In SQL Server, you can create a table with a column of type SQL_VARIANT by using the CREATE TABLE statement and specifying the SQL_VARIANT type for the desired column. The SQL_VARIANT data type is a versatile type that allows you to store different types of data in a single column, including integers, floats, strings, and even other types.
Here’s an example of how to create a table with a SQL_VARIANT column:
- CREATE TABLE MyTable (
- ID INT PRIMARY KEY,
- Value SQL_VARIANT
- );
In this example:
- The MyTable table has two columns: ID and Value.
- The ID column is of type INT and serves as the primary key.
- The Value column is of type SQL_VARIANT, which means it can hold different types of data.
Inserting Data into the SQL_VARIANT Column
You can insert data of various types into the SQL_VARIANT column like this:
- INSERT INTO MyTable (ID, Value) VALUES (1, 'Hello World'); -- String
- INSERT INTO MyTable (ID, Value) VALUES (2, 123); -- Integer
- INSERT INTO MyTable (ID, Value) VALUES (3, CAST(123.45 AS FLOAT)); -- Float
- INSERT INTO MyTable (ID, Value) VALUES (4, GETDATE()); -- Date
- INSERT INTO MyTable (ID, Value) VALUES (5, NULL); -- NULL
Querying the SQL_VARIANT Column
You can query the table as you would with any other data types:
- SELECT ID, Value
- FROM MyTable;
Note on Using SQL_VARIANT
- The SQL_VARIANT type has a size limit of 8016 bytes.
- It can store data types like INT, FLOAT, BIT, DATETIME, and NVARCHAR, but it cannot store certain types like TEXT, NTEXT, IMAGE, and some others.
- Keep in mind that using SQL_VARIANT can lead to performance overhead and complexity, so it is recommended to use it only when necessary.