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Re: [Help-glpk] Database connectivity in MathProg
From: |
Andrew Makhorin |
Subject: |
Re: [Help-glpk] Database connectivity in MathProg |
Date: |
Tue, 12 Feb 2008 14:49:25 +0300 |
> Especially when connecting to data sources like csv files, or
> spreadsheets which do not contain meta information identifying keys it is
> necessary that MathProg defines which columns are the keys if UPDATE and
> INSERT are to be used.
> This is why AMPL is identifying key columns with brackets [] in the table out
> statement.
> Implementing a syntax
> table t OUT ... : {...}->[k ~ K, ...], ...;
> will not cause significantly more effort for the programmer then
> table t {...} OUT ... : k ~ K, ...;
> but will convey the necessary information to uniquely identify the key
> columns for the data base interface.
> If this looks more appealing to You, You might use:
> table t {...} OUT ... : [k ~ K, ...], ...;
I could suggest other solution: the driver obtains information about key
fileds, say, from strings or column names; for example, if a column name
begins with '_', it could mean that this is the key column (in which
case '_' is just ignored).
In any case I think to implement the table feature as simply as
possible, because many details are still unclear and should be
implemented later, if necessary.
- Re: [Help-glpk] Database connectivity in MathProg, (continued)
- Re: [Help-glpk] Database connectivity in MathProg, xypron, 2008/02/08
- Re: [Help-glpk] Database connectivity in MathProg, Andrew Makhorin, 2008/02/09
- Re: [Help-glpk] Database connectivity in MathProg, Andrew Makhorin, 2008/02/09
- Re: [Help-glpk] Database connectivity in MathProg, glpk xypron, 2008/02/09
- Re: [Help-glpk] Database connectivity in MathProg, Andrew Makhorin, 2008/02/09
- Re: [Help-glpk] Database connectivity in MathProg, glpk xypron, 2008/02/10
- Re: [Help-glpk] Database connectivity in MathProg, Andrew Makhorin, 2008/02/10
- Re: [Help-glpk] Database connectivity in MathProg, glpk xypron, 2008/02/10
- Re: [Help-glpk] Database connectivity in MathProg, Andrew Makhorin, 2008/02/10
- Re: [Help-glpk] Database connectivity in MathProg, glpk xypron, 2008/02/11
- Re: [Help-glpk] Database connectivity in MathProg,
Andrew Makhorin <=
- Re: [Help-glpk] Database connectivity in MathProg, Andrew Makhorin, 2008/02/10
- Re: [Help-glpk] Database connectivity in MathProg, glpk xypron, 2008/02/11
- Re: [Help-glpk] Database connectivity in MathProg, Andrew Makhorin, 2008/02/16
- Fwd: Re: [Help-glpk] Database connectivity in MathProg, glpk xypron, 2008/02/17
- Re: [Help-glpk] Database connectivity in MathProg, Andrew Makhorin, 2008/02/17
- Re: [Help-glpk] Database connectivity in MathProg, glpk xypron, 2008/02/17
- Re: [Help-glpk] Database connectivity in MathProg, Andrew Makhorin, 2008/02/10
- RE: [Help-glpk] Database connectivity in MathProg, Meketon, Marc, 2008/02/10
- Re: [Help-glpk] Database connectivity in MathProg, Andrew Makhorin, 2008/02/10