Php 在同一查询中选择*并在mysql中求和
我需要创建一个选择所有表列和新列“sum”的查询, 大概是这样的:Php 在同一查询中选择*并在mysql中求和,php,mysql,sql,Php,Mysql,Sql,我需要创建一个选择所有表列和新列“sum”的查询, 大概是这样的: SELECT *, sum(amount) as `items_total` FROM mytable WHERE ... 有什么想法吗???按照下面的方法尝试- SELECT col1, sum(amount) as items_total FROM mytable WHERE mycol = <condition> GROUP BY col1;
SELECT *,
sum(amount) as `items_total`
FROM mytable
WHERE ...
有什么想法吗???按照下面的方法尝试-
SELECT col1,
sum(amount) as items_total
FROM mytable
WHERE mycol = <condition>
GROUP BY col1;
选择col1,
项目合计金额
从mytable
其中mycol=
col1分组;
您可以使用子选择来计算总和:
select t.*, (select sum(amount) FROM mytable) as `items_total`
from mytable t
将a、b、c和d视为表中的列名,colsum是该特定列的总和 我认为这应该行得通
select colname ,colsum from (select 'a' colname , sum(a) colsum from tablename union all select 'b' colname ,sum(b) colsum from tablename union all
select 'c' colname , sum(c) from tablename union all select 'd' colname , sum(d) colsum from tablename ) tablename where (condition) order by colsum asc;
如果只需要表中所有列的列名,请使用
SELECT `COLUMN_NAME` FROM `INFORMATION_SCHEMA`.`COLUMNS` WHERE `TABLE_SCHEMA`='database_name' AND `TABLE_NAME`='table_name'
您将要根据某个内容对
分组。Item\u total是表中所有行的总和,或者……您好,col1是什么?我需要我所有的列,我有30多行。这不会对所有行求和,至少我认为这是我需要的。谢谢,这正是我想要的needed@pey22你能把答案标为正确吗?谢谢
SELECT `COLUMN_NAME` FROM `INFORMATION_SCHEMA`.`COLUMNS` WHERE `TABLE_SCHEMA`='database_name' AND `TABLE_NAME`='table_name'