Hellow everyone:

I encountered an error when Postgresql in connection with Lazarus, as follows.

My environment is window xp Chinese , the installation of the Lazzrus 0.924 and Postgresql 8.3 . Lazarus can run and compile unit, the Postgresql can use pgadmin III visit. I created an data table "xiang" in the default database "postgres", including Chinese and English characters, Encoded by the uft8. and then copy the libpq.dll and other files to the Windows system directory. Next steps are:

1, Lazarus creat a new form;
2, placing a TPQconnection components to the form; 3, setting the component attributes. For example:
Hostname = localhost
DatabaseName = postgres
UserName = postgres
Password = 1234
Name = PQConnection1
Params = "select * from xiang"
4, I think should now be able to connect to database, so I put the value of the "Connected" from False to True, however, appeared error dialog:

------------------------------------------------------ error?
PQConnection1 : Connection to database failed (PostgreSQL: missing "=" after "select" in connection info string )

OK
------------------------------------------------------

I tested for a long time, including the Lazarus of 0.925 and zero 6.6.2rc, but have failed again and again, help!

Le May 28, 2008 ? 9:38 PM, Michael Van Canneyt a ?crit :

May be this text should be added somewhere in the wiki ?

Params should be empty; this is not to enter a SQL statement.

To execute a query, drop a TSQLQuery on the form (SQLQuery1, for example), and set

  SQLQuery1.SQL.Text:='select * from xiang';

and connect it to the connection component:

  SQLQuery1.Database:=PQConnection1;

Then drop a TSQLTransaction (SQLTransaction1) on the form. Connect it to the database as well:

  SQLTransaction1.Database:=PQConnection1;

and finally connect the SQLQuery1 to the transaction:

  SQLQuery1.Transaction:=SQLTransaction1;

Now set

  PQConnection1.Connected:=True;

and then

  SQLQuery1.Active:=True;

And then your query will be executed.

To use SQLDB, you need always 3 components:

1. A TSQLConnection component.
This controls the connection to the database.

2. A TSQLTransaction component.
This controls the transaction in which a query is executed. It is connected to the TSQLConnection.

3. A TSQLQuery component.
This executes queries.
It is connected to the TSQLConnection component (the database) and the TSQLTransaction (the transaction context).

Michael.

Thank you, Michael, in accordance with your recommendations, has been successfully connected! However, some new problems, form In Chinese characters appear garbled. Details are as follows:

1, Lazarus new form, from 'sqldb' tab, add the three essential components, set up a number of attributes.
2, from 'Data Access' tab, add a component: TDataSource, set attributes DataSet.
3, from the 'Data Controls' tab, add a component: TDBGrid, set attributes DataSource.

In this way, the editorial in the state of Lazarus, I can see TDBGird change from a blank into the full data. However, in the form of Chinese data garbled, even in the running after this. In an earlier time, I have tried to connect SQLite database, edit state is garbled, but in normal operation after RUN it. These two databases are UTF8 encoding, it appears to be a big problem. I am very eager to see the Chinese in the data.

UTF8 or ANSI, give me a recommendation? Thank you!

2008/5/29 Michael Van Canneyt :

Michael.

Hm.

I am not sure how to do this. I don't know how UTF-8 encoding works in Lazarus. Someone of the Lazarus team will have to answer this part of your question...

Michael.

I would say UTF-8, but I didn't tried chinese. Did you try the current lazarus from svn or daily snapshot?

http://wiki.lazarus.freepascal.org/LCL_Unicode_Support

Mattias

I will to try new snapshot version, however, whether there are other ways?

According to PostgreSQL users told me that in the P client set transcoding, for example:SET CLIENT_ENCODING TO 'GBK' .
The GBK is better able to show that the Chinese encoding, but, which position this SQL statement to add in ? I tried to add SQL attributes in TSQLQuery components, such as:

set client_encoding to 'gbk'
Select * from xiang

However, Lazarus report errors:
------------------------------
error:
Operation cannot be performed on an active dataset OK
------------------------------

If I make the database active attribute to false, then it can no longer be a True.

Op vrijdag 30-05-2008 om 04:43 uur [tijdzone +0800], schreef peng:

You should first set the client_encoding with
'TSQLConnection.ExecuteDirect('set client_encoding to ''gbk'');' Then you can open your query. (Note that you can only change the sql-statement of an query when it's closed)

Joost.

Thanks for your answer, but I do not know how to set up TSQLConnection.ExecuteDirect (......).
TSQLConnnection components in the election, I can not find ExecuteDirect attributes. Can give me concrete steps ? I am still a novice Lazarus, thank you!

Look ScreenPrint.

2008/5/30 peng :

Is not what I am doing wrong ?

2008/5/31 peng :

peng wrote

Look ScreenPrint.

Next time, please paste source code: that is easier to copy.

remvoe the line procedure TSQLConnection.ExecuteDirect ...

after the begin a line later add
  PQConnection1.ExecuteDirect('set client_encoding to ''gbk'');

Vincent

oh, I see.
Can not experiment successful, perhaps I should first learn grammar. In addition, I try - dWindowsUnicodeSupport parameters compiled Lazarus, in DBGrid component, the right to directly see that the Chinese characters. Although there are some problems, I believe it will solve.

I do not quite fluent in English, no matter what, thank you!

2008/6/1 Vincent Snijders :

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