I use Firebird db and I have a table that display some fields from other tables using Join. in the software UI made with Delphi I used dblookup to change the ID and set foreign table value.
I want to display other joined fields in dblabel component once the dblookup value changed by the user. Is there an automatic way to do that without using refresh?
please advise
SQL:
select
table1.f_id,
table1.f2_id,
table1.f_name,
table2.alias_name, //<<<<<--- this is the field I want to display
from table1
left outer join table2 on (table1.f2_id = table2.f2_id)
You can use a lookup field for that. You need to create static fields for table1 first. Then add a new lookup field and wire it with appropriate values. Lookup fields are evaluated when the content of the joining fields change while a joined query has to be executed again to update the field value.
I found a good way is to read lookup fields in lookupbox and once a user select one I can read the other fields too
Related
I need to update values in a column in a specific table that exists in all our databases, but do not know the name of the column as it is user-generated.
I have two tables: one of them with user-generated columns tab_Case. In this table there is a column attachment that I need to update if the following condition applies: WHERE attachment = '0' (if true then the value needs to be changed to NULL).
In its simplest form the update query would look something like this:
UPDATE tab_Case
SET attachment = 'NULL'
WHERE attachment = '0'
This table is used in all our databases, so I need to write a query general enough to be usable across all of them.
The problem is that as the table uses user-generated columns, I have no way of knowing what the exact name is of concerned column-type, and exactly how many of those columns exist in the table.
I can, however, find out the type of the column by looking it up in another table tbl_itemPart inner joined with tbl_ValueType, like this:
SELECT ip.DbReference, ip.DbTableName, vt.ValueDescription
FROM tbl_itemPart ip
INNER JOIN tbl_ValueTypes vt ON ip.ValueTypeId = vt.ValuetypeId
WHERE vt.ValueDescription = 'file'
AND ip.DbTableName = 'tab_Case'
The columns I need are always of type 'file' and as the tab_Case table is referenced in tbl_ItemPart it is easy to find out 1) if any columns of type 'file' exist in this table, and 2) when true, what their respective names are.
So great, now I know the names of the columns that I need to potentially update. But, this is where I get lost: how do I use that information in my update query?
How do I write a script that first checks the tbl_itemPart for existence of any columns in tab_Case of type ' file', then retrieves the actual values (= names of those columns) from the DbReference column in tbl_itemPart and then finally uses those values in the update query for tab_Case?
Remember that this scripts needs to automatically do this for each of our databases, so I do not want to look up column names manually per database and then adjust my script accordingly for each of the databases.
I am very new to programming, and may be missing something very obvious, but so far I haven't been able to find a solution, or any relevant information to help me on my way.
What would be the expression to create a calculated column in Table Example 2 called "SZODMAXCALC", that would contain the SZODMAXCALC from Table Example 1 given that the data from Table Example 1 falls between the dates (DTTMSTART and DTTMEND) within Table Example 2?
Maybe this is easier done on the SQL side that loads the data?
there is no way to create a calculated column that references a column in another table.
you will need to do a join either in Spotfire (via Insert...Columns)* or on the SQL-side of things (either via a view on your database or by creating a new information link in Spotfire).
the best method depends on your data structure, implementation, and desired results, so I'm not able to recommed there. take a look at both options and evaluate which one works best.
* NOTE that Spotfire cannot join based on a Calculated Column as a common key. that is, using your example, if [WELLNAME] is a calculated column, you cannot tell Spotfire the equivalent of SELECT wellname, ... FROM table_a LEFT JOIN table_b ON table_a.wellname = table_b.wellname.
the alternative is to Insert...Transformation and choose Insert New Calculated Column, and to join on that instead.
the reason for this is that calculated columns are very mutable; they could change frequently based on a user action. it would be inefficient to re-execute the join each time the column's contents changed. conversely, a "Transformation Calculated Column" is only updated when the data table is loaded.
I have two tables, with a many to one relationship, and I am using a left join to get all the data from the many table and merge it with the data from the one table.
My first table looks like:
create table tasks (date text(6),task text(20),completed text(1))
Second table:
create table completer (data text(6),name text(20))
Keep in mind that date in the completer table is a primary key so only one name is associated with each date.
I can write a query that joins these tables and creates the correct structure:
select tasks.task,completer.name,tasks.completed from tasks left join completer on tasks.date=completer.date;
The problem with my query is my binary "completed" variable that is either 0, or 1 is always 0 after the join, no matter what value it is in the original table.
Why am I losing the data associated with the completed variable? I've tried using Access's yes/no variable instead, but that has the same problem with losing information during the join.
Thanks
I have two tables in my database, one is Transactions and the other is TransactionHistories. The latter is essentially an auditing table, whereby a trigger executes on insert, update and delete on Transactions to capture a screenshot of the data.
I am successfully retrieving all of the data stored in the Transactions table where the columns match, but the difficulty comes where I am trying to retrieve data from another table using a foreign key. For instance:
The transaction table has a field "TransactionType_TransactionTypeId", but in the audit table we wish to store its 'name' equivalent as "TransactionTypeName". This needs to be populated from the "TransactionTypes" table, which has the fields "TransactionTypeId" and "Name".
I am struggling to write a query to retrieve this as we wish. I am trying something similar to the following but having little success:
SELECT #TransactionTypeName=Name
FROM TransactionTypes
WHERE inserted.TransactionType_TransactionTypeId=TransactionTypes.TransactionTypeId;
I'm assuming that is a syntactic nightmare. If someone could point me in the right direction I would be extremely grateful!
well to get a name you should do the following
select #TransactionTypeName = TT.Name
from inserted as i
left outer join TransactionTypes as TT on TT.TransactionTypeId = i.TransactionType_TransactionTypeId
but you have to know that inserted table can have more than one row, and you are getting value for only one row.
I want to get the results of a left join between two tables, with both having a column of the same name, the column on which I join. The following query is seen as valid by the import/export wizard in SQL Server, but it always gives an error. I have some more conditions, so the size wouldn't be too much. We're using SQL Server 2000 iirc and since we're using an externally developed program to interact with the database (except for some information we can't retrieve that way), we can not simply change the column name.
SELECT table1.*, table2.*
FROM table1
LEFT JOIN table2 ON table1.samename = table2.samename
At least, I think the column name is the problem, or am I doing something else wrong?
Do more columns than just your join key have the same name? If only your join key has the same name then simply select one of them since the values will be equivalent except for the non-matching rows (which will be NULL). You will have to enumerate all your other columns from one of the tables though.
SELECT table2.samename,table1.othercolumns,table2.*
FROM table1
LEFT JOIN table2 ON table1.samename = table2.samename
You may need to explicitly list the columns from one of the tables (the one with less fields), and leave out the 2nd instance of what would be the duplicate field..
select Table1.*, {skip the field Table2.sameName} Table2.fld2, Table2.Fld3, Table2.Fld4... from
Since its a common column, it APPEARS its trying to create twice in the result set, thus choking your process.
Since you should never use select *, simply replace it with the column names of the columns you want. THe join column has the same value (or null) in both sides of the join, so only select one of themm the one from table1 which will always have the value.
If you want to select all the columns from both tables just use Select * instead of including the tables separately. That will however leave you with duplicate column names in the result set, so even reading them out by name will not work and reading them by index will give inconsistent results, as changing the columns in the database will change the resultset, breaking any code depending on the ordinals of the columns.
Unfortunately the best solution is to specify exactly the columns you need and create aliases for the duplicates so they are unique.
I quickly get the column headings by setting the query to text mode and copying the top row ...