Question

我有一张表格，其中包含存储在其中的na app的一些“规则”

id,pi1,pi2,pi3
"1","1",,
"2","2",,
"3","3",,
"4","4",,
"5","5",,
"6","6",,
"7","7",,
"8","8",,
"9","9",,
"10","10",,
"11","11",,
"12","12",,
"13","13",,
"14","14",,
"15","15",,
"16","16",,
"17","17",,
"18","18",,
"19","19",,
"20","1","13",
"21","1","18",
"22","2","3",
"23","2","4",
"24","2","6",
"25","2","7",
"26","2","7","16"
"27","2","7","19"
"28","2","16",
"29","2","17",
"30","2","18",
"31","2","19",
"32","3","10",
"33","3","12",
"34","3","16",
"35","4","16",
"36","4","19",
"37","5","18",
"38","6","11",
"39","6","13",
"40","6","18",
"41","6","19",
"42","7","16",
"43","7","18",
"44","7","19",
"45","8","13",
"46","8","18",
"47","9","11",
"48","9","16",
"49","9","18",
"50","9","19",
"51","10","12",
"52","10","16",
"53","11","13",
"54","11","18",
"55","12","18",
"56","13","16",
"57","13","18",
"58","16","18",
"59","17","18",
"60","18","19",
"61","4","18",

而另一个是在移动中生成的，具有来自定义的一组数字的所有可能组合（例如，我选择了这个，2,7,16,17,18,19），这就是输出

idPI,pi1,pi2,pi3
"1","2",,
"2","7",,
"3","16",,
"4","17",,
"5","18",,
"6","19",,
"7","2","7",
"8","2","16",
"9","2","17",
"10","2","18",
"11","2","19",
"12","7","16",
"13","7","17",
"14","7","18",
"15","7","19",
"16","16","17",
"17","16","18",
"18","16","19",
"19","17","18",
"20","17","19",
"21","18","19",
"22","2","7","16"
"23","2","7","17"
"24","2","7","18"
"25","2","7","19"
"26","2","16","17"
"27","2","16","18"
"28","2","16","19"
"29","2","17","18"
"30","2","17","19"
"31","2","18","19"
"32","7","16","17"
"33","7","16","18"
"34","7","16","19"
"35","7","17","18"
"36","7","17","19"
"37","7","18","19"
"38","16","17","18"
"39","16","17","19"
"40","16","18","19"
"41","17","18","19"

我想只使用pi1，pi2，pi3列连接两个表。我进入了这个

SELECT DISTINCT table1.pi1, table1.pi2, table1.pi3, 
FROM db.table1
inner JOIN db.table2 c1
ON db.table1.pi1 = c1.pi1

具有以下结果

pi1,pi2,pi3,
2,,,
7,,,
16,,,
17,,,
18,,,
19,,,
2,3,, //this wrong shouldn't be here
2,4,, //this wrong shouldn't be here
2,6,, //this wrong shouldn't be here
2,7,,
2,7,16,
2,7,19,
2,16,,
2,17,,
2,18,,
2,19,,
7,16,,
7,18,,
7,19,,
16,18,,
17,18,,
18,19,,

我做错了什么？

Answer 1

如果你想使用pi1，pi2，pi3列作为键来连接这两个表，那么你需要在INNER JOIN ... ON语句中指定，如下所示：

SELECT t1.pi1, t1.pi2, t1.pi3
FROM table1 AS t1 
INNER JOIN table2 AS t2
ON t1.pi1 = t2.pi AND t1.pi2 = t2.pi2 AND t1.pi3 = t2.pi3;

一个简单的连接是不够的，但另一个不输出我想要的

1 个答案: