Generate scripts to change all columns in MSSQL table to allow NULL

change_columns_allow_null.sql

DECLARE
@schema SYSNAME = '',
@table SYSNAME = ''

-- Declare variables to store column name and data type
DECLARE @column_name varchar(50)
DECLARE @data_type varchar(50)

-- Declare a cursor to loop through the columns of the table
DECLARE column_cursor CURSOR FOR
    SELECT c.name, ty.name
    FROM sys.columns c
    JOIN sys.types ty ON c.user_type_id = ty.user_type_id
    INNER JOIN sys.tables t ON c.object_id = t.object_id
    INNER JOIN sys.schemas s ON t.schema_id = s.schema_id
    WHERE s.name = @schema AND t.name = @table
    AND c.is_nullable = 0 -- Only select columns that are not null

-- Open the cursor and fetch the first row
OPEN column_cursor
FETCH NEXT FROM column_cursor INTO @column_name, @data_type

-- Loop through the rows until there are no more
WHILE @@FETCH_STATUS = 0
BEGIN
    -- Print a script to alter the column to allow nulls
    PRINT 'ALTER TABLE ' + QUOTENAME(@schema) + '.' + QUOTENAME(@table) + ' ALTER COLUMN ' + QUOTENAME(@column_name) + ' ' + @data_type + ' NULL'

    -- Fetch the next row
    FETCH NEXT FROM column_cursor INTO @column_name, @data_type
END

-- Close and deallocate the cursor
CLOSE column_cursor
DEALLOCATE column_cursor