How do you list the primary key of a SQL Server table?

Question

Simple question, how do you list the primary key of a table with T-SQL? I know how to get indexes on a table, but can't remember how to get the PK.

user_2194 · Answer

SELECT Col.Column_Name from 
    INFORMATION_SCHEMA.TABLE_CONSTRAINTS Tab, 
    INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE Col 
WHERE 
    Col.Constraint_Name = Tab.Constraint_Name
    AND Col.Table_Name = Tab.Table_Name
    AND Constraint_Type = 'PRIMARY KEY'
    AND Col.Table_Name = ''

footndale_2526 · Answer

Is using MS SQL Server you can do the following:

--List all tables primary keys
select * from information_schema.table_constraints
where constraint_type = 'Primary Key'

You can also filter on the table_name column if you want a specific table.

user_12861 · Answer

I like the INFORMATION_SCHEMA technique, but another I've used is: exec sp_pkeys 'table'

user_8119464 · Answer

I am telling a simple Technic which I follow

SP_HELP 'table_name'

run this code as query. Mention your table name at place of table_name for which you want to know Primary Key (don't forget the single quotes). The result will show like attached Image. Hope it will help you

user_17746 · Answer

The system stored procedure sp_help will give you the information. Execute the following statement:

execute sp_help table_name

Admin · Answer

SELECT t.name AS 'table', i.name AS 'index', it.xtype,

(SELECT c.name FROM syscolumns c INNER JOIN sysindexkeys k 
    ON k.indid = i.indid 
        AND c.colid = k.colid 
        AND c.id = t.id 
        AND k.keyno = 1 
        AND k.id = t.id)
    AS 'column1',

(SELECT c.name FROM syscolumns c INNER JOIN sysindexkeys k 
    ON k.indid = i.indid 
        AND c.colid = k.colid 
        AND c.id = t.id 
        AND k.keyno = 2 
        AND k.id = t.id)
    AS 'column2',

(SELECT c.name FROM syscolumns c INNER JOIN sysindexkeys k 
    ON k.indid = i.indid 
        AND c.colid = k.colid 
        AND c.id = t.id 
        AND k.keyno = 3
        AND k.id = t.id)
    AS 'column3',

(SELECT c.name FROM syscolumns c INNER JOIN sysindexkeys k 
    ON k.indid = i.indid 
        AND c.colid = k.colid 
        AND c.id = t.id 
        AND k.keyno = 4
        AND k.id = t.id)
    AS 'column4',

(SELECT c.name FROM syscolumns c INNER JOIN sysindexkeys k 
    ON k.indid = i.indid 
        AND c.colid = k.colid 
        AND c.id = t.id 
        AND k.keyno = 5
        AND k.id = t.id)
    AS 'column5',

(SELECT c.name FROM syscolumns c INNER JOIN sysindexkeys k 
    ON k.indid = i.indid 
        AND c.colid = k.colid 
        AND c.id = t.id 
        AND k.keyno = 6
        AND k.id = t.id)
    AS 'column6',

(SELECT c.name FROM syscolumns c INNER JOIN sysindexkeys k 
    ON k.indid = i.indid 
        AND c.colid = k.colid 
        AND c.id = t.id 
        AND k.keyno = 7
        AND k.id = t.id)
    AS 'column7',

(SELECT c.name FROM syscolumns c INNER JOIN sysindexkeys k 
    ON k.indid = i.indid 
        AND c.colid = k.colid 
        AND c.id = t.id 
        AND k.keyno = 8 
        AND k.id = t.id)
    AS 'column8',

(SELECT c.name FROM syscolumns c INNER JOIN sysindexkeys k 
    ON k.indid = i.indid 
        AND c.colid = k.colid 
        AND c.id = t.id 
        AND k.keyno = 9 
        AND k.id = t.id)
    AS 'column9',

(SELECT c.name FROM syscolumns c INNER JOIN sysindexkeys k 
    ON k.indid = i.indid 
        AND c.colid = k.colid 
        AND c.id = t.id 
        AND k.keyno = 10
        AND k.id = t.id)
    AS 'column10',

FROM sysobjects t
    INNER JOIN sysindexes i ON i.id = t.id 
    INNER JOIN sysobjects it ON it.parent_obj = t.id AND it.name = i.name

WHERE it.xtype = 'PK'
ORDER BY t.name, i.name

user_171240 · Answer

Thanks Guy.

