How to get a list column names and datatypes of a table in PostgreSQL?

Question

How can I get a list of column names and datatypes of a table in PostgreSQL using a query?

Answer 1

Here's a version that just queries one table by leveraging the slightly magical ::regclass cast (which I have found is often more performant that joining on pg_class and pg_namespace), has no subqueries, and avoids information_schema (which I have found is often slower, so just as rule, I would avoid if you can)

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
WHERE
    pg_attribute.attrelid = 'my_schema.my_table'::regclass
    AND attnum > 0 
    AND NOT pg_attribute.attisdropped
ORDER BY
    attnum ASC;

Answer 2

SELECT
    column_name,
    data_type
FROM
    information_schema.columns
WHERE
    table_name = 'table_name';

with the above query you can retrieve columns and its datatype.

Answer 3

query = "SELECT column_name FROM information_schema.columns WHERE table_schema = 'schema_name' AND table_name = 'table_name'"
qry = execute(query)
print(qry)

Answer 4

I found @Pratik's answer to be the thing, but it didn't work for me for some reason. I've rewritten it in a more consise, if I may, manner. It's easier to understand, it supports schemas and actually works for me (postgres 15). No joins.

SELECT
    attname AS colname,
    pg_catalog.format_type(atttypid, atttypmod) AS coltype
FROM
    pg_catalog.pg_attribute
WHERE
    attnum > 0 AND
    NOT attisdropped AND
    attrelid = 'your table name'::regclass
ORDER BY
    attnum ASC
;

P.S. It also supports composite types (which I actually needed very much). It would return a string like this: schemaname.tablename.

Answer 5

create a new function to get the table info

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')

Answer 6

 --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
    ;

Answer 7

I was looking for a way to get column names with data types without PSQL cl, directly from pgAdmin 4, and found a workaround. Adding one more option:

right-click desired database > generate ERD(Beta) > Generate SQL(or Alt+Ctrl+S) and pgAdmin 4 will open Query Editor where you can find all tables with column names and data types:

Answer 8

Below will list all the distinct data types of all the table in the provided schema name.

\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

Answer 9

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';

Answer 10

Open psql command line and type :

\d+ table_name

Answer 11

without mentioning schema also you can get the required details Try this query->

select column_name,data_type from information_schema.columns where table_name = 'table_name';

Answer 12

A version that supports finding the column names and types of a table in a specific schema, and uses JOINs without any subqueries

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;

Answer 13

To make this topic 'more complete'.

I required the column names and data types on a SELECT statement (not a table).

If you want to do this on a SELECT statement instead of an actual existing table, you can do the following:

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;

Short explanation, it makes a (temp) table of your select statement, which you can 'call' upon via the query provided by (among others) @a_horse_with_no_name and @selva.

Hope this helps.

Answer 14

Don't forget to add the schema name in case you have multiple schemas with the same table names.

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

or using psql:

\d+ your_schema_name.your_table_name

Answer 15

Updated Pratik answer to support more schemas and nullables:

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'
    );

Answer 16

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)
        );

More info on it : http://www.postgresql.org/docs/9.3/static/catalog-pg-attribute.html