Basic structure of PostgreSQL - table

How to be in PostgreSQL Is equivalent to Oracle DESCRIBE TABLE The order of （ Use psql command ）？

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#1 floor

DESCRIBE TABLE Of psql The equivalent term is \\d table .

For more details , Please see the PostgreSQL Manual psql part .

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#2 floor

You can use psql The slash command performs this operation ：

 \d myTable describe table

It also applies to other objects ：

 \d myView describe view \d myIndex describe index \d mySequence describe sequence

source ： faqs.org

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#3 floor

Give it a try （ stay psql In command line tools ）：

\d+ tablename

For more information , Please see the manual  .

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#4 floor

except PostgreSQL The way （\\ d'something' or \\ dt'table' or \\ ds'sequence' etc. ）

SQL Standard way , As shown in the figure ad locum  ：

select column_name, data_type, character_maximum_lengthfrom INFORMATION_SCHEMA.COLUMNS where table_name = '<name of table>';

Many database engines support it .

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#5 floor

If you want to query from instead of psql Get it , Then you can query the directory schema . This is a complex query that performs this operation ：

SELECT      f.attnum AS number,      f.attname AS name,      f.attnum,      f.attnotnull AS notnull,      pg_catalog.format_type(f.atttypid,f.atttypmod) AS type,      CASE          WHEN p.contype = 'p' THEN 't'          ELSE 'f'      END AS primarykey,      CASE          WHEN p.contype = 'u' THEN 't'          ELSE 'f'    END AS uniquekey,    CASE        WHEN p.contype = 'f' THEN g.relname    END AS foreignkey,    CASE        WHEN p.contype = 'f' THEN p.confkey    END AS foreignkey_fieldnum,    CASE        WHEN p.contype = 'f' THEN g.relname    END AS foreignkey,    CASE        WHEN p.contype = 'f' THEN p.conkey    END AS foreignkey_connnum,    CASE        WHEN f.atthasdef = 't' THEN d.adsrc    END AS defaultFROM pg_attribute f      JOIN pg_class c ON c.oid = f.attrelid      JOIN pg_type t ON t.oid = f.atttypid      LEFT JOIN pg_attrdef d ON d.adrelid = c.oid AND d.adnum = f.attnum      LEFT JOIN pg_namespace n ON n.oid = c.relnamespace      LEFT JOIN pg_constraint p ON p.conrelid = c.oid AND f.attnum = ANY (p.conkey)      LEFT JOIN pg_class AS g ON p.confrelid = g.oid  WHERE c.relkind = 'r'::char      AND n.nspname = '%s'  -- Replace with Schema name      AND c.relname = '%s'  -- Replace with table name      AND f.attnum > 0 ORDER BY number;

It's very complicated , But it does show you PostgreSQL Function and flexibility of system directory , And you should gradually master pg_catalog ;-). Make sure to change ％s. The first is mode , The second is the table name .

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#6 floor

You can Use the asterisk  \\d *search pattern * To find the table that matches the search pattern you are interested in .

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#7 floor

You can use ：

SELECT attname FROM pg_attribute,pg_class WHERE attrelid=pg_class.oid AND relname='TableName' AND attstattarget <>0; 

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#8 floor

Except for the command line that has been found \\d+ <table_name> , You can also use it info -schema adopt info_schema.columns find information .

SELECT *FROM info_schema.columnsWHERE table_schema = 'your_schema'AND table_name   = 'your_table'

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#9 floor

Use the following SQL sentence

SELECT DATA_TYPE FROM INFORMATION_SCHEMA.COLUMNS WHERE table_name = 'tbl_name' AND COLUMN_NAME = 'col_name'

If you replace tbl_name and col_name, It will show the data type of the specific column you are looking for .

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#10 floor

You can also use the following query to check

Select * from schema_name.table_name limit 0;

Example ： My watch has 2 Column name and password . Provide the following screenshots .

* Use PG admin3

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#11 floor

Use this command \d table namelike \d queuerecords             Table "public.queuerecords"  Column   |            Type             | Modifiers-----------+-----------------------------+----------- id        | uuid                        | not null endtime   | timestamp without time zone | payload   | text                        | queueid   | text                        | starttime | timestamp without time zone | status    | text                        |

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#12 floor

The best way to describe a table , For example, columns , type , Column modifier, etc .

