How do I add a column to a dynamic table in SQL?

How do I add a column to a dynamic table in SQL?

Adding Columns in #Temp table dynamically:

1. DECLARE @ColName nvarchar(100)
2. DECLARE @DynamicSQL nvarchar(250)
3. SET @ColName=’newColumn’
4. SET @DynamicSQL = ‘ALTER TABLE #Mytemp ADD [‘+ CAST(@ColName AS NVARCHAR(100)) +’] NVARCHAR(100) NULL’
5. CREATE TABLE #tmp(ID INT IDENTITY(1,1), Col1 nvarchar(100), Col2 int)

Can we select multiple columns in subquery?

If you want compare two or more columns. you must write a compound WHERE clause using logical operators Multiple-column subqueries enable you to combine duplicate WHERE conditions into a single WHERE clause.

How to dynamically choose column in SQL query?

To add more on the ‘dynamic’ side of things, use stored procedures. See here for an example: You need to use Dynamic SQL. You cannot use a variable like that in a SELECT statement. You will need to create dynamic TSQL. You don’t specify your RDBMS, but in SQL Server you would use sp_executesql (preferably) or EXEC

When to use dynamic columns in a table?

Dynamic columns allow one to store different sets of columns for each row in a table. It works by storing a set of columns in a blob and having a small set of functions to manipulate it. Dynamic columns should be used when it is not possible to use regular columns.

When to use dynamic columns and values in LINQ?

For various reasons I need to be able to allow the user to select an item from a database based on their choice of columns and values. For instance, if I have a table: The user may request a 1, 2, or more columns and the columns that they request may be different.

Do you have to have same number of columns in select statement?

Your mind starts racing. You’ll have to parse the file to read the header, see how many fields it returns, and then construct a SQL query with the same number of columns in the SELECT statement. Sounds like you’ll need some dynamic SQL.