在Delphi应用程序中使用哪个嵌入式数据库？

Question

I am creating a desktop app in Delphi and plan to use an embedded database. I've started the project using SQlite3 with the DISQLite3 library. It works but documentation seems a bit light. I recently found Firebird (yes I've been out of Windows for a while) and it seems to have some compelling features and support.

What are some pros and cons of each embedded db? Size is important as well as support and resources. What have you used and why?

Answer 1

I'm using Firebird 2.1 Embedded and I'm quite happy with it.I like the fact that the database size is practically unlimited (tested with > 4 GB databases and it works) and that the database file is compatible with the Firebird Server so I can use standard tools for database management and inspection. Distribution consists of dropping few files in your exe folder.

Simultaneous access from multiple programs is not supported but simultaneous access from multiple threads is (as long as you ensure that only one 'connect' operation is in progress at any given moment).

Answer 2

I have used SQlite3 for a lot of projects (but from C/C++ and Objective-C). It's extremely small -- no dependencies whatsoever -- database is in a single file.

It's the db of choice for Mac developers because it's directly supported by CoreData and on the iPhone -- so there is a big user base (not to mention all of the other users).

Answer 3

I've been using SQLite (via DISQLite3) in FeedDemon for several months, and I highly recommend it - it has been extremely fast and stable. As Javier said, the docs for the library may be thin, but the docs for SQLite itself are very good.

Answer 4

I've used DBISAM on a number of projects. It is completely embedded without even a need for an external DLL. Unlike the others you listed it is commercial. A lot of great features though and very well documented and supported. The have a successor to it that I haven't tried yet though.

Answer 5

Let's see, quick comparison:

SQLite:

• dynamic typing in the database
• cross-platform files
• runs on Windows, Linux, Mac, etc.
• public domain
• supports transactions
• relies on file system security, does not include own security

Firebird embedded:

• strong typing in the database
  • not all SQL datatypes are supported
• cross-platform files
  • Firebird embedded only runs on Windows
  • Files from Firebird embedded are in the same format as the full server version
  • Files from Firebird embedded can be copied to a non-Windows server for use
• available under a modified MPL ("what's ours is ours and must remain free, what's yours is yours and you don't have to release it")
• supports transactions, triggers, etc.

MySQL embedded:

• support for SQL features depends on file format
• (IIRC) cross-platform files
• GPL unless you pay royalties
• runs on Windows, Linux, Mac
• incredibly popular with the open source crowd

Even embedded databases have their strengths and weaknesses. You'll need to weigh those strengths and weaknesses against what you're doing to decide.

Answer 6

Firebird embedded is our #1 choice because with no code changes, a single user Delphi app with embedded database can be migrated to a multi-user server based deployment without sacrificing any of the high end features (such as stored procedures, triggers, views, etc.). And its a TRUE free database and doesn't GPL your code in the process.

Answer 7

Strongly recommend to use AnyDAC when working with Databases and Delphi - then you can choose to target FB or SQLite seamlessingly.

My preference would be for FB for embedded apps. Tom

Answer 8

I use Sybase's Advantage Database Server, but I'm also the R&D Manager, so this post is biased. :)

We have native Delphi TTable and TQuery components for both WIN32 VCL and VCL.NET. Direct table access in addition to SQL support makes Advantage unique among many of the other Delphi offerings. Advantage supports large tables (only limited by the number of records, 2 billion) and has a free local engine, which is nice for development PCs and for small customer sites that don't require client/server functionality. Switch to client/server with a single connection property, no other changes.

We have a ton of clients so accessing the data outside of Delphi is also very easy (.NET data provider, ODBC, OLE DB, PHP, Perl, JDBC, etc).

Main Product Web Site: http://www.advantagedatabase.com Developer's Web Site: http://devzone.advantagedatabase.com

Answer 9

It really depends what you need. For single-user applications, Firebird Embedded or SQLite are probably best choices (and price is right). On the other end, if you need support for large number of multiple users, you should probably use regular Firebird instead of Embedded version (server is simple to install so you won't have much problems here).

And if you need something in between, for a moderate multi-user application, one of flat databases would be better. I found that ComponentAce's Absolute Database better choice for my needs than DBISAM, NexusDB or VistaDB.

