MYSQL Frustration
lazarus / 16-Databases

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nicod98 · 2015-09-19 12:26

A long time ago I used to program in Delphi (1/2/3) but after more
than a decade of something else I decided return to Pascal for some
private projects, and found Lazarus.

I manage to make quite a nice application, but somehow I NEVER seem to
be able to update the MySQL Backend database.
dbGrids are working fine, but changes are never written to the
database.

After more than a hundred hours of searching and trying (and reading
the wiki over and over...), I am convinced that something is wrong
with how I use the "transaction" part of it.
Every "solution" to the mysql-problem I found is doing everything in
code, which defeats the purpose of the IDE in my eyes, and therefore
is NOT an option.

Is there anyone around here that can give a simple step by step, of a
single form application with 1 table with mysql and 1 dbGrid that
really works???

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rvk · 2015-09-19 12:51

Quote from: nicod98 on September 19, 2015, 02:26:08 pmAfter more than
a hundred hours of searching and trying (and reading the wiki over and
over...), I am convinced that something is wrong with how I use the
"transaction" part of it. Every "solution" to the mysql-problem I
found is doing everything in code, which defeats the purpose of the
IDE in my eyes, and therefore is NOT an option.
You always need to do "some" coding in events. Even in Delphi.

If you show us some code of what you have under your "Save definite
data to database"-button we can see why it's not saving for you.

I take it (if you already went through the wiki) you have something
like this:
Code: [Select]procedure
TForm1.ApplyAllDataToDatabaseButton1Click(Sender: TObject);
begin
  SQLQuery1.ApplyUpdates;
  SQLTransaction1.Commit; // or CommitRetaining depending on your
needs
end;
(You could also do this in a OnClose-event.)

Without seeing what you do to actually apply the data to the database,
we can't help you much.

(Note: ApplyUpdates is something you need to do manually in code in
Lazarus/FPC. Delphi does this automatically for you but FPC does not.)

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marcov · 2015-09-19 13:19

It would be more correct to say sqldb does. Afaik ZEOS under FPC
doesn't require it either.

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mse · 2015-09-19 14:38

AFAIK SqlDB now supports it too.
Wit MSEgui it is also possible to make simple SQL applications without
code, an example is here:
https://gitlab.com/mseuniverse/mseuniverse/tree/master/samples/db/simp
lemysql
From README.TXT:
Code: [Select]How to make a simple MySQL MSEgui application without
code:

Place a tmysqlconnection component from tab DB on the form, name it
"conn".
Place a tmsesqltransaction component from tab DB on the form, name it
"trans".
In "conn.transaction" select "trans".
Place a tmsesqlquery component from tab DB on the form, name it
"query".
In "query.database" select "conn".
In "query.SQL" enter "select * from table1".
In "conn" enter the values for "DatabaseName", "HostName", "UserName"
and
 "Password".
If the database is utf-8 encoded set
"conn.controller.options.dbo_utf8"
 to "true".
Place a tmsedatasource component from tab DB on the form, name it
"dataso".
In "dataso.dataset" select "query".
Place a tdbnavigator component from tab DB on the form, name it
"dbnav".
In "dbnav.datasource" select dataso.
Place a tdbstringgrid component from tab DB on the form, name it
"grid".
In "grid.datalink.datasource" select "dataso".
Set "grid.options.dsgo_autofields to "true".
Set "query.active" to "true".

The database should contain a table "table1" with an autoinc primary
key field.

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miab3 · 2015-09-19 14:46

@ nicod98

In ZEOS default is autocommit.
Here, well-functioning version 7.2 svn 3642:
http://svn.code.sf.net/p/zeoslib/code-0/branches/testing-7.2/
In addition ZEOS works identically in Delphi(7-XE10) and Lazarus.

Michal

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LacaK · 2015-09-20 17:10

Quote from: mse on September 19, 2015, 04:38:59 pmAFAIK SqlDB now
supports it too.
Yes incomming FPC 3.0 has introduced:
TSQLQuery.Options property, where you can set: sqoAutoApplyUpdates
and/or sqoAutoCommit and sqlDB will do work for you.