# pg_result -getTuple returns a Tcl list containing the result column values
# from a single row (tuple), selected by a zero-based row number argument.
puts "Result is: [pg_result $result -getTuple 0]

Output:

Result is: 1 {Mount Karangetang} Indonesia 2001-01-25

# pg_result -tupleArray assigns values from one row of the query to an array.
# The desired row is selected by a zero-based row number argument.
# The array indexes are the column names.
pg_result $result -tupleArray 2 MyArray
parray MyArray

Output:

MyArray(id)            = 3
MyArray(last_eruption) = 1996-03-10
MyArray(location)      = Alaska
MyArray(volcano)       = Akutan

# pg_result -assign assigns the entire query result - column values from
# all rows - to a single array, indexed by the row number (starting at zero),
# and the column name, with the parts of the array index separated by a comma.
pg_result $result -assign MyArray
parray MyArray

Output:

MyArray(0,id)            = 1
MyArray(0,last_eruption) = 2001-01-25
MyArray(0,location)      = Indonesia
MyArray(0,volcano)       = Mount Karangetang
MyArray(1,id)            = 2
MyArray(1,last_eruption) = 1997-07-12
MyArray(1,location)      = Japan
MyArray(1,volcano)       = Hakkoda
MyArray(2,id)            = 3
MyArray(2,last_eruption) = 1996-03-10
MyArray(2,location)      = Alaska
MyArray(2,volcano)       = Akutan
MyArray(3,id)            = 4
MyArray(3,last_eruption) = 1996-04-04
MyArray(3,location)      = Nicaragua
MyArray(3,volcano)       = Momotombo

# pg_result -list returns a Tcl list containing the entire query result.
# The list items are in row-major, column-minor order.
puts "Result is: [pg_result $result -list]

Output (line-wrapped for presentation):

Result is: 1 {Mount Karangetang} Indonesia 2001-01-25 2 Hakkoda Japan
  1997-07-12 3 Akutan Alaska 1996-03-10 4 Momotombo Nicaragua 1996-04-04

# pg_result -llist returns a Tcl list of lists containing the entire query
# result.  Each item in the outer list is for one row of the query result,
# and each inner list contains the column values for that row.
puts "Result is: [pg_result $result -llist]

Output (line-wrapped for presentation):

Result is: {1 {Mount Karangetang} Indonesia 2001-01-25} {2 Hakkoda Japan
  1997-07-12} {3 Akutan Alaska 1996-03-10} {4 Momotombo Nicaragua 1996-04-04}

# pg_result -assignbyidx is similar to -assign in that it assigns all the
# values from all the rows in the query to a single array, but it forms
# the array indexes using the value of the first column of the query result
# (typically the table primary key column), followed by the field names,
# followed by an optional suffix. Note that the first column of the result
# is not stored in the array - it is used as part of the index for the
# other values in each row.
# In this example, the optional suffix is not used.
pg_result $result -assignbyidx MyArray
parray MyArray

Output:

MyArray(1,last_eruption) = 2001-01-25
MyArray(1,location)      = Indonesia
MyArray(1,volcano)       = Mount Karangetang
MyArray(2,last_eruption) = 1997-07-12
MyArray(2,location)      = Japan
MyArray(2,volcano)       = Hakkoda
MyArray(3,last_eruption) = 1996-03-10
MyArray(3,location)      = Alaska
MyArray(3,volcano)       = Akutan
MyArray(4,last_eruption) = 1996-04-04
MyArray(4,location)      = Nicaragua
MyArray(4,volcano)       = Momotombo

# pg_result -dict returns all the values from all the rows in the query
# result, similar to -assign, but it stores them in a Tcl dictionary rather
# than an array. This requires Tcl-8.5 or higher.
# The returned value is a two-level dictionary. The outer keys are row
# numbers starting from 0, and the inner keys are column names.
set MyDict [pg_result $result -dict]
dict for {i row} $MyDict {
  dict for {field value} $row {
    puts "MyDict.$i.$field = $value"
  }
}
puts "\nLocation from row 2: [dict get $MyDict 2 location]"

Output:

MyDict.0.id = 1
MyDict.0.volcano = Mount Karangetang
MyDict.0.location = Indonesia
MyDict.0.last_eruption = 2001-01-25
MyDict.1.id = 2
MyDict.1.volcano = Hakkoda
MyDict.1.location = Japan
MyDict.1.last_eruption = 1997-07-12
MyDict.2.id = 3
MyDict.2.volcano = Akutan
MyDict.2.location = Alaska
MyDict.2.last_eruption = 1996-03-10
MyDict.3.id = 4
MyDict.3.volcano = Momotombo
MyDict.3.location = Nicaragua
MyDict.3.last_eruption = 1996-04-04

Location from row 2: Alaska