我尝试加入两个表，但另一个表名在第一个表的列中。 是否可以加入或是否有

Question

Joining two tables...one table name is also the column name. SQL

FROM table fs
INNER JOIN fs.tablenamecolumn st 
ON fs.t_ID=st.t_ID
where t=1250```

error--
Invalid object name 'fs.tablenamecolumn '.

Answer 1

Edit: I just realised this is for MySQL, Not MSSQL. SO you will need to use a prepare statement. hopefully you can use the below as a guide to help you.

You will need to create the SQL dynamically eg

DECLARE @tablename AS VARCHAR(100)
SELECT  @tablename = tablnamecolumn FROM [yourtable]

DECLARE @query AS NVARCHAR(MAX)
SET     @query = 
'SELECT * 
 FROM [yourtable] 
 INNER JOIN ' + @tablename + ' 
 ON fs.t_ID=st.t_ID
 WHERE t=1250'

EXEC sp_executesql @query

Answer 2

On where condition give table alias name on column the alias name will be on which table you want filtering.

select FROM table fs
INNER JOIN fs.tablenamecolumn st 
ON fs.t_ID=st.t_ID
where fs.t=1250

Answer 3

Not really. This is even quite hard using dynamic SQL because the name might change from row to row.

You should revisit your data model. What you are doing is probably quite unnecessary.

If there is a finite set of tables, you can use left join :

FROM table fs LEFT JOIN
     table1 t1
     ON fs.t_ID = t1.t_ID AND
        fs.tablenamecolumn = 'table1' LEFT JOIN
     table2 t2
     ON fs.t_ID = t2.t_ID AND
        fs.tablenamecolumn = 'table2' LEFT JOIN
     . . .
WHERE fs.t = 1250