[英]get data from two tables using sql inner join, Trying to get property of non-object
[英]SQL: How to get relational data from two tables? (Using JOIN ?)
到目前为止,我一直在尝试做一些交叉关系SQL查询,但没有成功。 想知道是否有人可以提供帮助?
我有两个感兴趣的表,正在尝试找出我的哪些客户(=公司联系人1)必须处理未完成的项目。 这是表格结构:
TABLE: CUSTOMERS
ID | CUSTOMER_NAME | COMPANY_CONTACT
=================================================
1 Bob 1
2 Billy 2
3 Susan 2
4 Ryan 3
5 Sally 1
。
TABLE: TO_DOS
ID | TASK | CUSTOMER_ID
============================================
1 Make Tea 5
2 Pick flowers 1
3 Do invoices 3
4 Tidy up 4
5 Drive van 2
理想的输出是
CUSTOMER_ID | CUSTOMER_NAME | TASK
=================================================================
5 Sally Make Tea
1 Bob Pick flowers
到目前为止,我已经尝试过了,但是并没有解决任何问题:
SELECT * FROM TO_DOS
INNER JOIN CUSTOMERS
WHERE CUSTOMERS.COMPANY_CONTACT=1
任何想法,不胜感激!
SELECT CUSTOMERS.ID, CUSTOMERS.CUSTOMER_NAME, TO-DOS.TASK
FROM TO_DOS
INNER JOIN CUSTOMERS
ON TO_DOS.CUSTOMER_ID = CUSTOMERS.ID
WHERE CUSTOMERS.COMPANY_CONTACT = 1
SELECT * FROM TO_DOS AS A
INNER JOIN CUSTOMERS AS B ON A.CUSTOMER_ID=B.ID
WHERE CUSTOMERS.COMPANY_CONTACT=1
公司联系电话将确定选择哪个客户,因此,如果您想选择Sally和Bob,则将选择1。
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