Discussion of article "SQLite: Native handling of SQL databases in MQL5" - page 10

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Renat Fatkhullin #:
Thanks, we'll check it out.

Likewise!

You should also check ON DELETE and ON UPDATE:

  • NO ACTION
  • SET NULL
  • SET DEFAULT
  • RESTRICT
  • CASCADE

Without this, the work becomes very complicated.

 
Anatoli Kazharski #:

Thanks for the reply!

For some reason I'm not getting the result I expect:

//---

Where is the error?

And this is something I'd like to deal with as well:

Our mistake was building without SQLITE_DEFAULT_FOREIGN_KEYS.

Already fixed and working - will be available in beta tonight. The table with FOREIGN KEYS will need to be recreated for the example above.

We will look at the commands in the panel later.

 
Renat Fatkhullin #:

Our mistake was to build without SQLITE_DEFAULT_FOREIGN_KEYS.

It's already fixed and working - will be available in beta tonight. The table with FOREIGN KEYS will need to be recreated for the example above.

We will look at the commands in the panel later.

Thank you! I will definitely test it.

 
Hotkey F9 - execute request does not work. You can see the expectation of the stated can be seen if you put the cursor on the "Execute" button. But, neither when pressing F9 with the cursor in the command line, nor when moving the cursor (mouse pointer) to other (other) positions, the declared F9 does not work. Using the mouse to press "Run" is not attractive.
 

Hi,

Something doesn't seem right though.
I created a "signals.sqlite" database and got confirmation that it exists. I saved the data to the database and got confirmation that 63 records were saved. Unfortunately, I am unable to read anything from the database and when I check the database, I cannot find the "signals.sqlite" file. However, i find the directory  in XM MT5/Bases/signals and in this directory the file "signals.dat", which is unreadable for me and has a size of 3845 kb.
The question is where can I find the "signals.sqlite" file and if not, how can I edit it?

I use XM MT5 build 3521

 
Zbigniew Mirowski #: Something doesn't seem right though. I created a "signals.sqlite" database and got confirmation that it exists. I saved the data to the database and got confirmation that 63 records were saved. Unfortunately, I am unable to read anything from the database and when I check the database, I cannot find the "signals.sqlite" file. However, i find the directory  in XM MT5/Bases/signals and in this directory the file "signals.dat", which is unreadable for me and has a size of 3845 kb. The question is where can I find the "signals.sqlite" file and if not, how can I edit it? I use XM MT5 build 3521

The file is usually stored in "<data folder>\MQL5\Files" unless you used the DATABASE_OPEN_COMMON flag.

The "signals.dat" has nothing to with SQLite.

 
Fernando Carreiro #:

The file is usually stored in "<data folder>\MQL5\Files" unless you used the DATABASE_OPEN_COMMON flag.

The "signals.dat" has nothing to with SQLite.

Hi, Fernando, thanks for answer

I expected it, because it is in the description, but unfortunately the files directory is empty and I created the database with this command:

filename="signals.sqlite"

int db=DatabaseOpen(filename, DATABASE_OPEN_READWRITE | DATABASE_OPEN_CREATE |DATABASE_OPEN_COMMON);

e.g. with DATABASE_OPEN_COMMON flag


DATABASE_OPEN_COMMON

The file is in the common folder of all terminals


how to interpret ii?
 

@Zbigniew Mirowski #: I expected it, because it is in the description, but unfortunately the files directory is empty and I created the database with this command:

filename="signals.sqlite"

int db=DatabaseOpen(filename, DATABASE_OPEN_READWRITE | DATABASE_OPEN_CREATE |DATABASE_OPEN_COMMON);

e.g. with DATABASE_OPEN_COMMON flag

DATABASE_OPEN_COMMON

The file is in the common folder of all terminals

how to interpret ii?

Then you will find it in "%APPDATA%\MetaQuotes\Terminal\Common\Files".
 
Fernando Carreiro #:
Then you will find it in "%APPDATA%\MetaQuotes\Terminal\Common\Files".

Well, now I have a new problem. I came to the conclusion that maybe the error lies in the fact that I installed this MT5 on the C drive in Program files and maybe there are some access restrictions in the new Win11. So I installed a new instance on another disk, new demo account and tried to install this database there and... I got:
2022.11.30 10:37:26.036 CreateDB (EURUSD,H1) database error, table Signals already exists.
When creating a database, I immediately create tables. Create does not throw an error, because it is also opening the database, but creating a table throws an error.
I searched the whole computer and the "signals.sqlite" files were not found, but I found the "signals.dat" file again

Wow, I found the file "signals.sqlite"

C:\Users\name\AppData\Roaming\MetaQuotes\Terminal\Common\Files

there is only structure in the "signals.sqlite" file and I suspect there is data in the signals.dat file

C:\Users\name\AppData\Roaming\MetaQuotes\Terminal\Common\Files

 
Zbigniew Mirowski #: Wow, I found the file "signals.sqlite" C:\Users\name\AppData\Roaming\MetaQuotes\Terminal\Common\Files

But is that not exactly where I told you where you would find it?

Then you will find it in "%APPDATA%\MetaQuotes\Terminal\Common\Files".

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