Retrieving Primary Key, Identity column, and specific name column from Database tables - sql

Question

I need to get primary key (if present), identity (if present), and column named 'ID' (if present) from every table in selected database. I got SQL query to do the work, but query returns records where Primary Key sometimes has both "No" and "Yes" values. Thus, resulting in multiple rows of data, so I used word DISTINCT to remove duplicates. I am assuming this is due to Indexes defined on some columns.
How would it be possible to fix this?
SQL query used:
SELECT DISTINCT
object_name(i.object_id) [Table],
c.name [Column],
IIF(i.is_primary_key = 1, 'Yes', 'No') [PK],
IIF(c.is_identity = 1, 'Yes', 'No') [Identity],
IIF(UPPER(c.name) = 'ID', 'Yes', 'No') [Named ID]
FROM sys.indexes i
INNER JOIN sys.columns c ON c.object_id = i.object_id
INNER JOIN sys.identity_columns idc ON idc.object_id = c.object_id AND idc.column_id = c.column_id
WHERE
i.is_primary_key = 1 OR c.is_identity = 1 OR c.name = 'ID'
ORDER BY [Table];

Answer 1

You can do the following query, however you could get results where multiple columns form the primary key like the following:
because of something like:
ALTER TABLE [derived].[LocationParameterMedium]
ADD CONSTRAINT [PK_LocationParameterMedium] PRIMARY KEY CLUSTERED ([CycleID] ASC, [LocationID] ASC, [ParameterID] ASC, [MediumID] ASC)
GO
Which can be fixed by rolling up the columns into a single column, the following link explains how to roll-up columns into a single column
Query:
SELECT
OBJECT_SCHEMA_NAME(t.object_id) AS [Schema], -- Incase there is mulple schemas and same table name
t.name AS [Table],
c.name AS [Column],
IIF((SELECT 1
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE keyCU
WHERE keyCU.COLUMN_NAME = c.name
AND keyCU.TABLE_SCHEMA = OBJECT_SCHEMA_NAME(t.object_id)
AND keyCU.TABLE_NAME = t.name
AND OBJECTPROPERTY(OBJECT_ID(keyCU.CONSTRAINT_SCHEMA + '.' + QUOTENAME(keyCU.CONSTRAINT_NAME)), 'IsPrimaryKey') = 1) = 1, 'Yes', 'No') [PK],
IIF(c.is_identity = 1, 'Yes', 'No') [Identity],
IIF(c.name = 'ID', 'Yes', 'No') [Named ID]
FROM sys.tables AS t
LEFT JOIN sys.columns AS c
ON t.object_id = c.object_id
AND (c.is_identity = 1
OR c.name = 'ID'
OR EXISTS ( SELECT 1
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE keyCU
WHERE keyCU.COLUMN_NAME = c.name
AND keyCU.TABLE_SCHEMA = OBJECT_SCHEMA_NAME(t.object_id)
AND keyCU.TABLE_NAME = t.name
AND OBJECTPROPERTY(OBJECT_ID(keyCU.CONSTRAINT_SCHEMA + '.' + QUOTENAME(keyCU.CONSTRAINT_NAME)), 'IsPrimaryKey') = 1
)
)
---- To exclude tables where there is no PK, identity, or column name = 'ID'
--WHERE c.name IS NOT NULL

Answer 2

You are using sys.indexes. A table can have multiple indexes and a column can be used multiple indexes. What your query is telling you is that the column is used in the PK index and also in another index (which is not the PK index).
Also your query is excluding all columns that are not in an index.
Start with sys.columns and use outer joins instead. Object id is the id of the table, not of the column, so you need index_columns aswell.
SELECT DISTINCT
object_name(c.object_id) [Table],
c.name [Column],
i.is_primary_key,
case i.is_primary_key when 1 then 'Yes' else 'No'end [PK],
case c.is_identity when 1 then 'Yes' else 'No'end [Identity],
case c.name when 'ID' then 'Yes' else 'No'end [Named ID]
FROM sys.columns c
left join sys.index_columns ic on c.column_id = ic.column_id and c.object_id = ic.object_id
left JOIN sys.indexes i ON i.index_id = ic.index_id and c.object_id = i.object_id and i.is_primary_key= 1
left JOIN sys.identity_columns idc ON idc.object_id = c.object_id AND idc.column_id = c.column_id
WHERE i.is_primary_key = 1 OR c.is_identity = 1 OR c.name = 'ID'
ORDER BY [Table];

Answer 3

For anyone needing something similar in the future, I adopted version of Peter's answer (including advice from Sean Lange to use sys.tables):
SELECT
t.name AS [Table],
c.name AS [Column],
CASE i.is_primary_key WHEN 1 THEN 'Yes' ELSE 'No' END [PK],
CASE idc.is_identity WHEN 1 THEN 'Yes' ELSE 'No' END [Identity],
CASE c.name WHEN 'ID' THEN 'Yes' ELSE 'No' END [Named ID]
FROM
sys.tables t
LEFT JOIN sys.columns c ON c.object_id = t.object_id
LEFT JOIN sys.identity_columns idc ON idc.object_id = t.object_id AND idc.column_id = c.column_id AND idc.is_identity = 1
LEFT JOIN sys.index_columns ic ON ic.object_id = t.object_id AND ic.column_id = c.column_id
LEFT JOIN sys.indexes i ON i.object_id = t.object_id AND i.index_id = ic.index_id AND i.is_primary_key = 1
WHERE t.type = 'U' AND (idc.is_identity = 1 OR i.is_primary_key = 1 OR c.name = 'ID')
ORDER BY t.name, c.name;