It leaves relatively small footprint (no DLLs), it's a single-file db (a must for me), supports Unicode, BLOB compression, crypting, and technical limits seem impressing for a flat database. Moreover, support was good in few occasions when I needed it.

For cons, I have noticed it doesn't support nested transactions, but other than that, I had no problems.

Answer 10

As for size, nothing beats SQLite.

when you refer about lack of documentation, i guess it's doc for DISQLite3. The SQLite docs are quite complete

Answer 11

The problem with (embedded) firebird is, that the database cannot reside on a network drive. Also, it is difficult to have a database on a read only drive (CD/DVD).

For some hacks around these limitations see the Delphi Wiki: http://delphi.wikia.com/wiki/Firebird_tipps

Answer 12

Take a look at NexusDB. Have used very successfully in the past.

Answer 13

NexusDB offers the full range from embedded, to full client/server / remote. Also SQL2003 compliant, I believe. I'm using it on a few projects, and am very pleased so far, and the fact that it can work in such a wide range of "scales" is a big plus (not having to learn another DB for scaled-up apps, etc).

Answer 14

Look at this embedded database comparison: http://sql-db.cz.cc/ , it can be helpful. Most of abovementioned products are presented there: Advantage, DBISAM, Firebird, MS SQL Server, and much more: Accuracer, Apollo, ElevateDB, NexusDB, TurboDB.

Answer 15

I am partial to Component Ace's Absolute DB. Although a commercial product ($), it is solid, easy to use, small footprint and well documented. If you are looking for a huge multi-user application, this is not the way to go, but if your multi-user needs are light (or non-existent) this is a solid option.

Answer 16

I'm using SQL Server Express and the ADO components. Works great. You can run the SQL Server Express install with commandline to hide the complexities from the users. You can also distribute a database that you load by filename. There are millions of SQL server users so solutions to any problems are easily found in the intertubes :-)

Answer 17

I did a websearch to find a fast database package for my Delphi Application. I wanted it to be completely contained in the executable with no external DLLs or libraries required. I originally found Accuracer by AidAim. They had posted how fast their database was and even gave comparisons with other similar packages to “prove” their point.

I wanted to believe their claims but I thought I'd search the web a bit more to find timings of other packages. I was very surprised to find a post at the Delphi discussion forums where a person asked what database to use, and there were 14 different suggestions. One of the responders had done his own timing comparisons and had found Accuracer to be quite slow compared to several others, which Accuracer had (conveniently) left out of their own comparison page.

The post, plus additional followup web research by me, led me to lean toward DISQLite3 , a product based on the Open Source SQLite program , but with enhancements to work in Delphi very quickly, with very small overhead, and with command-based calls - which I like. It is actively under development and will soon have an official Delphi 2009 version, although apparently the current version will work under D2009.

Addenum: DISQLite3 Version 2.0.0, released Nov 17, supports D2009.

Answer 18

I know MS access is a comparatively crap db (and expect to be shot down in flames here), but if only small data is needed it may have advantages if ms office is used anyway. For me it was a way to store program data with more flexibility than csv files which is a common approach for scientific code.

You can create an access db from delphi code without having ms office installed using ado & odbc driver (might be necesary to have an initial .accdb file without tables to copy from then populate, I can't remember this detail. not sure licensing situation doing this.

The .accdb extension can be changed to something else & the file password protected (to a limited degree) so its not immediately obvious to users its access if that's desired. I know a few commercial developers do this method & copied it myself. Found it easier to setup than sqlite, but maybe because I'd already used ado & access in the past.

Answer 19

I have used ScimoreDB. It has its quirks as they give it royalty free and it has its quirks in data types and with some installation issues. This was on a C# project.

Answer 20

如果绝对需要嵌入式，请查看DBISAM。

Answer 21

kbMemTable is a good candidate. Runs in memory, fast, multi-threadding. Used to be free.

Components4Developers

Answer 22

I have used DBISAM and kbMemTable on different occasions.

What I like about DBISAM is that it has great features, and is usually very reliable. I have used it in large databases, full-text search, read-only mode, CGIs and many other situations.

It is fairly large compared to kbMemTable or SQLite based components, though. And you can't have a single file per database (or even table) - depending on the situation, that is a major disadvantage.

kbMemTable is tiny and it's great for small amounts of data. Since it runs in memory, it has to be a small amount of data, of course.

