pg_select
pg_select
Synopsis
pg_select dbHandle queryString arrayVar queryProcedure
Description
pg_select submits a SELECT query to the
PostgreSQL backend, and executes a
given chunk of code for each tuple in the result.
The queryString
must be a SELECT statement. Anything else returns an error.
The arrayVar
variable is an array name used in the loop. For each tuple,
arrayVar is filled in
with the tuple field values, using the field names as the array
indexes. Then the
queryProcedure
is executed.
In addition to the field values, the following special entries are made in the array:
- .headers
A list of the column names returned by the SELECT.
- .numcols
The number of columns returned by the SELECT.
- .tupno
The current tuple number, starting at zero and incrementing for each iteration of the loop body.
Usage
This would work if table table has fields control and name
(and, perhaps, other fields):
pg_select $pgconn "SELECT * FROM table" array {
puts [format "%5d %s" $array(control) $array(name)]
}