In mysql2 gem, we can use this statement to make all query result symbolized
require 'mysql2'
Mysql2::Client.default_query_options.merge!(symbolize_keys: true)
DB = Mysql2::Client.new(host: "localhost", username: "benchmarkdbuser", password: 'benchmarkdbpass')
DB.select_db('hello_world')
res = DB.query "SELECT id, message FROM Fortune"
rows = res.map { |row| row }
# [{id: 1, message: 'bla'}] --> id and message are symbols, not strings
how to do this on pg gem?
require 'pg'
DB = PG::Connection.new('localhost',5432,nil,nil,'hello_world','benchmarkdbuser','benchmarkdbpass')
res = DB.query "SELECT id, message FROM Fortune"
rows = res.map { |row| row }
# [{"id" => 1, "message" => "bla"}] --> id and message are strings, not symbols
If there is no native way:
h_to_sym = ->(row){ row.keys.each_with_object({}) { |k, o|
o[k.to_sym] = row[k].is_a?(Hash) ? h_to_sym.(row[k]) : row[k] }
}
p res.map.with_object([]) { |row, h| h << h_to_sym.(row) }
This also supports joined models.
Related
I would like to iterate an array that has a database table names, I would like to create a hash like this:
{"table1"=>[column1,...,columnN],"table2"=>[column1,...,columnM]...}
This is what I did so far:
arr_table_names = ['table1','table2','table3']
arr_table_names.each do |table|
rs = pg_conn.exec 'SELECT * FROM table WHERE Id=0'
column_names = rs.nfields
h = Hash.new{|hsh,key| hsh[key] = [] }
h[table].push ??? column_names ?? I don't know how in this line
end
I tried to use Sebastian's solution, but got a syntax error:
def check_tables_same_content(table1,table2)
result = %w[#{table1} #{table2}].each_with_object([]) do |table, arr|
arr << { table.to_sym => #pg_conn.exec("SELECT * FROM #{table} WHERE false").fields }
end
puts result2
end
check_tables_same_content('company','company2')
company.rb:21:in `exec': ERROR: syntax error at or near "#" (PG::SyntaxError)
LINE 1: SELECT * FROM #{table1} WHERE false
^
Note that I am not looking on how to return column names.
Use .map to create a new array and pass the block. This should work:
arr_table_names.map do |table|
rs = pg_conn.execute "SELECT * FROM #{table} WHERE Id=0"
{table => rs.fields}
end
Update, you wanted a hash with the table names as keys, and columns as values so:
arr_table_names = ['table1','table2','table3']
hash = {}
arr_table_names.each do |table|
rs = pg_conn.execute "SELECT * FROM #{table} WHERE Id=0"
hash[table] = rs.fields
end
Update 2, you want the row data as an array for each column(key) in the hash:
arr_table_names = ['table1','table2','table3']
hash = {}
arr_table_names.each do |table|
rows = pg_conn.execute "SELECT * FROM #{table}"
hash[table] = rows.entries.map(&:values)
end
I am trying to parse some output from a query using the mysql2 gem.
Previously, I would use:
response = JSON.parse(response.body)
a = response.map{|s| {label: s['Category'], value: s['count'].to_i} }
Now with the mysql2 query:
results = db.query(sql)
results.map do |row|
puts row
end
Output
{"Category"=>"Food", "count"=>22}
{"Category"=>"Drinks", "count"=>12}
{"Category"=>"Alcohol", "count"=>9}
{"Category"=>"Home", "count"=>7}
{"Category"=>"Work", "count"=>2}
'Category' to ':label' and 'count' to ':value'.
results = db.query(sql)
results.map do |row|
{label: row['Category'], value: row['count'].to_i} }
end
Desired Output
{:label=>"Food", :value=>22}
{:label=>"Drinks", :value=>12}
{:label=>"Alcohol", :value=>9}
{:label=>"Home", :value=>7}
{:label=>"Work", :value=>2}
You have two mistakes in your code:
1) You have two closing braces:
# HERE
# | |
results.map do |row| # V V
{label: row['Category'], value: row['count'].to_i} }
end
2) map() returns an array, and you don't save the array anywhere, so ruby discards it.
