Python basics

At least to start with RCDB conditions, to put values and to get them back:

#Python

from datetime import datetime
from rcdb.provider import RCDBProvider
from rcdb.model import ConditionType

# 1. Create RCDBProvider object that connects to DB and provide most of the functions
db = RCDBProvider("sqlite:///example.db")

# 2. Create condition type. It is done only once
db.create_condition_type("my_val", ConditionType.INT_FIELD, "This is my value")

# 3. Add data to database
db.add_condition(1, "my_val", 1000)

# Replace previous value
db.add_condition(1, "my_val", 2000, replace=True)

# 4. Get condition from database
condition = db.get_condition(1, "my_val")

print condition
print "value =", condition.value
print "name  =", condition.name

The script result:

<Condition id='1', run_number='1', value=2000>
value = 2000
name  = my_val

More actions on objects:

# 5. Get all existing conditions names and their descriptions
for ct in db.get_condition_types():
    print ct.name, ':', ct.description

The script result:

my_val : This is my value

# 6. Get all values for the run 1
run = db.get_run(1)
print "Conditions for run {}".format(run.number)
for condition in run.conditions:
    print condition.name, '=', condition.value

The script result:

my_val = 2000

The example also available as:

$RCDB_HOME/python/example_conditions_basic.py

It is assumed that 'example.db' is SQLite database, created by create_empty_sqlite.py script. To run it:

python $RCDB_HOME/python/create_empty_sqlite.py example.db python $RCDB_HOME/python/example_conditions_basic.py '''(!)''' note that to run the script again you probably have to delete the database rm example.db

The next sections will cover this example and give thorough explanation on what is here.

Command line tools

Command line tools provide less possibilities for data manipulation than python API at the moment.

export RCDB_CONNECTION=mysql://rcdb@localhost/rcdb
rcnd --help                            # Gives you self descriptive help
rcnd -c mysql://rcdb@localhost/rcdb    # -c flag sets connection string from command line instead of environment
rcnd                                   # Gives database statistics, number of runs and conditions
rcnd 1000                              # See all recorded values for run 1000
rcnd 1000 event_count                  # See exact value of 'event_count' for run 1000

# Creating condition type (need to be done once)
rcnd --create my_value --type string --description "This is my value"

# Write value for run 1000 for condition 'my_value'
rcnd --write "value to write" --replace 1000 my_value

# See all condition names and types in DB
rcnd --list

More information and examples are in #Command line tools section below.