Is there a way to search all SQL tables by column name? - sql-server

Question

In this answer, you can search all tables for a column by column name.
Say I have a list of columns like this:
DECLARE #columnNames TABLE (Id varchar(30))
INSERT INTO #columnNames
VALUES ('xColumn1Name'), ('xColumn2Name'), ('xColumn3Name')
I want to find all tables that have at least these three columns. Is it possible to do a foreach loop with the code below, or is there a simpler way?
SELECT
COLUMN_NAME AS 'ColumnName', -- this code will get all tables with a column by name #xColumnName, but I would like to pass in a list
TABLE_NAME AS 'TableName'
FROM
INFORMATION_SCHEMA.COLUMNS
WHERE
COLUMN_NAME LIKE '#xColumnName'
ORDER BY
TableName, ColumnName;
The table must have all 3 colums named in the list, and it would be cool if I could filter out tables that do not have a certain column or list of columns

Answer 1

This is a relational division question. There are a few methods to solve this as Joe Celko writes. The common solution is as follows:
DECLARE #columnNames TABLE (Id varchar(30))
INSERT INTO #columnNames
VALUES ('xColumn1Name'), ('xColumn2Name'), ('xColumn3Name')
select t.name
from sys.tables t
join sys.columns c on c.object_id = t.object_id
join #columnNames cn on cn.Id = c.name
group by t.object_id, t.name
having count(*) >=
(select count(*) from #columnNames);
What this says is: give me all tables, where the number of columns which match the list #columnName is the same or more as the number in that list, in other words tehre is a match for every column.

Answer 2

This should get your initial goal.
SELECT
[TableName]
FROM (
SELECT
COLUMN_NAME AS 'ColumnName', -- this code will get all tables with a column by name #xColumnName, but I would like to pass in a list
TABLE_NAME AS 'TableName',
ROW_NUMBER() OVER(PARTITION BY TABLE_NAME ORDER BY COLUMN_NAME) rn
FROM
INFORMATION_SCHEMA.COLUMNS
WHERE
COLUMN_NAME IN ('xColumn1Name', 'xColumn2Name', 'xColumn3Name')
) a
WHERE rn >= 3
For a short explanation, this query will look through the information schema to find any of these columns in a table. The ROW_NUMBER() then basically groups the columns by table. If there are 3 or more results (rn) then all 3 columns are there.
Since it is a sub select, you can also filter the outside select for particular columns if you want.

Answer 3

You could use INTERSECT to combine different result sets. This will give the records that are in all result sets, so in this case, the tables that have all three columns.
SELECT OBJECT_NAME(object_id) AS Table
FROM sys.columns
WHERE name = 'xColumn1Name'
INTERSECT
SELECT OBJECT_NAME(object_id) AS Table
FROM sys.columns
WHERE name = 'xColumn3Name'
INTERSECT
SELECT OBJECT_NAME(object_id) AS Table
FROM sys.columns
WHERE name = 'xColumn3Name'