Menu
I want to change the datatype of a column in a table in sql server. I used the following statement:
ALTER TABLE dbo.tbltest
ALTER COLUMN ID uniqueidentifier
But it throws the error
Operand type clash: bigint is incompatible with uniqueidentifier
955
Uniqueidentifier is a Microsoft SQL Server data type that is used to store Globally Unique Identifiers (GUIDs). It can store 16 bytes of data. The Developer tool treats the Uniqueidentifier data type as String.
Examples. The following example converts a uniqueidentifier value to a char data type. DECLARE @myid uniqueidentifier = NEWID(); SELECT CONVERT(CHAR(255), @myid) AS 'char'; The following example demonstrates the truncation of data when the value is too long for the data type being converted to.
Use the newid() function to populate the global ID or GUID column when you insert a record to the table. Note that you could use the Next_GlobalID stored procedure to get the next ID value.
Solution. Yes, there are a number of ways you can auto-generate key values for your tables. The most common ways are via the use of the IDENTITY column property or by specifying a uniqueidentifier (GUID) data type along with defaulting with either the NEWID() or NEWSEQUENTIALID() function.
You cannot convert from an integer to a uniqueidentifier. But you can do it like this.
First delete old data from the table.
Alter the column to some text-format (such as VARCHAR(200)).
ALTER TABLE dbo.tbltest
ALTER COLUMN ID VARCHAR(200)
ALTER TABLE dbo.tbltest
ALTER COLUMN ID uniqueidentifier
To be clear, you can't convert a column from numeric to uniqueidentifier directly, but you can convert numeric to varchar to uniqueidentifier.
169
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
