iterate-clsql

Overview

This is an extension to iterate facility.

This extensions adds ability to iterate over results of queries to databases via CLSQL.

Code is in public domain.

Syntax

The following two clauses are added to iterate:

(for vars in-clsql-query query-expression &optional (on-database clsql:*default-database*))

(generate vars in-clsql-query query-expression &optional (on-database clsql:*default-database*))

• vars in either a single variable or a list of variables. If vars is a list, then it contains variable names which are bound to the values of columns. If vars is a single variable, then this variable is bound to the list of values of columns.
• query-expression is a valid CLSQL query expression. It may be a string or an object of type clsql:sql-expression. If CLSQL reader-syntax is enabled, then this syntax may be used here.

The for clause binds vars to values of columns of each successive row in result set of the query-expression.

Examples

• (iter (for (id name) in-clsql-query "select id, name from users" on-database *users-database*)
        (format t "User with ID of ~A has name ~A.~%" id name))

  or equivalent

  (iter (for columns in-clsql-query "select id, name from users" on-database *users-database*)
        (for (id name) = columns)
        (format t "User with ID of ~A has name ~A.~%" id name))

• (let ((id 11))
    (iter (for (x) in-clsql-query [select [id] :from :users :where [< [id] id]])
          (collecting x)))

Usage

To use this extensions, asdf-load the iterate-clsql system:

(asdf:oos 'asdf:load-op :iterate-clsql)

or add it to dependencies list of a system.

Installation

Download the tarball iterate-clsql-0.2.tar.gz and unpack it; make sure that it is loadable by ASDF. This means that the symlink to iterate-clsql.asd should be made into the directory that is in asdf:*central-registry*.

ChangeLog

• 3 January 2009 Fixed a small bug with default value of ON-DATABASE being evaluated and compile-time rather than run-time.

Contact information

Written by Dmitry Kalyanov. Contact by e-mail or by jabber (mo3r@jabber.ru).

Send bug reports to iterate-clsql-devel mailing list.

Announcements of new version are made to iterate-clsql-announce mailing list.

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