mysql如何计数()null字段+IFNULL
字段版本可以为空,但我也需要计算这样的行 我试着这样做:IFNULLCOUNTversion,1,但不起作用mysql如何计数()null字段+IFNULL,mysql,sql,Mysql,Sql,字段版本可以为空,但我也需要计算这样的行 我试着这样做:IFNULLCOUNTversion,1,但不起作用 select MIN(id) as id, version, IFNULL(COUNT(version), 1) as total from hlrlookup.hlrlookup WHERE create_timestamp > '2015-02-01 05:00:00' and create_timestamp < '2016-04-28 06:00:00' group
select MIN(id) as id, version, IFNULL(COUNT(version), 1) as total
from hlrlookup.hlrlookup
WHERE create_timestamp > '2015-02-01 05:00:00' and create_timestamp < '2016-04-28 06:00:00'
group by version;
help计数从不返回NULL-而是返回0。如果要计算所有行,请使用count*:
COUNT从不返回NULL-而是返回0。如果要计算所有行,请使用count*:
您在GROUPBY语句中具有版本。您可以只对每个版本的行求和:
select MIN(id) as id, version, SUM(1) as total
from hlrlookup.hlrlookup
WHERE create_timestamp > '2015-02-01 05:00:00' and create_timestamp < '2016-04-28 06:00:00'
group by version;
您在GROUPBY语句中具有版本。您可以只对每个版本的行求和:
select MIN(id) as id, version, SUM(1) as total
from hlrlookup.hlrlookup
WHERE create_timestamp > '2015-02-01 05:00:00' and create_timestamp < '2016-04-28 06:00:00'
group by version;
在我的情况下,版本可以有1…100个值和null,我认为最好先,谢谢在我的情况下,版本可以有1…100个值和null,我认为最好先,谢谢
select MIN(id) as id, version, SUM(1) as total
from hlrlookup.hlrlookup
WHERE create_timestamp > '2015-02-01 05:00:00' and create_timestamp < '2016-04-28 06:00:00'
group by version;