如何在 PostgreSQL 中获取表的列名和数据类型列表?

问题描述 投票:0回答:14

如何使用查询获取 PostgreSQL 中表的列名和数据类型列表?

sql postgresql sqldatatypes
14个回答
234
投票
SELECT
    column_name,
    data_type
FROM
    information_schema.columns
WHERE
    table_name = 'table_name';

通过上面的查询,您可以得到列及其数据类型


227
投票

打开

psql
命令行并输入:

\d+ table_name

31
投票
SELECT
        a.attname as "Column",
        pg_catalog.format_type(a.atttypid, a.atttypmod) as "Datatype"
    FROM
        pg_catalog.pg_attribute a
    WHERE
        a.attnum > 0
        AND NOT a.attisdropped
        AND a.attrelid = (
            SELECT c.oid
            FROM pg_catalog.pg_class c
                LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
            WHERE c.relname ~ '^(hello world)$'
                AND pg_catalog.pg_table_is_visible(c.oid)
        );

Change the hello world with your table name

关于它的更多信息:http://www.postgresql.org/docs/9.3/static/catalog-pg-attribute.html


25
投票

如果您有多个具有相同表名的模式,请不要忘记添加模式名称。

SELECT column_name, data_type 
FROM information_schema.columns
WHERE table_name = 'your_table_name' AND table_schema = 'your_schema_name';

或使用 psql:

\d+ your_schema_name.your_table_name

19
投票

支持在特定模式中查找表的列名和类型的版本,并使用不带任何子查询的 JOINs

SELECT
    pg_attribute.attname AS column_name,
    pg_catalog.format_type(pg_attribute.atttypid, pg_attribute.atttypmod) AS data_type
FROM
    pg_catalog.pg_attribute
INNER JOIN
    pg_catalog.pg_class ON pg_class.oid = pg_attribute.attrelid
INNER JOIN
    pg_catalog.pg_namespace ON pg_namespace.oid = pg_class.relnamespace
WHERE
    pg_attribute.attnum > 0
    AND NOT pg_attribute.attisdropped
    AND pg_namespace.nspname = 'my_schema'
    AND pg_class.relname = 'my_table'
ORDER BY
    attnum ASC;

8
投票

更新 Pratik 答案以支持更多模式和可空值:

SELECT
    "pg_attribute".attname                                                    as "Column",
    pg_catalog.format_type("pg_attribute".atttypid, "pg_attribute".atttypmod) as "Datatype",

    not("pg_attribute".attnotnull) AS "Nullable"
FROM
    pg_catalog.pg_attribute "pg_attribute"
WHERE
    "pg_attribute".attnum > 0
    AND NOT "pg_attribute".attisdropped
    AND "pg_attribute".attrelid = (
        SELECT "pg_class".oid
        FROM pg_catalog.pg_class "pg_class"
            LEFT JOIN pg_catalog.pg_namespace "pg_namespace" ON "pg_namespace".oid = "pg_class".relnamespace
        WHERE
            "pg_namespace".nspname = 'schema'
            AND "pg_class".relname = 'table'
    );

7
投票
SELECT column_name,data_type 
FROM information_schema.columns 
WHERE
table_name = 'your_table_name' 
AND table_catalog = 'your_database_name' 
AND table_schema = 'your_schema_name';

3
投票

使这个主题“更完整”。

我需要 SELECT 语句(不是表)中的列名和数据类型。

如果您想在 SELECT 语句而不是实际存在的表上执行此操作,您可以执行以下操作:

DROP TABLE IF EXISTS abc;
CREATE TEMPORARY TABLE abc AS
-- your select statement here!
SELECT 
    *
FROM foo
-- end your select statement
;

select column_name, data_type 
from information_schema.columns 
where table_name = 'abc';
DROP IF EXISTS abc;

简短的解释,它为您的选择语句创建了一个(临时)表,您可以通过(以及其他)@a_horse_with_no_name 和@selva 提供的查询“调用”它。

希望这有帮助。


3
投票

我一直在寻找一种方法来直接从 pgAdmin 4 获取具有数据类型的列名而无需 PSQL cl,并找到了解决方法。添加一个选项:

右键单击所需的数据库 > 生成 ERD(Beta) > 生成 SQL(或 Alt+Ctrl+S),pgAdmin 4 将打开查询编辑器,您可以在其中找到具有列名和数据类型的所有表:


3
投票
 --how to get a list column names and datatypes of a table in PostgreSQL?


