Question

I have a large SQL database where I need to verify the structure of the tables and columns (not the data itself). So I need to generate a list of all of the tables, then for each table, all of its columns, then for each column, its data type, length/precision, ordinal position, and whether it’s part of the primary key for that table.

I can get most of what I need with the following query:

SELECT TABLE_NAME, ORDINAL_POSITION, COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, NUMERIC_PRECISION, NUMERIC_SCALE
FROM INFORMATION_SCHEMA.COLUMNS

However, I’m not sure how to check whether a column is part of a primary key. Additionally, for those tables where the PK consists of more than one column, I want to know the ordinal position of each column within the key. The information I’ve found so far relates to setting the key rather than reading it.

I’m interested in doing this in both SQL Server and Oracle.

Answer 1

In SQL Server you can do

SELECT K.TABLE_CATALOG, 
       K.TABLE_NAME, 
       K.COLUMN_NAME, 
       K.ORDINAL_POSITION 
FROM   INFORMATION_SCHEMA.KEY_COLUMN_USAGE K 
       INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS TC 
         ON K.TABLE_CATALOG = TC.TABLE_CATALOG 
            AND K.TABLE_SCHEMA = TC.TABLE_SCHEMA 
            AND K.CONSTRAINT_NAME = TC.CONSTRAINT_NAME 
WHERE  TC.CONSTRAINT_TYPE = 'PRIMARY KEY' 

or

SELECT Object_name(C.OBJECT_ID) TABLE_NAME, 
       C.NAME, 
       IC.INDEX_COLUMN_ID 
FROM   SYS.KEY_CONSTRAINTS K 
       INNER JOIN SYS.INDEX_COLUMNS IC 
         ON K.PARENT_OBJECT_ID = IC.OBJECT_ID 
            AND K.UNIQUE_INDEX_ID = IC.INDEX_ID 
       INNER JOIN SYS.COLUMNS C 
         ON IC.OBJECT_ID = C.OBJECT_ID 
            AND IC.COLUMN_ID = C.COLUMN_ID 
WHERE  K.TYPE = 'PK' 

IN ORACLE

SELECT K.OWNER, 
       K.TABLE_NAME, 
       K.INDEX_NAME, 
       C.COLUMN_NAME, 
       C.COLUMN_POSITION 
FROM   ALL_CONSTRAINTS K 
       INNER JOIN ALL_IND_COLUMNS C 
         ON K.OWNER = C.INDEX_OWNER 
            AND K.TABLE_NAME = C.TABLE_NAME 
            AND K.INDEX_NAME = C.INDEX_NAME 
WHERE  K.CONSTRAINT_TYPE = 'P'