我为每个表分配了一个可计算可空列的赋值.简单:
SELECT table_name, count(*) FROM INFORMATION_SCHEMA.COLUMNS
WHERE is_nullable='NO'
GROUP BY table_name;
现在我必须修改它来计算"具有属性"NOT NULL""的列.以下代码是否会执行此操作或仅检查天气列名称是否为空？
CREATE TEMP TABLE A AS
SELECT DISTINCT column_name, table_name AS name FROM INFORMATION_SCHEMA.COLUMNS
WHERE column_name IS NOT NULL
GROUP BY table_name, column_name;
SELECT name, count(*) FROM A
GROUP BY name;
如果没有......有什么建议吗？