SQL 查询：使用 where 子句连接两个表
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SQL query: Join two tables with where clause
提问by Mexxer
I have a problem with a SQL query. I got the following query working, which pretty basic:
我的 SQL 查询有问题。我得到了以下查询，这是非常基本的：
SELECT *
FROM table1
WHERE Date = CURDATE()
There's a column in table1 which is called h_idand a table2with the columns h_idand name
在 table1 中有一个列被调用h_id，一个table2列h_id和name
I want to join those two tables so that I have the names out of table 2 from the current date.
我想加入这两个表，以便我从当前日期获得表 2 中的名称。
I tried this, but it doesn't seem to work
我试过这个，但它似乎不起作用
SELECT t2.name, t1.field2
FROM table1 t1
INNER JOIN table2 t2 ON t1.H_ID = t2.H_ID
WHERE t1.Date = CURDATE( )
回答by aF.
It might be case sensitive.
它可能区分大小写。
or
或者
does table1 have field2 column?
table1 有 field2 列吗？
If not/so, and according to your question, try it like this:
如果不是/所以，根据你的问题，试试这样：
SELECT t2.name
FROM table1 t1
INNER JOIN table2 t2 ON t1.h_id = t2.h_id
WHERE t1.Date = CURDATE()
Another possibility is the where clause, try it like this:
另一种可能是 where 子句，试试这样：
SELECT t2.name
FROM table1 t1
INNER JOIN table2 t2 ON t1.h_id = t2.h_id
WHERE convert(varchar, t1.Date, 112) = convert(varchar, getdate(), 112)
A last possibility is that there isn't any h_id equal from table1 and table2.
最后一种可能性是 table1 和 table2 中没有任何 h_id 相等。
回答by Diego
try to remove the WHERE t1.Date = CURDATE( )and see if your record is returned.
If it is, there is a problem with your CURDATE( ), try using getdate() or try to format the date
尝试删除WHERE t1.Date = CURDATE( )并查看您的记录是否返回。如果是，则您的 存在问题，请CURDATE( )尝试使用 getdate() 或尝试格式化日期
回答by Mosty Mostacho
SQL Server does not support curdate(). That's for MySQL.
SQL Server 不支持curdate(). 那是针对 MySQL 的。
The appropriate function is getdate()
合适的函数是 getdate()
Here is a link to the official documentation
这是官方文档的链接
Edit:
编辑：
As you said in a comment, if getdate()doesn't work then you're using MySQL, then. Try this:
正如您在评论中所说，如果getdate()不起作用，那么您正在使用 MySQL，然后。尝试这个：
SELECT t2.name, t1.field2
FROM table1 t1
INNER JOIN table2 t2 ON t1.H_ID = t2.H_ID
WHERE date(t1.Date) = date(CURDATE())
回答by Mosty Mostacho
Try:
尝试：
SELECT t2.name, t1.field2
FROM table1 t1
LEFT JOIN table2 t2 ON t1.H_ID = t2.H_ID
WHERE t1.[Date] = GETDATE( )
or alternatively (MySQL):
或者（MySQL）：
SELECT t2.name, t1.field2
FROM table1 t1
LEFT JOIN table2 t2 ON t1.H_ID = t2.H_ID
WHERE t1.`Date` = CURDATE( )
