I have a mySQL DB in which two columns may refer to the same Identifier. One column is PartyA and the other is PartyB (as in counter-parties to an exchange, or nodes in a graph).
我有一个mySQL数据库,其中两列可能引用相同的标识符。一列是PartyA,另一列是PartyB(如交换的对方或图中的节点)。
Curious if there is an easy mySQL query to find the unique count of Party Identifies?
好奇如果有一个简单的mySQL查询来查找Party Identifies的唯一计数?
Currently I pull PartyA, then PartyB, row-bind the two, then count distinct.
目前我拉PartyA,然后PartyB,行绑定两个,然后计数不同。
E.g.:
Clearly the distinct count of PartyA and PartyB is 9, even through neither PartyA nor PartyB have a distinct count of 9.
很明显,PartyA和PartyB的独特统计数字是9,即使PartyA和PartyB都没有明显的9。
1 个解决方案
#1
SELECT COUNT(1)
FROM (
SELECT PartyA FROM theTable
UNION
SELECT PartyB FROM theTable
) AS pQ;
#1
SELECT COUNT(1)
FROM (
SELECT PartyA FROM theTable
UNION
SELECT PartyB FROM theTable
) AS pQ;