One other option I've taken on a couple of my desktop apps is dumping the data directly from/to my object hierarchy using TWriter/TReader. This is by far that smallest option, and is absurdly fast compared to using a database. The data files are tiny, too.

It has all kinds of drawbacks, though - you have to code versioning in if you might want to ever add/change fields, unless it's in-memory it is even more complicated, no multi-user support at all, etc.

Answer 23

I have a database that I have to record 5 field data for every 20 sec for 10 days.. 3 field are integer , 1 field is double ( time ) and 1 field is string[5].

I am still using Delphi6 srv2 because of my components. Newer delphi versions are terrible at components that I have to spend thousands of dollars of money to rebuild my component library. Therefor delphi 6 is still best for real commertial applications that never version of delphis give many problems. At many points such as USB or comport readings so on... they release newer ones before previous versions never sit on market.

I have setup a code with Delphi6 what appends 43200 records at a table for test because I will deploy the table in application while it has 43200 records. I will shown all the data on DBChart.

Test result is below databases filled the tables by insert command with 43200 records

Dbisam = 34 sec,
ElevateDb = 11 sec,
AbsoluteDB = 45 sec,
SQLlite = 32 Minute,
Firebird = 12 min,
MSSQL12 localDB = 28 Minute,
Easy table = 8 minute,
BDE = Blocked ,

I havent tested oracle , blackfish , sysbase, nexsusDb etc.. but it seems they will also very slow. I have connected with DBChart and only elevateDb and absoluteDB has loaded 43200 records on DBchart in exceptable time such as 7~10 secs. Other all taken minutes. So slower databases always needs coding tricks to succeed in some real jobs..

I have tested their search speed as well by locate command that unfortunatly the server based databases are always slower in.

MSSQL and SQLLite3 are extremely difficult to manage in to delphi that they made me very tired.

These are my test results
At the end I decided to use AbsoluteDB, Dbisam and Elevate. I have thrown the rest off the PC .

Elevate software doesnt support recno function that requires extra codes at runtime to manage. This makes the database slower Other bug is with Elevate software is autoinc fields. There is no way to reset it . Therefore I have not chosen the Elevat software even it is the fastest database. They say many good functions but how many of them we use it in fact . They just left the most important functions not supported but fixed many many unnecessary functions. and it seems since 8 years there is no any advantage either.

If you want to see with your own eye pls just try and see..

I am thinking between two now absolute DB or DBisam4

Answer 24

Firebird embedded is our #1 choice as well. And the suite Unified Interbase v2.0 with it. A great and stable solution!

Answer 25

when it comes to embedded databases the first question is : is it multiuser ? Actually,who needs a database that does not allow multiple connections (read&write) to it ? I have tried (intensly) all mentioned databases and found only one that actually functions the way it should. And that is Accuracer. The only pity with accuracer is that its a three man band and chronic lack of proper support. It also is mainly static in development as we have seen no real features in years.Not surprising since only one person actually develops it. It seems they are living on old fame. Users praise reflect that (usually 10 years old comments). For a single user experience I would recommend Absolute Database. As for major players I would recommend SQL Server from Microsoft. Oracle has become a bloatware and is slowly dying out.

ps what is nice in accuracer is that their embedded database functions just like full blown server. It locks only current record if its in use while the rest functions normally. Nice database. Pity only it is stagnant.

Answer 26

Firebird all the way. Does pretty well everything and so far version 2.1 is very solid.

Answer 27

FireBird offers the opportunity to scale up to multi-users sometime down the line, or if you need concurrency (if your application goes multi-threaded).

SQLite is quite unrivaled if you only need single-user access, no other database comes close to it on any aspect, be it performance, convenience, SQL support or stability.

Answer 28

Firebird确实很棒，而且占地面积很小，因此您可以使用嵌入式工具，并且可以向上扩展以供许多用户使用，并且unicode不能很好地工作。我将devart组件与delphi 2009和FIB plus一起用于delphi 6/7（其2009和unicode版本）还没准备好还很糟糕）

Answer 29

Hmmm, no one has recommended the BDE - I wonder why that is ;-)

BlackFishSQL is another possibility, although I haven't tested in depth as yet.