records = results.map do |row|
{label: row['Category'], value: row['count'].to_i }
end
p records
Here's the proof:
mysql> select * from party_supplies;
+----+----------+-------+
| id | Category | count |
+----+----------+-------+
| 1 | Food | 22 |
| 2 | Drinks | 12 |
+----+----------+-------+
2 rows in set (0.00 sec)
.
require 'mysql2'
client = Mysql2::Client.new(
host: "localhost",
username: "root",
database: "my_db",
)
results = client.query("SELECT * FROM party_supplies")
records = results.map do |row|
{ label: row['Category'], value: row['count'] }
end
p records
--output:--
[{:label=>"Food", :value=>22}, {:label=>"Drinks", :value=>12}]
Note that your output indicates the 'count' field is already an int, so calling to_i() is redundant.
I am trying to return a specific cell value based on two criteria.
The logic:
If ClientID = 1 and BranchID = 1, puts SurveyID
Using Ruby 1.9.3, I want to basically look through an excel file and for two specific values located within the ClientID and BranchID column, return the corresponding value in the SurveyID column.
This is what I have so far, which I found during my online searches. It seemed promising, but no luck:
require 'csv'
# Load file
csv_fname = 'FS_Email_Test.csv'
# Key is the column to check, value is what to match
search_criteria = { 'ClientID' => '1',
'BranchID' => '1' }
options = { :headers => :first_row,
:converters => [ :numeric ] }
# Save `matches` and a copy of the `headers`
matches = nil
headers = nil
# Iterate through the `csv` file and locate where
# data matches the options.
CSV.open( csv_fname, "r", options ) do |csv|
matches = csv.find_all do |row|
match = true
search_criteria.keys.each do |key|
match = match && ( row[key] == search_criteria[key] )
end
match
end
headers = csv.headers
end
# Once matches are found, we print the results
# for a specific row. The row `row[8]` is
# tied specifically to a notes field.
matches.each do |row|
row = row[1]
puts row
end
I know the last bit of code following matches.each do |row| is invalid, but I left it in in hopes that it will make sense to someone else.
How can I write puts surveyID if ClientID == 1 & BranchID == 1?
You were very close indeed. Your only error was setting the values of the search_criteria hash to strings '1' instead of numbers. Since you have converters: :numeric in there the find_all was comparing 1 to '1' and getting false. You could just change that and you're done.
Alternatively this should work for you.
The key is the line
Hash[row].select { |k,v| search_criteria[k] } == search_criteria
Hash[row] converts the row into a hash instead of an array of arrays. Select generates a new hash that has only those elements that appear in search_criteria. Then just compare the two hashes to see if they're the same.
require 'csv'
# Load file
csv_fname = 'FS_Email_Test.csv'
# Key is the column to check, value is what to match
search_criteria = {
'ClientID' => 1,
'BranchID' => 1,
}
options = {
headers: :first_row,
converters: :numeric,
}
# Save `matches` and a copy of the `headers`
matches = nil
headers = nil
# Iterate through the `csv` file and locate where
# data matches the options.
CSV.open(csv_fname, 'r', options) do |csv|
matches = csv.find_all do |row|
Hash[row].select { |k,v| search_criteria[k] } == search_criteria
end
headers = csv.headers
end
p headers
# Once matches are found, we print the results
# for a specific row. The row `row[8]` is
# tied specifically to a notes field.
matches.each { |row| puts row['surveyID'] }
Possibly...
require 'csv'
b_headers = false
client_id_col = 0
branch_id_col = 0
survey_id_col = 0
CSV.open('FS_Email_Test.csv') do |file|
file.find_all do |row|
if b_headers == false then
client_id_col = row.index("ClientID")
branch_id_col = row.index("BranchID")
survey_id_col = row.index("SurveyID")
b_headers = true
if branch_id_col.nil? || client_id_col.nil? || survey_id_col.nil? then
puts "Invalid csv file - Missing one of these columns (or no headers):\nClientID\nBranchID\nSurveyID"
break
end
else
puts row[survey_id_col] if row[branch_id_col] == "1" && row[client_id_col] == "1"
end
end
end
Is there an example in Ruby using rally_api how to set State of a feature as mentioned here?
