[fpc-devel] SQlite dataset small fix

Luiz Américo pascalive at bol.com.br
Mon Oct 31 02:56:27 CET 2005

Bogusław Brandys wrote:
> Hello,
> Attached diff for sqliteds.pas and sqlite3ds.pas allow to properly
> recognize CHAR(X) and VARCHAR(X) types for sqlite dataset.
> It is really small fix done because I have such sqlite database with
> defined VARCHAR fields (although sqlite is typeless)
> It is using Pos function to find if CHAR is somewhere inside field type
> and to find () and get X value .Maybe not too clever but I could'nt find
> any better/simpler way.

A better/simpler way would be to treat any field declaration that 
doesn't fit in the hardcoded ones as a String (VARCHAR) field.

Until fpc 2.0.0 version, TSqliteDataset used this aproach. This allowed 
to use sqlite databases created outside TSqliteDataset. The drawback is 
that the user would expect that a "NUM" field be treated as a Integer or 
a Float when it would not. So, to avoid this situation, if a field type 
declaration is not recognized an error is throw and the dataset is not 

The solution is to migrate the datafile to the table layout used by 
TSqliteDataset programatically. I'll do routine/program that does it, if 
you want please give a week. I'll post the code in the fpc list.

As the TSqliteDataset maintainer i'm against this change, but the final 
decision is to the RTL developers, most notable Michael Van Canneyt

- FieldSize in String fields should always be 0 - I will fix it later
- Also note that sqlite treats CHAR()/VARCHAR[()]/Whatever the same way.


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