How do I return the SQL data types from my query?

user_99919 0
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I've a SQL query that queries an enormous (as in, hundreds of views/tables with hard-to-read names like CMM-CPP-FAP-ADD) database that I don't need nor want to understand. The result of this query needs to be stored in a staging table to feed a report.

I need to create the staging table, but with hundreds of views/tables to dig through to find the data types that are being represented here, I have to wonder if there's a better way to construct this table.

Can anyone advise how I would use any of the SQL Server 2008 tools to divine the source data types in my SQL 2000 database?

As a general example, I want to know from a query like:

SELECT Auth_First_Name, Auth_Last_Name, Auth_Favorite_Number 
FROM Authors

Instead of the actual results, I want to know that:

Auth_First_Name is char(25)
Auth_Last_Name is char(50)
Auth_Favorite_Number is int

I'm not interested in constraints, I really just want to know the data types.

sql-server-2008 tsql sql-server sql
13 Answers

For SQL Server 2012 and above: If you place the query into a string then you can get the result set data types like so:

DECLARE @query nvarchar(max) = 'select 12.1 / 10.1 AS [Column1]';
EXEC sp_describe_first_result_set @query, null, 0;
user_157030
user_42638970

I use a simple case statement to render results I can use in technical specification documents. This example does not contain every condition you will run into with a database, but it gives you a good template to work with.

SELECT
     TABLE_NAME          AS 'Table Name',
     COLUMN_NAME         AS 'Column Name',
     CASE WHEN DATA_TYPE LIKE '%char'
          THEN DATA_TYPE + '(' + CONVERT(VARCHAR, CHARACTER_MAXIMUM_LENGTH) + ')'
          WHEN DATA_TYPE IN ('bit', 'int', 'smallint', 'date')
          THEN DATA_TYPE
          WHEN DATA_TYPE = 'datetime'
          THEN DATA_TYPE + '(' + CONVERT(VARCHAR, DATETIME_PRECISION) + ')'
          WHEN DATA_TYPE = 'float'
          THEN DATA_TYPE
          WHEN DATA_TYPE IN ('numeric', 'money')
          THEN DATA_TYPE + '(' + CONVERT(VARCHAR, NUMERIC_PRECISION) + ', ' + CONVERT(VARCHAR, NUMERIC_PRECISION_RADIX) + ')'
     END                 AS 'Data Type',
     CASE WHEN IS_NULLABLE = 'NO'
          THEN 'NOT NULL'
          ELSE 'NULL'
     END                 AS 'PK/LK/NOT NULL'
FROM INFORMATION_SCHEMA.COLUMNS 
ORDER BY 
     TABLE_NAME, ORDINAL_POSITION
user_116672590

Checking data types. The first way to check data types for SQL Server database is a query with the SYS schema table. The below query uses COLUMNS and TYPES tables:

    SELECT C.NAME AS COLUMN_NAME,
       TYPE_NAME(C.USER_TYPE_ID) AS DATA_TYPE,
       C.IS_NULLABLE,
       C.MAX_LENGTH,
       C.PRECISION,
       C.SCALE
FROM SYS.COLUMNS C
JOIN SYS.TYPES T
     ON C.USER_TYPE_ID=T.USER_TYPE_ID
WHERE C.OBJECT_ID=OBJECT_ID('your_table_name');

In this way, you can find data types of columns.

user_103458230

This easy query return a data type bit. You can use this thecnic for other data types:

select CAST(0 AS BIT) AS OK

user_36397200
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