通过以下查询,我们可以获得PostgreSQL中表的列名和数据类型的列表。
Answers:
select column_name,data_type
from information_schema.columns
where table_name = 'table_name';
通过上面的查询,您可以列及其数据类型
geometry(Geometry,[SRID])
),这不会给出正确的答案。
table_catalog = 'my_database'
和table_schema = 'my_schema'
。
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)$'
AND pg_catalog.pg_table_is_visible(c.oid)
);
有关更多信息:http : //www.postgresql.org/docs/9.3/static/catalog-pg-attribute.html
c.relname ~ '^(hello world)$
而不是简单地使用c.relname = 'hello world'
?
更新了Pratik答案以支持更多架构和可为空的内容:
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'
);
一个版本,该版本支持在特定架构中查找表的列名和类型,并使用JOIN而不包含任何子查询
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;
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
;
使该主题“更完整”。
我需要SELECT语句(而不是表)上的列名和数据类型。
如果要在SELECT语句而不是实际的现有表上执行此操作,则可以执行以下操作:
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;
简短的解释是,它创建了一个select语句的(临时)表,您可以通过@a_horse_with_no_name和@selva提供的查询来“调用”该表。
希望这可以帮助。
从information_schema.columns中选择column_name,data_type,其中table_name ='your_table_name'和table_catalog ='your_database_name'和table_schema ='your_schema_name';