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"Select .. From.." in TQuery for many database files...

Hi, Experts!
I'm making special SQL builder for 3 database files of IB Database. I want to know how to write down "Select ... From" command for 3 database IB files without use Aliases.
I use 3 TDataBase components for access IB DataBase files.
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DValery
Asked:
DValery
1 Solution
 
FreeLoginCommented:
hello DValery.
What do you mean by "Without using Aliases" ?

What is sure, is that you can solve your problem like this :

Select ......
from :Alias1:Table1,:Alias2:Table2,:Alias3:Table3
where ....

where :Alias1: is the name of the first alias inserted between ::


regards
                FreeLogin
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kretzschmarCommented:
Hi  DValery,

the Database-property of your Query should have the Alias which shows to your Interbase Database

The Sql-Statement couls be shown as follows

Select a.field, b.field, c.field,... from TableA , TableB b, TableC c where a.Field = b.Field and b.Field=c.Field order by a.field

the word field should contain your fieldnames, by the where-clause the typs of fields should be the same, in order clause you select the sortorder.

meikl
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EmmDiehCommented:
Look in the help under "Heterogenous queries"
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DValeryAuthor Commented:
Thanks EmmDieh, for old true: "...read the documentation".
The Help say me:
..
As an alternative to using a BDE alias to specify the database in a heterogeneous query, you can use a TDatabase component. Configure the TDatabase as normal to point to the database, set the TDatabase.DatabaseName to an arbitrary but unique value, and then use that value in the SQL statement instead of a BDE alias name.
..
It is I looking for...
EmmDieh, you can to get 50 points...
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EmmDiehCommented:
Thanks,
but keep in mind that as far as I know result sets from
multiple databases in heterogenous queries are joined
on the client side which may result in a really low
performance, because a the rows have to be transmitted
over the network.
You can check this with SQL-Monitor.
Consider using one database instead.

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