Question

Let’s say I have this table:

name        varchar(255),
quantity    integer,
value       float

When I used this code:

select left(name, 99), quantity, value from table;

But I’ve got all the 255 spaces (by space I mean width length, not the real space chars) on the first column of the dbgrid and the other two fields where away unless I used the scroll bar and my objective was to make scroll bars not necessary.

How do I get this goal correctly? I use Firebird and MySQL.

I can not do this by pascal code nor define it on the Fields object of the table component because this codes comes from many tables as this is a report generator and the first field is not always the same and for each report I have to use a different SQL code.

PLEASE, EVERYBODY READ THE ALL QUESTION BEFORE ANSWERING. THE FIRST 3 ANSWER WHERE WRONG BECAUSE THEY DID NOT CONSIDERED WHAT AS WRITTEN IN THE LAST PARAGRAPH!

Answer 1

Since you’ve said you can’t do it on the TField level or in your Delphi code, you can use Trim() or Left(), depending on the database you’re using, on the column to remove the blank spaces you don’t want to display:

For instance, in many SQL dialects you could use something like:

SELECT Col1, Col2, Trim(Col3) as Col3 FROM yourtable 
WHERE somecondition

Some allow this instead:

SELECT Col1, Col2, Left(Col3, MaxCharWidthAllowed) as Col3 FROM yourtable 
WHERE somecondition

or

SELECT Col1, Col2, Substring(Col3, 1, MaxCharWidth) as Col3 FROM yourtable

As a quick test (I don’t have FB, but have SQL Server 2008, so I used it), I created the following test data in SQL Server Management Studio:

I then created a new D2007 VCL Forms application, and performed the following steps:

• Dropped an TADOConnection on the form (ADOConnection1), and set up the connection string to the test data above
• Dropped two TADOQuery components on the form (ADOQuery1 and ADOQuery2), and set their Connection properties to ADOConnection1
• Dropped two TDataSource components on the form (DataSource1 and DataSource2) and connected their DataSet properties to the matching ADOQuery1 and ADOQuery2
• Dropped two TDBGrid components (DBGrid1 and DBGrid2) and set their DataSource properties to the matching DataSource1 and DataSource2.
• Added SELECT * FROM test to the SQL for ADOQuery1
• Added SELECT Substring(itemname, 1, 30) as itemname, quantity, value FROM test as the SQL of ADOQuery2. The length of 30 was arbitrarily chosen as being a small enough value to demonstrate the considerably smaller column width.
• Set ADOConnection1.Connected to True, and set both TADOQuery.Active properties to True.

The above produced this output (at design time, without ever compiling or running the application), with the top grid being DBGrid1:

As you can see, in DBGrid2, which is connected to ADOQuery2 with the Substring in the SQL, the first column is correctly sized to 30 characters width.