With a slight variation I used it to find all the primary keys for all the tables.

SELECT A.Name,Col.Column_Name from 
    INFORMATION_SCHEMA.TABLE_CONSTRAINTS Tab, 
    INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE Col ,
    (select NAME from dbo.sysobjects where xtype='u') AS A
WHERE 
    Col.Constraint_Name = Tab.Constraint_Name
    AND Col.Table_Name = Tab.Table_Name
    AND Constraint_Type = 'PRIMARY KEY '
    AND Col.Table_Name = A.Name

user_919643 · Answer

Below query will list primary keys of particular table:

SELECT DISTINCT
    CONSTRAINT_NAME AS [Constraint],
    TABLE_SCHEMA AS [Schema],
    TABLE_NAME AS TableName
FROM
    INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE
    TABLE_NAME = 'mytablename'

user_1051237 · Answer

If you are looking to do your own ORM or generate code from a given table, then this might be what you are looking form:

declare @table varchar(100) = 'mytable';

with cte as
(
    select 
        tc.CONSTRAINT_SCHEMA
        , tc.CONSTRAINT_TYPE
        , tc.TABLE_NAME
        , ccu.COLUMN_NAME
        , IS_NULLABLE
        , DATA_TYPE
        , CHARACTER_MAXIMUM_LENGTH
        , NUMERIC_PRECISION
    from 
        INFORMATION_SCHEMA.TABLE_CONSTRAINTS tc 
        inner join INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE ccu on tc.TABLE_NAME=ccu.TABLE_NAME  and tc.TABLE_SCHEMA=ccu.TABLE_SCHEMA
        inner join information_schema.COLUMNS c on ccu.COLUMN_NAME=c.COLUMN_NAME and ccu.TABLE_NAME=c.TABLE_NAME and ccu.TABLE_SCHEMA=c.TABLE_SCHEMA
    where 
        tc.table_name=@table
        and 
        ccu.CONSTRAINT_NAME=tc.CONSTRAINT_NAME
    union 
    select TABLE_SCHEMA,'COLUMN', TABLE_NAME, COLUMN_NAME, IS_NULLABLE, DATA_TYPE,CHARACTER_MAXIMUM_LENGTH, NUMERIC_PRECISION from INFORMATION_SCHEMA.COLUMNS where TABLE_NAME=@table
    and COLUMN_NAME not in (select COLUMN_NAME from INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE where TABLE_NAME = @table)
)
select 
    cast(iif(CONSTRAINT_TYPE='PRIMARY KEY',1,0) as bit) PrimaryKey
    ,cast(iif(CONSTRAINT_TYPE='FOREIGN KEY',1,0) as bit) ForeignKey
    ,cast(iif(CONSTRAINT_TYPE='COLUMN',1,0) as bit) NotKey
    ,COLUMN_NAME
    ,cast(iif(is_nullable='NO',0,1) as bit) IsNullable
    , DATA_TYPE
    , CHARACTER_MAXIMUM_LENGTH
    , NUMERIC_PRECISION 
from 
    cte 
order by 
    case CONSTRAINT_TYPE 
        when 'PRIMARY KEY' then 1 
        when 'FOREIGN KEY' then 2 
        else 3 end
    , COLUMN_NAME

Here is what the result would look like:

    
     
      PrimaryKey
      ForeignKey
      NotKey
      COLUMN_NAME
      IsNullable
      DATA_TYPE
      CHARACTER_MAXIMUM_LENGTH
      NUMERIC_PRECISION
     
