How to retrieve data from temp table in SQL server?

In SQL Server 2016, Microsoft Introduced “Temp tables”. It is a feature that brought the built-in support for gathering information about the data stored in the tables at any time. These temp tables are very useful as they provide rich information about the temporary database in SQL server itself and any change reflected on the table just showing the current data in the current time slot.

In this tutorial, we are going to discuss all the information on the “SQL server temp table”,  How it works? And the following queries:

• Why we use temp table in SQL Server?
• How to create temp table SQL? 
• How to retrieve data from temp table in SQL server?

Why we use temp tables in SQL server?

• A SQL server temp table is designed to store a full history of changes reflected on the data in the database. This record of change in data allows inspection by the admin at any time.
• Temp Tables provides feasibility that lets you process and store intermediate results by using the same update, selection, and join capabilities that you can use with typical SQL tables.
• The temp tables could be very useful in some cases to keep the temporary database in SQL Server. 
• If you are connected to the SQL database server, then the temp table will exist until you close the client or manually destroy the table.

How does a Temp Table Work in SQL Server Database?

Implementation of system-versioning for a table is done with a pair of tables. The first one is a current table, and the other is a history table. In addition to this, for every specific row, the two datetime2 data type period columns are used to define the period of validity.

Workaround to Create a temp table in SQL Server

The below example illustrates how to create a table in SQL:

CREATE TABLE dbo.Users

(

[UserID] int NOT NULL PRIMARY KEY CLUSTERED

, [NAME] nvarchar(100) NOT NULL

, [LEVEL] varchar(100) NOT NULL

, [ValidFrom] datetime2 (2) GENERATED ALWAYS AS ROW START

, [ValidTo] datetime2 (2) GENERATE ALWAYS AS ROW END

, PERIOD FOR SYSTEM_Time (ValidFrom, ValidTo)

)

WITH (SYSTEM_VERSIONING = ON (HISTORY_TABLE = dbo.UserHistory));

Manual method to retrieve data from temp table in SQL Server

Retrieving data with a SQL Server Temp Table is also possible by determining the state of data at a particular time in the past. Restoring records turns out very helpful specifically when the need to recover select or reconstruction of an entire table surfaces. Follow this step-by-step guide to recover the data:

DECLARE @StartDate datetime

DECLARE @EndDate datetime

SET @StartDate=’2020-01-02 00:00:00’

SET @EndDate=’2020-01-09 23:59:59’

SELECT * FROM [Users] FOR system_time between @StartDate and @EndDate

WHERE Name = ‘Pollard’

Once you execute this query, you’ll be given with a time frame informing if the record was deleted or if a change has been made to the table

Automated Solution for-“How to retrieve data from temp table in SQL server”

Our context is all about the temp table and how to retrieve a missing or deleted record. This you can do by analyzing the point of time in the past using the history table successfully. So, now we cannot ignore the corruption issue in SQL Server database also.

It’s frightening to even think of cases when you cannot get the lost data back. These data files can include database objects, a single database table or sub-tables back. Database file corruption, damaged data, broken file, inaccessible files, etc. are some of the many reasons behind such disasters.

In scenarios like so, we recommend using a SQL Recovery software.This utility helps you in getting the corrupt database file back to the normal state.

Wrap Up

This guide gives information about the temp table used in SQL and “How to retrieve data from temp table in SQL Server”. Also, we have prescribed a Professional tool to recover SQL database. If you have any queries regarding any step in this article then feel free to contact me.

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