SQL server query to get the list of columns in a table along with Data types, NOT NULL, and PRIMARY KEY constraints

Question

I need to write a query on SQL server to get the list of columns in a particular table, its associated data types (with length) and if they are not null. And I have managed to do this much.

But now i also need to get, in the same table, against a column - TRUE if that column is a primary key.

How do i do this?

My expected output is:

Column name | Data type | Length | isnull | Pk

Solution 1

To avoid duplicate rows for some columns, use user_type_id instead of system_type_id.

SELECT 
    c.name 'Column Name',
    t.Name 'Data type',
    c.max_length 'Max Length',
    c.precision ,
    c.scale ,
    c.is_nullable,
    ISNULL(i.is_primary_key, 0) 'Primary Key'
FROM    
    sys.columns c
INNER JOIN 
    sys.types t ON c.user_type_id = t.user_type_id
LEFT OUTER JOIN 
    sys.index_columns ic ON ic.object_id = c.object_id AND ic.column_id = c.column_id
LEFT OUTER JOIN 
    sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id
WHERE
    c.object_id = OBJECT_ID('YourTableName')

Just replace YourTableName with your actual table name - works for SQL Server 2005 and up.

In case you are using schemas, replace YourTableName by YourSchemaName.YourTableName where YourSchemaName is the actual schema name and YourTableName is the actual table name.

Solution 2

The stored procedure sp_columns returns detailed table information.

exec sp_columns MyTable

Solution 3

You could use the query:

select COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, 
       NUMERIC_PRECISION, DATETIME_PRECISION, 
       IS_NULLABLE 
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME='TableName'

to get all the metadata you require except for the Pk information.

Solution 4

In SQL 2012 you can use:

EXEC sp_describe_first_result_set N'SELECT * FROM [TableName]'

This will give you the column names along with their properties.

Solution 5

Try this:

select COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, IS_NULLABLE 
from INFORMATION_SCHEMA.COLUMNS IC
where TABLE_NAME = 'tablename' and COLUMN_NAME = 'columnname'

View more solutions

Comments

[DOK]

Could you show the code you have already?

[Shrayas]

i did that :) But i need the PK too :|

[Shrayas]

well. It doesnt give me the required result :(

[Andrew Savinykh]

This gives wrong lengths for the nvarchar, etc type of columns. It gives the byte length that is twice as much as the length in the column type.

[marc_s]

Those lengths are not wrong - it does give the byte length - that's the maximum possible length in bytes... if you want to calculate space etc., that's the length you want to get....

[Nathan Jones]

I'm getting an error when I try to run this: Server 'CLM', Line 5 Incorrect syntax near the keyword 'precision'.

[Nathan Jones]

I'm running it in SQL Server 2000. I changed all of the field names to their SQL Server 2000 counterparts, and it works now.

[marc_s]

@NathanJones: as I already said in the answer - this script is for SQL Server 2005 and newer only!

[Nathan Jones]

Sorry about that! I didn't read that last part until after I started having trouble. Thanks for your help!

[Artemix]

How does your answer differ from the one posted by Ajadex? Both answers do not return Primary Key information.

[Ed Pecyna]

You may want to throw a DISTINCT clause in there also... I got some duplicate column names in my results.

[Ed Pecyna]

ADDENDUM: Even with DISTINCT you can end up with 2 records for 1 column.

[Our Man in Bananas]

+1 ahh, but now I want to get the data in my table alongside the column datatypes... any thoughts

[hobs]

Worked well for me in Django using pyodbc and FreeTDS on fedora when I needed to augment the simple manage.py inspectdb command. Here's the code

[marc_s]

@Terry: the catalog views return the max length in bytes (not in characters) - already been talked about, see 2nd and 3rd comments ...

[Santhos]

It works on views as well (no surprise) and it also works on Azure SQL.

[Doc Holiday]

Works great for me SQL Server 2012 :)

[Leonardo Marques de Souza]

msdn.microsoft.com/pt-br/library/ms189813(v=sql.120).aspx sp_fkeys sp_pkeys

[Leonardo Marques de Souza]

exec sp_pkeys exec sp_fkeys

[Rafa Barragan]

He ask for a query, but you're right this way allows you to see all the info.

