How can I add an identity column to a table in Snowflake?
If you want to ADD an IDENTIFY COLUMN in a Snowflake table, you just need to either:\n\n1. CREATE the TABLE with the IDENTITY VALUE LIKE THIS:\n\nCREATE OR REPLACE TABLE EXAMPLE_TABLE(\n YOUR_ID IDENTITY START 1 INCREMENT 1, \n YOUR_NAME VARCHAR\n);\n*Note: you can replace IDENTITY with AUTOINCREMENT – it works exactly the same way.\n\n2. ALTER a TABLE and add the IDENTIFY VALUE COLUMN [REMEMBER – you can only do this if there is NO DATA within the TABLE!]\n\nALTER TABLE EXAMPLE_TABLE ADD COLUMN YOUR_ID INT IDENTITY(1,1);\n\n*Note: All of my examples show IDENTITY(1,1) where we start from the number 1 and increment by 1 for each row. You can use different values here if you want. You can start from any number and you can increment any amount as well. IF you do not specify a START VALUE or an INCREMENT VALUE then the default values for both of them are equal to 1.\n\nYou also have 1 additional method to add auto-numbering. This is by using the SEQUENCE object. This object is separate from the table itself so its great for if you want a unique value ACROSS multiple tables. The syntax to CREATE a SEQUENCE is below. Again, a sequence is a separate object from the table itself but its very similar to an IDENTITY or AUTOINCREMENT functionality but its more versatile I would say.\n\nCREATE SEQUENCE EXAMPLE_SEQUENCE_FOR_YOU START 1 INCREMENT 1;\n// this creates a sequence the same as before with a START VALUE of 1 and an INCREMENT VALUE of 1.\n\nCREATE OR REPLACE TABLE EXAMPLE_TABLE(\n YOUR_AUTO_ID SET DEFAULT EXAMPLE_SEQUENCE_FOR_YOU.nextvalue;\n YOUR_NAME VARCHAR\n);\n//or\nALTER TABLE ALTER COLUMN YOUR_AUTO_ID SET DEFAULT EXAMPLE_SEQUENCE_FOR_YOU.nextvalue;\n\nFYI: The AUTOINCREMENT AND IDENTITY actually use sequences behind the scenes!\n