SQL Server table variables not supported | SELECT columnName FROM @table

[cdandoy]

SQL Server supports storing data in table variables which are in-memory variants to temporary tables:

SELECT columnName FROM @table

https://docs.microsoft.com/en-us/sql/t-sql/data-types/table-transact-sql?view=sql-server-ver15#examples

[cdandoy]

Here are a couple of use cases:

DECLARE @tableName TABLE (id INT);

INSERT INTO @tableName VALUES (1);
UPDATE @tableName SET id=2;
UPDATE t SET id=3 FROM @tableName AS t;
SELECT * FROM @tableName;
DELETE FROM @tableName;
DELETE t FROM @tableName as t;


-- not valid:
-- SELECT @tableName.* FROM @tableName;
-- SELECT 1 INTO @tableName;
-- TRUNCATE TABLE @tableName;
-- CREATE INDEX idx ON @tableName(id);