Change Field Values

[dblarch]

I have a field in a table which contains a list of integers used as IDs. I'd like to offset them by a fixed amount as follows: 1->201, 2->202, 3->203, etc. Is this possible in a live query? If not is there some code that will accomplish the task?

Thanks,

DblArch

 

[TonyMcGuire]

var
qbe query
endvar

qbe=query

tablename.db | fieldname |
| _a, changeto _a+200 |

endquery
qbe.executeqbe()

If the table is keyed, you might want to remove the key first. But the above should work either way.

Tony McGuire

http://www.thedbcommunity.com

 

[dblarch]

Thanks Tony,

Paradox 10 Help alludes to "CHANGETO" but offers no example of the straightforward and quite helpful query you supplied which was perfectly suited to my problem. The "_a" in your query has the same form as the join string used when querying on two or more tables linked by a common field. Does this string arrangement have even more uses?

Thanks again,

DblArch

 

[TonyMcGuire]

Example Elements are simply a way to reference a field.

You can 'join' tables with them, and you can use them to reference fields in the same table, or different tables, in the query.

They are helpful for selecting things based on a field, as well as performing calculations.

Or, as in this case, to reference a field to be changed as well as a reference of the calculation to perform.

A couple of examples:

query

tablename.db | fieldOne | fieldTwo |
| _a | changeto _a+200 |

endquery

query

tablename.db | fieldOne | fieldTwo |
| _a | _b, changeto _a+_b |

endquery


Tony McGuire

http://www.thedbcommunity.com