以下所有结果彼此无关,我们不能使用任何条件。
ID ---------- 1 2 3 4 5 6 7选择了7行。
NAME ----------------- SRUJAN DEERAJ VINEETH CHANIKYA LAVANYA KAVITHA BUNNY选择了7行。
AGE ---------- 23 24 26 25 29 28 24选择了7行。
ADDRESS ------------- NAGARAM BANDLAGUDA UPPAL KUKATPALLY HB COLONY MOULALI BOUDHA NAGAR选择了7行。
SALARY ---------- 12000 13000 14000 15000 16000 17000 18000选择了7行。
我用了
SQL>select id,name,age,address,salary from table1,table2,table3,table4,table5;但它显示选择了16807行
我想只得到一张桌子。 请建议一个查询。
all the below results are not related to each other wheras we cannot use any condition.
ID ---------- 1 2 3 4 5 6 77 rows selected.
NAME ----------------- SRUJAN DEERAJ VINEETH CHANIKYA LAVANYA KAVITHA BUNNY7 rows selected.
AGE ---------- 23 24 26 25 29 28 247 rows selected.
ADDRESS ------------- NAGARAM BANDLAGUDA UPPAL KUKATPALLY HB COLONY MOULALI BOUDHA NAGAR7 rows selected.
SALARY ---------- 12000 13000 14000 15000 16000 17000 180007 rows selected.
I USED
SQL>select id,name,age,address,salary from table1,table2,table3,table4,table5;but it showing 16807 rows selected
i want to get only one table. please suggest a query.
最满意答案
2个表只有1列且两者都没有关系的唯一可能的连接是交叉连接。 你无法避免它。 当你试图加入时,你会得到同样的结果。 最好的方法是将序列创建为ID,然后在table2的select语句中调用它。
CREATE SEQUENCE TEST_SEQ START WITH 1 MAXVALUE 9999999999999999999999999999 MINVALUE 1 NOCYCLE; select TEST_SEQ.nextval ID,col1 NAME from table2;The only possible join between 2 tables having only 1 columns and both having no relation is cross join. You cannot avoid it. And the same you are getting when you tried to join. The best way for you is to create a sequence as ID and then call it in your select statement of table2.
CREATE SEQUENCE TEST_SEQ START WITH 1 MAXVALUE 9999999999999999999999999999 MINVALUE 1 NOCYCLE; select TEST_SEQ.nextval ID,col1 NAME from table2;更多推荐
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