    SELECT DISTINCT
        ROW_NUMBER () OVER (ORDER BY pgc.relname , a.attnum) as rowid , 
        pgc.relname as table_name ,
        a.attnum as attr,
        a.attname as name,
        format_type(a.atttypid, a.atttypmod) as typ,
        a.attnotnull as notnull, 
        com.description as comment,
        coalesce(i.indisprimary,false) as primary_key,
        def.adsrc as default
    FROM pg_attribute a 
    JOIN pg_class pgc ON pgc.oid = a.attrelid
    LEFT JOIN pg_index i ON 
        (pgc.oid = i.indrelid AND i.indkey[0] = a.attnum)
    LEFT JOIN pg_description com on 
        (pgc.oid = com.objoid AND a.attnum = com.objsubid)
    LEFT JOIN pg_attrdef def ON 
        (a.attrelid = def.adrelid AND a.attnum = def.adnum)
    LEFT JOIN pg_catalog.pg_namespace n ON n.oid = pgc.relnamespace

    WHERE 1=1 
        AND pgc.relkind IN ('r','')
        AND n.nspname <> 'pg_catalog'
        AND n.nspname <> 'information_schema'
        AND n.nspname !~ '^pg_toast'

    AND a.attnum > 0 AND pgc.oid = a.attrelid
    AND pg_table_is_visible(pgc.oid)
    AND NOT a.attisdropped
    ORDER BY rowid
    ;

2
投票

无需提及架构,您也可以获得所需的详细信息 试试这个查询->

选择列名,数据类型 来自 information_schema.columns 其中 table_name = 'table_name';


0
投票

下面将列出提供的模式名称中所有表的所有不同数据类型。

\copy (select distinct data_type, column_name from information_schema.columns where table_name in (SELECT tablename FROM pg_catalog.pg_tables WHERE schemaname != 'pg_catalog' AND schemaname != 'information_schema' and schemaname = '<Your schema name>')) to 'datatypes.csv'  delimiter as ',' CSV header

0
投票

创建一个新函数来获取表信息

CREATE FUNCTION xdesc(in t varchar) RETURNS table(column_name varchar, 
data_type varchar) AS $$
  SELECT column_name, data_type 
  FROM information_schema.columns
WHERE table_name = $1 
$$ LANGUAGE SQL;


select xdesc('rs_rail_job_index')

0
投票

我发现@Pratik 的答案很重要,但由于某种原因它对我不起作用。如果可以的话,我已经以更简洁的方式重写了它。它更容易理解,它支持模式并且实际上对我有用(

postgres 15
)。

SELECT 
    a.attname AS colname,
    pg_catalog.format_type(a.atttypid, a.atttypmod) AS coltype
FROM
    pg_catalog.pg_attribute AS a
WHERE
    a.attnum > 0 AND
    NOT a.attisdropped AND
    a.attrelid = (
        SELECT 
            c.oid AS relid
        FROM
            pg_catalog.pg_class AS c
        WHERE
            c.relname = '<YOUR TABLE NAME GOES HERE>'
            AND c.relnamespace = (
                SELECT 
                  n.oid
                FROM
                  pg_catalog.pg_namespace AS n
                WHERE
                  n.nspname = '<YOUR SCHEMA NAME GOES HERE>'
            )
    )
;

P.S. 它还支持复合类型(我其实非常需要)。它会返回这样的字符串:

schemaname.tablename
.

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