DBGrid showing (MEMO) instead desired string.
lazarus / 16-Databases

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aamaral · 2021-09-08 01:24

I'm on this very simple piece of code but I couldn't do it work
properly. I dropped into form a LibraryLoader and set the absolute
path to .dll, a SQLite3Connection and set the absolute path to
database, a SQLQuery, a DataSource (that points to the SQLQuery) and a
DBGrid linked to that DataSource. In SQL Property of SQLQuery I have
the following statement:

Code: SQL  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i SELECT nome
AS "NOME",strftime("%d/%m/%Y", DATE(dt_apfd)) AS
"APFD",strftime("%d/%m/%Y", DATE(dt_prev)) AS "PREV",numero AS
"PROCESSO"FROM presos INNER JOIN processosON processos.idproc =
presos.idproc; 
For load results into DBGrid I'm using the code:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.Button1Click(Sender: TObject);begin  SQLite3Connection1.Open; 
DBGrid1.Columns.Clear;   SQLQuery1.Active:=True; //SQLQuery1.FieldDefs
[0].DataType:=TFieldType.ftString;  DBGrid1.Columns.Add; 
DBGrid1.Columns[0].FieldName:=SQLQuery1.FieldDefs[0].Name; 
DBGrid1.Columns.Add; 
DBGrid1.Columns[1].FieldName:=SQLQuery1.FieldDefs[1].Name; 
DBGrid1.Columns.Add; 
DBGrid1.Columns[2].FieldName:=SQLQuery1.FieldDefs[2].Name; 
DBGrid1.Columns.Add; 
DBGrid1.Columns[3].FieldName:=SQLQuery1.FieldDefs[3].Name;end; 
The Problem: when I activete SQLQuery, DBGrid is showing (MEMO) on
filds "NOME" and "PROCESSO" instead the actually string. As you can
see, I tried to
``SQLQuery1.FieldDefs[0].DataType:=TFieldType.ftString;``, but it
mades no difference.

I tried to change it via Properties, but actually, catch fields and
its properties by activating the query has a bug wich crashes Lazarus
to death, so I was trying to do it writting in program.

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GAN · 2021-09-08 02:40

QuoteThe Problem: when I activete SQLQuery, DBGrid is showing (MEMO)
on filds "NOME" and "PROCESSO" instead the actually string.
To solve this you have to enable dgDisplayMemoText in Option of the
TDBGrid in the Object Inspector.

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Zvoni · 2021-09-08 07:02

Or cast it to VARCHAR in your Select-Statement
SELECT CAST(Nome As Varchar) As Nome From...."

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aamaral · 2021-09-09 00:16

Thank you guys for such a quick reply. I tested both solution
separately. Casting my fields in Select statement worked like a charm.
Changing property dgShowMemoText in design time, it raised following
exception when while running I clicked on Button1 to populate DBGrid:
"External: SIGSEGV" - In address xxxxxxxxxx. But, changing same
property in code, it worked perfectly.

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TForm1.Button1Click(Sender: TObject);var  myDbGridOpts:
TDbGridOptions;begin  SQLite3Connection1.Open; 
DBGrid1.Columns.Clear;   myDbGridOpts:=[]; 
Include(myDbGridOpts,dgColLines); 
Include(myDbGridOpts,dgDisplayMemoText); 
Include(myDbGridOpts,dgIndicator); 
Include(myDbGridOpts,dgRowSelect);  Include(myDbGridOpts,dgTitles);  
SQLQuery1.Active:=True;   DBGrid1.Columns.Add; 
DBGrid1.Columns[0].FieldName:=SQLQuery1.FieldDefs[0].Name; 
DBGrid1.Columns.Add; 
DBGrid1.Columns[1].FieldName:=SQLQuery1.FieldDefs[1].Name; 
DBGrid1.Columns.Add; 
DBGrid1.Columns[2].FieldName:=SQLQuery1.FieldDefs[2].Name; 
DBGrid1.Columns.Add; 
DBGrid1.Columns[3].FieldName:=SQLQuery1.FieldDefs[3].Name; 
DBGrid1.Options:=myDbGridOpts;end;