如何获取sql中给定行中具有空值的列的计数？

SELECT COUNT(*) 
FROM (
    SELECT 
        CASE 
            WHEN column1 IS NULL THEN 1 
            ELSE 0 
        END +
        CASE 
            WHEN column2 IS NULL THEN 1 
            ELSE 0 
        END +
        CASE 
            WHEN column3 IS NULL THEN 1 
            ELSE 0 
        END +
        ...
        CASE 
            WHEN columnN IS NULL THEN 1 
            ELSE 0 
        END AS count_null_columns
    FROM table_name
    WHERE condition
) AS result;

DECLARE @sql NVARCHAR(MAX);
SET @sql = N'SELECT ';
SELECT @sql = @sql + N'CASE WHEN ' + COLUMN_NAME + N' IS NULL THEN 1 ELSE 0 END + '
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'table_name' AND TABLE_SCHEMA = 'schema_name';
SET @sql = LEFT(@sql, LEN(@sql) - 2) + N' AS count_null_columns FROM table_name WHERE condition';
EXEC sp_executesql @sql;