[fpc-pascal] Connecting to a mariadb server from a Free Pascal Process using Devaun

[Terry A. Haimann]

Ok, this all works from Linux Mint running where I am running Mariadb 10.11.14.  I ahave also ran this on newer versions of mint w/o issues.  But on True Blue Debian systems I haven't gotten it to work.

Ok, yesterday I installed Devaun 6.12.86 on an old laptop (i5-2450m) and installed mariadb 11.8.6. According to the web that version is compatible with Mysql 8.0.  I created the database and table and added terry to the grant table.

I then did a fresh compile and tried running it:

fpc ImportCars.pas
Free Pascal Compiler version 3.2.2+dfsg-46 [2025/02/08] for x86_64
Copyright (c) 1993-2021 by Florian Klaempfl and others
Target OS: Linux for x86-64
Compiling ImportCars.pas
Linking ImportCars
97 lines compiled, 0.3 sec

./ImportCars 
An unhandled exception occurred at $00000000004F54E9:
EInOutError: Can not load default MySQL library ("libmysqlclient.so.21" or "libmysqlclient.so"). Check your installation.
  $00000000004F54E9
  $0000000000482FE5
  $000000000047054D

I tried then to install libmysqlclient-dev but according to apt-get that has been discontinued and replaced with either libmariadb-dev or libmariadb-dev-compat.  I tried both with the following results:

sudo apt-get install libmariadb-dev
./ImportCars
An unhandled exception occurred at $00000000004F54E9:
EInOutError: Can not load default MySQL library ("libmysqlclient.so.21" or "libmysqlclient.so"). Check your installation.
  $00000000004F54E9
  $0000000000482FE5
  $000000000047054D

I then removed that library and installed the 2nd library.

sudo apt-get remove libmariadb-dev

sudo apt-get install libmariadb-dev-compat

./ImportCars 
An unhandled exception occurred at $0000000000483045:
EInOutError: TMySQL80Connection can not work with the installed MySQL client version: Expected (8.0), got (3.4.9).
  $0000000000483045
  $000000000047054D

The source code for ImportCars.pas is 

Program ImportTow;
Uses SysUtils, StrUtils, db, sqldb, mysql80conn;

{$I /home/terry/Documents/fpc/MysqlConnLib.inc}
{$I /home/terry/Documents/fpc/DbConst.inc}

Var
	CConn:				TSqlConnector;
	CTran: 				TsqlTransaction;
	CQry:					TSqlQuery;
	IFile:				Text;
	Make, Model, Engine, Buffer,
	Trans, Drive, CityStr, 
	HwyStr, Yr:				String;
	Sql:					AnsiString;
	
Function Strip(s: String): String;
Var
	i:		LongInt;
Begin
	i := Pos(' ', s);
	s := Copy(s, i+1, Length(s));
	Strip := s;	
End;
	
	
Begin
	CConn := CreateConnection('MySQL 8.0', '127.0.0.1', 'TowDB', MyUser, MyPass);
	CreateTransaction(CConn, CTran);
	CQry := GetQuery(CConn, CTran);
	CConn.Open;
	Assign(IFile, 'cars.csv');
	Reset(IFile);
	ReadLn(IFile, Buffer);ReadLn(IFile, Buffer);
	Repeat
		Yr      := ExtractWord(16, Buffer, [',']);
		Yr      := Copy(Yr, 2, Length(Yr)-2);
		Make    := ExtractWord(14, Buffer, [',']);
		Make    := Copy(Make, 2, Length(Make)-2);
		Model   := ExtractWord(13, Buffer, [',']);
		Model   := Copy(Model, 2, Length(Model)-2);
		Model   := Strip(Model);
		Model   := Strip(Model);
		Engine  := ExtractWord(5, Buffer, [',']);
		Engine  := Copy(Engine, 2, Length(Engine)-2);
		Trans   := ExtractWord(12, Buffer, [',']);
		Trans   := Copy(Trans, 2, Length(Trans)-2);
		Drive   := ExtractWord(4, Buffer, [',']);
		Drive   := Copy(Drive, 2, Length(Drive)-2);
		CityStr := ExtractWord(9, Buffer, [',']);
		HwyStr  := ExtractWord(11, Buffer, [',']);
		
		Sql := 'Insert into CarsTable(Yr, Make, Model, Engine, Drive, Trans, City, Hwy) Values (' +
			QuotedStr(Yr) + ', ' +			
			QuotedStr(Make) + ', ' +
			QuotedStr(Model) + ', ' +
			QuotedStr(Engine) + ', ' +
			QuotedStr(Drive) + ', ' +
			QuotedStr(Trans) + ', ' +
			CityStr + ', ' +
			HwyStr + ')';
		// WriteLn('Sql:   ', Sql);
		CQry.Sql.Clear;
		CQry.Sql.Add(Sql);
		CQry.ExecSql;
		CTran.Commit;
		ReadLn(IFile, Buffer);
	Until Eof(IFile);
End.

And /home/terry/Documents/fpc/MysqlConnLib.inc contains:

function GetQuery(Conn: TSqlConnector; Tran: TSqlTransaction) : TSQLQuery;
  var MyQuery : TSQLQuery;
begin
  MyQuery := TSQLQuery.Create(Tran);
  MyQuery.Database := Conn;
  MyQuery.Transaction := Tran;
  GetQuery := MyQuery;
end;

Procedure CreateTransaction(Conn: TSqlConnector;Var Tran: TSqlTransaction);
Begin
  Tran := TSQLTransaction.Create(Tran);
  Tran.Database := Conn;
End;
	
Function CreateConnection(CType, HostAddr, Database, User, Password: String): TSqlConnector;
Var
	Conn:	TSqlConnector;
Begin
	Conn := TSQLConnector.Create(nil);
	Conn.ConnectorType 	:= CType;
	Conn.Hostname 	:= HostAddr;
	Conn.DatabaseName  	:= Database;
	Conn.UserName		:= User;
	Conn.Password		:= Password;
	CreateConnection 	:= Conn; 
End;




-- 
Terry A. Haimann <terry at haimann.us>