximum_length, column_default, is_nullable
from INFORMATION_SCHEMA.COLUMNS where table_name = '<name of table>';

它受到许多db引擎的支持。

在MySQL中,DESCRIBE table_name


在PostgreSQL中,\d table_name


或者,可以使用以下长命令:

SELECT
        a.attname AS Field,
        t.typname || '(' || a.atttypmod || ')' AS Type,
        CASE WHEN a.attnotnull = 't' THEN 'YES' ELSE 'NO' END AS Null,
        CASE WHEN r.contype = 'p' THEN 'PRI' ELSE '' END AS Key,
        (SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid), '\'(.*)\'')
                FROM
                        pg_catalog.pg_attrdef d
                WHERE
                        d.adrelid = a.attrelid
                        AND d.adnum = a.attnum
                        AND a.atthasdef) AS Default,
        '' as Extras
FROM
        pg_class c 
        JOIN pg_attribute a ON a.attrelid = c.oid
        JOIN pg_type t ON a.atttypid = t.oid
        LEFT JOIN pg_catalog.pg_constraint r ON c.oid = r.conrelid 
                AND r.conname = a.attname
WHERE
        c.relname = 'tablename'
        AND a.attnum > 0

ORDER BY a.attnum

我为get表模式编写了以下脚本。

'CREATE TABLE ' || 'yourschema.yourtable' || E'\n(\n' ||
array_to_string(
array_agg(
'    ' || column_expr
)
, E',\n'
) || E'\n);\n'
from
(
SELECT '    ' || column_name || ' ' || data_type || 
coalesce('(' || character_maximum_length || ')', '') || 
case when is_nullable = 'YES' then ' NULL' else ' NOT NULL' end as column_expr
FROM information_schema.columns
WHERE table_schema || '.' || table_name = 'yourschema.yourtable'
ORDER BY ordinal_position
) column_list;

In postgres\d用于描述表结构。

例如\d schema_name.table_name

该命令将为您提供表的基本信息,如列、类型和修饰符。

如果您想了解更多有关表格使用的信息

\d+ schema_name.table_name

这将为您提供额外的信息,如存储、统计目标和描述