SELECT INTO a table variable in T-SQL

Got a complex SELECT query, from which I would like to insert all rows into a table variable, but T-SQL doesn't allow it.

Along the same lines, you cannot use a table variable with SELECT INTO or INSERT EXEC queries. http://odetocode.com/Articles/365.aspx

Short example:

declare @userData TABLE(
                        name varchar(30) NOT NULL,
                        oldlocation varchar(30) NOT NULL
                       )

SELECT name, location
INTO @userData
FROM myTable
    INNER JOIN otherTable ON ...
WHERE age > 30

The data in the table variable would be later used to insert/update it back into different tables (mostly copy of the same data with minor updates). The goal of this would be to simply make the script a bit more readable and more easily customisable than doing the SELECT INTO directly into the right tables. Performance is not an issue, as the rowcount is fairly small and it's only manually run when needed.
...or just tell me if I'm doing it all wrong.

Try something like this:

DECLARE @userData TABLE(
    name varchar(30) NOT NULL,
    oldlocation varchar(30) NOT NULL
);

INSERT INTO @userData (name, oldlocation)
SELECT name, location FROM myTable
INNER JOIN otherTable ON ...
WHERE age > 30;

The purpose of SELECT INTO is (per the docs, my emphasis)

To create a new table from values in another table

But you already have a target table! So what you want is

The INSERT statement adds one or more new rows to a table

You can specify the data values in the following ways:

...

By using a SELECT subquery to specify the data values for one or more rows, such as:
  INSERT INTO MyTable 
 (PriKey, Description)
        SELECT ForeignKey, Description
        FROM SomeView

And in this syntax, it's allowed for MyTable to be a table variable.

You can also use common table expressions to store temporary datasets. They are more elegant and adhoc friendly:

WITH userData (name, oldlocation)
AS
(
  SELECT name, location 
  FROM   myTable    INNER JOIN 
         otherTable ON ...
  WHERE  age>30
)
SELECT * 
FROM   userData -- you can also reuse the recordset in subqueries and joins

You could try using temporary tables...if you are not doing it from an application. (It may be ok to run this manually)

SELECT name, location INTO #userData FROM myTable
INNER JOIN otherTable ON ...
WHERE age>30

You skip the effort to declare the table that way... Helps for adhoc queries...This creates a local temp table which wont be visible to other sessions unless you are in the same session. Maybe a problem if you are running query from an app.

if you require it to running on an app, use variables declared this way :

DECLARE @userData TABLE(
    name varchar(30) NOT NULL,
    oldlocation varchar(30) NOT NULL
);

INSERT INTO @userData
SELECT name, location FROM myTable
INNER JOIN otherTable ON ...
WHERE age > 30;

Edit: as many of you mentioned updated visibility to session from connection. Creating temp tables is not an option for web applications, as sessions can be reused, stick to temp variables in those cases

SELECT INTO a table variable in T-SQL

Related

Recent Posts