\d+ tablename or \d tablename

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#13 floor

/ dt It's a comma , It lists all the tables that exist in the database . Use
/ d Command and / d + We can get the details of the table . The system will look like
* / d table_name（ or ）\\ d + table_name

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#14 floor

This change of query （ As stated in other answers ） It works for me .

SELECT COLUMN_NAMEFROM information_schema.COLUMNSWHERE TABLE_NAME = 'city';

Here is a detailed introduction ： http : //www.postgresqltutorial.com/postgresql-describe-table/

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#15 floor

I made the following script for getting the table schema .

'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_exprFROM information_schema.columnsWHERE table_schema || '.' || table_name = 'yourschema.yourtable'ORDER BY ordinal_position) column_list;

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#16 floor

stay MySQL in  ,DESCRIBE table_name

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stay PostgreSQL in  ,\\ d table_name

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perhaps , You can use the following long commands ：

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 ExtrasFROM        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.attnameWHERE        c.relname = 'tablename'        AND a.attnum > 0ORDER BY a.attnum

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#17 floor

In postgres \d is used to describe the table structure.e.g. \d schema_name.table_name;this command will provide you the basic info of table such as, columns, type and modifiers.If you want more info about table use\d+ schema_name.table_name;this will give you extra info such as, storage, stats target and description

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#18 floor

To improve another answer SQL Inquire about （ great ！）, This is a modified query . It also includes constraint names , Inherit information and data types decomposed into components （ type , length , precision , Decimal digit ）. It also filters out deleted columns （ The database still exists ）.

SELECT    n.nspname as schema,    c.relname as table,    f.attname as column,      f.attnum as column_id,      f.attnotnull as not_null,    f.attislocal not_inherited,    f.attinhcount inheritance_count,    pg_catalog.format_type(f.atttypid,f.atttypmod) AS data_type_full,    t.typname AS data_type_name,    CASE          WHEN f.atttypmod >= 0 AND t.typname <> 'numeric'THEN (f.atttypmod - 4) --first 4 bytes are for storing actual length of data    END AS data_type_length,     CASE          WHEN t.typname = 'numeric' THEN (((f.atttypmod - 4) >> 16) & 65535)    END AS numeric_precision,       CASE          WHEN t.typname = 'numeric' THEN ((f.atttypmod - 4)& 65535 )    END AS numeric_scale,           CASE          WHEN p.contype = 'p' THEN 't'          ELSE 'f'      END AS is_primary_key,      CASE        WHEN p.contype = 'p' THEN p.conname    END AS primary_key_name,    CASE          WHEN p.contype = 'u' THEN 't'          ELSE 'f'    END AS is_unique_key,    CASE        WHEN p.contype = 'u' THEN p.conname    END AS unique_key_name,    CASE        WHEN p.contype = 'f' THEN 't'        ELSE 'f'    END AS is_foreign_key,    CASE        WHEN p.contype = 'f' THEN p.conname    END AS foreignkey_name,    CASE        WHEN p.contype = 'f' THEN p.confkey    END AS foreign_key_columnid,    CASE        WHEN p.contype = 'f' THEN g.relname    END AS foreign_key_table,    CASE        WHEN p.contype = 'f' THEN p.conkey    END AS foreign_key_local_column_id,    CASE        WHEN f.atthasdef = 't' THEN d.adsrc    END AS default_valueFROM pg_attribute f      JOIN pg_class c ON c.oid = f.attrelid      JOIN pg_type t ON t.oid = f.atttypid      LEFT JOIN pg_attrdef d ON d.adrelid = c.oid AND d.adnum = f.attnum      LEFT JOIN pg_namespace n ON n.oid = c.relnamespace      LEFT JOIN pg_constraint p ON p.conrelid = c.oid AND f.attnum = ANY (p.conkey)      LEFT JOIN pg_class AS g ON p.confrelid = g.oid  WHERE c.relkind = 'r'::char      AND f.attisdropped = false    AND n.nspname = '%s'  -- Replace with Schema name      AND c.relname = '%s'  -- Replace with table name      AND f.attnum > 0 ORDER BY f.attnum;

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#19 floor

This should be the solution ：

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