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SET @tab = 'tableName'

SET @field1 = (SELECT field1 FROM '+@tab+' WHERE colName IS NULL)

I'm getting this error:

Must declare the table variable "@tab".

I need to set the result on @field1

Robert Columbia
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Sergio Paiva
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    Possible duplicate of [Table name as variable](https://stackoverflow.com/questions/2838490/table-name-as-variable) – Jacob H Mar 12 '18 at 20:07
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    Which database? – C.Champagne Mar 12 '18 at 20:08
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    You have to use dynamic SQL in any database. The specific syntax varies by database. – Gordon Linoff Mar 12 '18 at 20:21
  • Which [DBMS](https://en.wikipedia.org/wiki/DBMS) are you using? "SQL" is just a query language, not the name of a specific database product. Please dd the tag for the database product you are using `postgresql`, `oracle`, `db2`, `sql-server`, ... –  Mar 12 '18 at 21:57
  • Tag properly!!!! Which dbms is this???? It's useless if someone gives you a solution to the wrong dbms. – Eric Mar 12 '18 at 22:12
  • Thanks for all help. I'm using SQL Server. This is a small part of a transact sql. – Sergio Paiva Mar 13 '18 at 00:05

1 Answers1

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For a SQL Server database, use EXECUTE sp_executesql to run the dynamic sql you setup. (Notice the correct placement of the quotes compared to your post).

SET @tab = 'tableName'
SET @field1 = 'SELECT field1 FROM ' + @tab + ' WHERE colName IS NULL'
EXECUTE sp_executesql @field1

However, to save the return value you should look into defining OUTPUT as shown in this answer: https://stackoverflow.com/a/3840771/9392034

Daryl Bagley
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