     
      1
      0
      0
      LectureNoteID
      0
      int
      NULL
      10
     
     
      0
      1
      0
      LectureId
      0
      int
      NULL
      10
     
     
      0
      1
      0
      NoteTypeID
      0
      int
      NULL
      10
     
     
      0
      0
      1
      Body
      0
      nvarchar
      -1
      NULL
     
     
      0
      0
      1
      DisplayOrder
      0
      int
      NULL
      10

user_5974407 · Answer

If Primary Key and type needed, this query may be useful:

SELECT L.TABLE_SCHEMA, L.TABLE_NAME, L.COLUMN_NAME, R.TypeName
FROM(
    SELECT COLUMN_NAME, TABLE_NAME, TABLE_SCHEMA
    FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
    WHERE OBJECTPROPERTY(OBJECT_ID(CONSTRAINT_SCHEMA + '.' + QUOTENAME(CONSTRAINT_NAME)), 'IsPrimaryKey') = 1
)L
LEFT JOIN (
    SELECT
    OBJECT_NAME(c.OBJECT_ID) TableName ,c.name AS ColumnName ,t.name AS TypeName
    FROM sys.columns AS c
    JOIN sys.types AS t ON c.user_type_id=t.user_type_id
)R ON L.COLUMN_NAME = R.ColumnName AND L.TABLE_NAME = R.TableName

user_5315581 · Answer

For a comma separated list of primary key columns for a given TableName and Schema:

Select distinct SUBSTRING ( stuff(( select distinct ',' + [COLUMN_NAME] 
                                    from INFORMATION_SCHEMA.KEY_COLUMN_USAGE  
                                    where OBJECTPROPERTY(OBJECT_ID(CONSTRAINT_SCHEMA + '.' + QUOTENAME(CONSTRAINT_NAME)), 'IsPrimaryKey') = 1  
                                    AND TABLE_NAME = 'TableName' AND TABLE_SCHEMA = 'Schema'  
                                    order by 1 FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'),1,0,'' ) 
                            ,2,9999)

Austin_Salonen_4068 · Answer

Give this a try:

SELECT
    CONSTRAINT_CATALOG AS DataBaseName,
    CONSTRAINT_SCHEMA AS SchemaName,
    TABLE_NAME AS TableName,
    CONSTRAINT_Name AS PrimaryKey
FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS 
WHERE CONSTRAINT_TYPE = 'Primary Key' and Table_Name = 'YourTable'

user_8206858 · Answer

May I suggest a more accurate simple answer to the original question below

SELECT 
KEYS.table_schema, KEYS.table_name, KEYS.column_name, KEYS.ORDINAL_POSITION 
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE keys
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS CONS 
    ON cons.TABLE_SCHEMA = keys.TABLE_SCHEMA 
    AND cons.TABLE_NAME = keys.TABLE_NAME 
    AND cons.CONSTRAINT_NAME = keys.CONSTRAINT_NAME
WHERE cons.CONSTRAINT_TYPE = 'PRIMARY KEY'

Notes:

Some of the answers above are missing a filter for just primary key columns!
I'm using below in a CTE to join to a larger column listing to provide the metadata from a source to feed BIML generation of staging tables and SSIS code

user_1699472 · Answer

I found this from my friend, very effective if you are looking for all the table's primary keys under particular schema.

SELECT tc.constraint_name AS IndexName,tc.table_name AS TableName,tc.table_schema
AS SchemaName,kc.column_name AS COLUMN_NAME
FROM information_schema.table_constraints tc,information_schema.key_column_usage kc
WHERE tc.constraint_type = 'PRIMARY KEY' AND kc.table_name = tc.table_name AND kc.table_schema = tc.table_schema
AND kc.constraint_name = tc.constraint_name AND tc.table_schema=''

user_653281 · Answer

Probably the simplest solution :)

EXEC sp_pkeys YourTable

user_11402186 · Answer

If you need it in Oracle it is so simple.

SELECT `Constraint_Name`
  FROM `All_Constraints`
 WHERE `Constraint_Type` = `'P'`
   AND `Owner` = `'your schema here';`

How do you list the primary key of a SQL Server table?

27 Answers