Specifically, is there a way to query the ObjectID or the fully qualified path of state to use
"State" => "Developing"
instead of
"State" => "/state/<ObjectID>"
It is possible to query State, create a hash, and populate the hash with the query results, where State Name is the key and State _ref is the value:
state_results.each do |s|
s.read
state_hash[s["Name"]] = s["_ref"]
end
Then we can update a State:
features.each do |f|
field_updates={"State" => state_hash["Developing"]}
f.update(field_updates)
end
Here is a code example:
#rally = RallyAPI::RallyRestJson.new(config)
queryState = RallyAPI::RallyQuery.new()
queryState.type = :state
queryState.fetch = "true"
queryState.workspace = {"_ref" => "https://rally1.rallydev.com/slm/webservice/v2.0/workspace/11111" }
queryState.project = {"_ref" => "https://rally1.rallydev.com/slm/webservice/v2.0/project/22222" } #use valid OIDs
queryState.query_string = "(TypeDef.Name = \"Feature\")"
state_hash = Hash.new
state_results = #rally.find(queryState)
state_results.each do |s|
s.read
#puts "Ref: #{s["_ref"]}, Name: #{s["Name"] }, TypeDef: #{s["TypeDef"]}"
state_hash[s["Name"]] = s["_ref"]
end
query = RallyAPI::RallyQuery.new()
query.type = "portfolioitem/feature"
query.fetch = "Name,FormattedID"
query.workspace = {"_ref" => "https://rally1.rallydev.com/slm/webservice/v2.0/workspace/1111" }
query.project = {"_ref" => "https://rally1.rallydev.com/slm/webservice/v2.0/project/22222" } #use valid OIDs
query.query_string = "(Name = \"my feature\")"
results = #rally.find(query)
features = [];
results.each do |f|
f.read
puts "Current state of Feature #{f["FormattedID"]}: #{f["State"].to_s}"
features << f
end
features.each do |f|
field_updates={"State" => state_hash["Developing"]}
f.update(field_updates)
puts "Feature #{f["FormattedID"]} is now in State: #{f["State"].to_s}"
end
I'm creating a nested hash in ruby rexml and want to update the hash when i enter a loop.
My code is like:
hash = {}
doc.elements.each(//address) do |n|
a = # ...
b = # ...
hash = { "NAME" => { a => { "ADDRESS" => b } } }
end
When I execute the above code the hash gets overwritten and I get only the info in the last iteration of the loop.
I don't want to use the following way as it makes my code verbose
hash["NAME"] = {}
hash["NAME"][a] = {}
and so on...
So could someone help me out on how to make this work...
Assuming the names are unique:
hash.merge!({"NAME" => { a => { "ADDRESS" => b } } })
You always create a new hash in each iteration, which gets saved in hash.
Just assign the key directly in the existing hash:
hash["NAME"] = { a => { "ADDRESS" => b } }
hash = {"NAME" => {}}
doc.elements.each('//address') do |n|
a = ...
b = ...
hash['NAME'][a] = {'ADDRESS' => b, 'PLACE' => ...}
end
blk = proc { |hash, key| hash[key] = Hash.new(&blk) }
hash = Hash.new(&blk)
doc.elements.each('//address').each do |n|
a = # ...
b = # ...
hash["NAME"][a]["ADDRESS"] = b
end
Basically creates a lazily instantiated infinitely recurring hash of hashes.
EDIT: Just thought of something that could work, this is only tested with a couple of very simple hashes so may have some problems.
class Hash
def can_recursively_merge? other
Hash === other
end
def recursive_merge! other
other.each do |key, value|
if self.include? key and self[key].can_recursively_merge? value
self[key].recursive_merge! value
else
self[key] = value
end
end
self
end
end
Then use hash.recursive_merge! { "NAME" => { a => { "ADDRESS" => b } } } in your code block.
This simply recursively merges a heirachy of hashes, and any other types if you define the recursive_merge! and can_recusively_merge? methods on them.