sqlupdate: Updates values in an SQL table
sqlupdate updates values in an existing table in an SQL
database. The rows to update are specified, as a normal
SELECT statement, using the select parameter.
Each column to update, and the value to write to it, are given using
the assign parameter.
Why not just use the database's own UPDATE statement? In most cases,
that would be a much better idea. However, using sqlupdate
you can write values using STILTS's
expression language, and hence take
advantage of its various functions, without having to embed them into
the database. SQL column names can be used as variables in these expressions,
in the same way that table column names are used as variables in
other commands such as tpipe.
This command can only be used if you have access to an SQL database via JDBC. The details of how to configure a JDBC connection to a database are discussed in Section 3.4 - obviously you will need a database to connect to and appropriate write permissions on it as well as the relevant drivers.
This is a somewhat specialised command, and several (database/driver-specific) things can go wrong with it. If you do not have a fairly good understanding of the database with which you are using it then you may run into problems (but then you'd be unlikely to have the permissions to do the updates in any case).