声明动态日期表名称以供查询参考

Question

I am simply trying to research/obtain logic for how to dynamically (Ie GETDATE() function) call tables which are created with date stamps.

For example, I have tables in the database listed as such:

• [dbo].[CLAIM_01.01.2018]
• [dbo].[CLAIM_01.15.2018]
• [dbo].[CLAIM_01.31.2018]

The logic I am thinking of would behave similar to that of setting a variable for a data element in a table (Ie SET @IMPORT_DATE = DATEADD(MONTH, DATEDIFF(MONTH, 0, GETDATE())-1, 0))

Instead I would like to write a declare statement that would scan the database for a table name based on date stamp parameters. In other words, I am looking for logic that would reference the most RECENT/MAX date of the table generation (in the above examples, 1/31/2018)

Please let me know if I can/should provide greater specificity for this request.

Thank you for any assistance!

Answer 1

You could use something like this. Select the user tables of the database and convert the suffix to a date.

DECLARE @maxTable VARCHAR(255)
SET @maxTable = (
    SELECT TOP (1) name
    FROM (
        SELECT  name
            ,   DATEFROMPARTS(RIGHT(name,4), SUBSTRING(name, 7, 2), SUBSTRING(name, 10, 2)) AS dTable
        FROM    sys.tables WHERE type = 'U'
        ) AS sub
    ORDER BY sub.dTable DESC)

SELECT @maxTable

Result

CLAIM_01.31.2018

Answer 2

If you have to keep this schema, you can select for a pattern in sys.tables , like:

DECLARE @IMPORT_DATE nvarchar(10) = CONVERT(nvarchar(10), GETDATE(), 4)
SELECT schemas.name + '.' + tables.name 
FROM sys.tables INNER JOIN sys.schemas 
ON tables.schema_id = schemas.schema_id 
WHERE tables.name LIKE '%' + @IMPORT_DATE + '%'

That being said, wouldn't it make more sense to have a date field in a single, static CLAIM table?