Inserting data into a temporary table

Handling your tables

When dealing with temporary tables, it's pertinent to have a roadmap for efficient and effective handling.

Schema match and data type verification

Verify that your temporary table schema aligns with that of the selected data. Getting your columns and data types right in the CREATE TABLE phase ensures a smooth data transfer.

SELECT INTO for a frictionless setup

SELECT INTO is your best friend when you want to quickly create a temporary table identical to the scheme of your selected data:

-- Cloning: It's not just for sheep anymore
SELECT UserID, UserName
INTO #TempUser
FROM Users
WHERE Active = 1;
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Strategies for inserting data

Batch insertions

If you're dealing with larger data sets, perform batch insertions using the INSERT INTO...SELECT statement:

-- Forget one by one, let's batch this up!
INSERT INTO #TempUser (UserID, UserName)
SELECT UserID, UserName FROM Users WHERE Active = 1;


Active data filtering

For ultimate control over the specific data being transferred, use a WHERE clause to filter your data like a strainer.

Transactions

Encapsulate your insert operations in a transaction to ensure your database's state remains consistent:

-- For when you wanna make sure no food fights break out at the party
BEGIN TRANSACTION;

-- Insert operations

COMMIT TRANSACTION;
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Error handling and table maintenance

Validating table existence

To avoid pesky runtime errors, ensure a table exists before dropping it:

-- The ghost who lived
IF OBJECT_ID('tempdb..#TempUser') IS NOT NULL
    DROP TABLE #TempUser;


Routine cleanup of temporary tables

Practise the art of dropping unnecessary temporary tables, keeping your database neat and running courtly.

SQL syntax and conventions

Maintain clean code

Using appropriate SQL syntax and formatting boosts readability, making it easy to come back to later.

Consistent naming

Naming conventions for your temp tables should be consistent and make their purpose clear.

Prudent coding

Avoid SELECT * when inserting data. Explicitly naming columns avoids mismatches when table structures change.