[Toxantron]

Please use indentation instead of inline Markup and add some explaination to your answer.

[Ivan]

WHERE c.object_id = OBJECT_ID('YourTableName') .... I needed WHERE c.object_id = OBJECT_ID('MySchema.MyTableName') and then everything worked fine.

[molerus]

Ok, with that awesome query i get the byte length for every column. I need to know how many characters fit in nvarchar columns, can i simply divide maxlength between 2 to find the answer? I have a nvarchar(10) column, maxlength returns 20, can i consider that a single character always needs 2 bytes to be stored in ddbb? What does the byte per character number depend on? Thanks

[marc_s]

@molerus: yes - nvarchar (and nchar) are always 2 byte = 1 character

[Razvan Socol]

This query returns duplicated columns if you have multiple indexes involving the same column. To fix it, replace the last two joins with the following: LEFT OUTER JOIN sys.index_columns ic LEFT OUTER JOIN sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id ON ic.object_id = c.object_id AND ic.column_id = c.column_id AND i.is_primary_key=1

[Akshay Chawla]

this query has saved lots of time for me, as my tables has 60+ columns. Also this worked perfectly.

[Martijn Pieters]

if this question has already been answered, flag the post as a duplicate.

[reggaeguitar]

Why ORDER BY 2?

[yeOldeDataSmythe]

I found that I still received some duplicates with the left outer joins. Once I removed them and the Primary Key column, the duplicates disappeared. Wrapping this within a function would allow you to insert these rows into the return table and then update if the primary key is still needed. The table returns quickly.

[dyslexicanaboko]

I think it is a bit deceptive to say that max_length is your length when it absolutely isn't. Pretty much every query I have found makes this false assumption. I don't understand why there isn't a separate column for just giving me the length. Instead this is what I found that I have to use: docs.microsoft.com/en-us/sql/t-sql/functions/… which has the same problem apparently.

[dyslexicanaboko]

You can say that's obvious but it isn't. It should be explicitly stated and already available to the user. Why should I have to do this obvious calculation? Just give me the same length I see in my editor and when I define my schema.

[dyslexicanaboko]

You are making my point for me - IT DOES DO THAT. I am looking at my editor and I see 255, I query the column and it is returning 510. I don't want to see 510 I want to see 255 which is what I inputted. I don't want to be tasked with dividing it by 2 which is pretty annoying. That's not what I entered.

[marc_s]

@dyslexicanaboko: you're right - and I'm baffled - I was convinced it showed the length in characters - not bytes. Probably never realized since I always use VARCHAR and hardly ever Unicode ......

[dyslexicanaboko]

It's all good man - you are very active on SO, so thank you for taking the time to respond to me.

[George Menoutis]

the DDL Name is SO useful for dynamic-sql that creates tables! Thanks!!

[Allen]

your condition of Constraint should be the other way around.

[Abdullah Al Mamun]

And how to know the foreign Keys in the table with the query

[marc_s]

@AbdullahAlMamun: check out the sys.foreign_keys catalog view

[Sylvain Gantois]

answer should be updated to handle schemas (for instance 2 tables with same name in different schemas)

[Mitch Wheat]

@marc_s : unfortuntaely, this has a flaw if the Primary key column(s) appear in other indexes: create table dbo.DummyTable ( id int not null identity(0,1) primary key, Msg varchar(80) null ); create index NC_DummyTable_id ON DummyTable(id);

[Ram]

using 'information_schema.columns' we can view info for all tables columns including viewing table name and schema.

[Mitch Wheat]

stackoverflow.com/questions/2418527/…

[Uttam]

This works for Excel files opened with OPENROWSET as well while many other solutions don't. Thank you.

[Daniel]

If using this, note that MyTable really is just the table name, not the schema. To filter to a schema, add it as a second parameter: exec sp_columns 'MyTable', 'MySchema'