Database documentation

Database schema

A current database schema of LimeSurvey CE version 5.4.x (as of 2022-09-15) can be viewed under https://manual.limesurvey.org/limesurvey/LimeSurvey-5.x-database-schema.html

List of tables

Without prefix, these are all persisten tables, as of 2022-09-15:

answer_l10ns                     
answers                          
archived_table_settings          
assessments                      
asset_version                    
boxes                            
conditions                       
defaultvalue_l10ns               
defaultvalues                    
expression_errors                
failed_login_attempts   
failed_emails         
group_l10ns                      
groups                           
label_l10ns                      
labels                           
labelsets                        
map_tutorial_users               
notifications                    
participant_attribute            
participant_attribute_names      
participant_attribute_names_lang 
participant_attribute_values     
participant_shares               
participants                     
permissions                      
permissiontemplates              
plugin_settings                  
plugins                          
question_attributes              
question_l10ns                   
question_themes                  
questions                        
quota                            
quota_languagesettings           
quota_members                    
saved_control                    
sessions                         
settings_global                  
settings_user                       
survey_links                     
survey_url_parameters            
surveymenu                       
surveymenu_entries               
surveys                          
surveys_groups                   
surveys_groupsettings            
surveys_languagesettings         
template_configuration           
templates                        
tutorial_entries                 
tutorial_entry_relation          
tutorials                        
user_groups                      
user_in_groups                   
user_in_permissionrole           
users

archived_table_settings

The table used to store the state of encryption set for the curently archived table that will be needed to restore them to the appropriate status.

Columns:

Name	Type	Null	Key	Default	Extra	Description
id	int(11)	NO	PRI	NULL	auto_increment
survey_id	int(11)	NO		NULL
user_id	int(11)	NO		NULL
tbl_name	varchar(255)	NO		NULL		The table the setting belongs to (e.a. old_survey_367888_timings_20210809100945, old_survey_367888_20210624125341, old_tokens_367888_20210809100945)
tbl_type	varchar(10)	NO		NULL		The type of the table (timings,response,token)
created	datetime	NO		NULL		The date the entry was created
properties	text	NO		NULL		The default settings for the current table as json (varies based on which type) e.a. tokenencryptionoptions. The json can contain only 'unknown' which means the status of the encryption could not determined during implementation of the table.
attributes	text	YES		NULL	NULL	custom settings that are not stored together with default settings like "attributedescriptions". The json can contain only 'unknown' which means the status of the encryption could not determined during implementation of the table.

question_themes

Also see https://manual.limesurvey.org/Question_themes.

Columns:

Name	Type	Null	Key	Default	Extra	Description
id	int(11)	NO	PRI	NULL	auto_increment
name	varchar(150)	NO	MUL	NULL
visible	varchar(1)	YES		NULL
xml_path	varchar(255)	YES		NULL		Either relative to app root dir OR absolute path
image_path	varchar(255)	YES		NULL
title	varchar(100)	NO		NULL
creation_date	datetime	YES		NULL
author	varchar(150)	YES		NULL
author_email	varchar(255)	YES		NULL
author_url	varchar(255)	YES		NULL
copyright	text	YES		NULL
license	text	YES		NULL
version	varchar(45)	YES		NULL
api_version	varchar(45)	NO		NULL
description	text	YES		NULL
last_update	datetime	YES		NULL
owner_id	int(11)	YES		NULL		User id of owner
theme_type	varchar(150)	YES		NULL		Always "question_theme" right now; TODO: Delete? theme type is assumed from database table
question_type	varchar(150)	NO		NULL		Single-letter question type
core_theme	tinyint(1)	YES		NULL		Core theme = included in main git repository
extends	varchar(150)	YES		NULL		If this theme extends another theme (can be both core and user uploaded theme)
group	varchar(150)	YES		NULL		Question type group (array, single-choice, etc); used in the question type selector
settings	text	YES		NULL		JSON string; copied from metadata, but only subquestions, answerscales, hasdefaultvalues, asssessable, class (CSS). TODO: Move these five settings to <settings> section in config.xml.

failed_emails

Also see the Failed email notifications manual page

Columns:

Name	Type	Allow Null	Key	Default	Extra	Description
id	int(11)	NO	PRI	NULL	auto_increment
surveyid	int(11))	NO		NULL		The survey ID
responseid	int(11)	NO		NULL		The response ID
email_type	varchar(200)	NO		NULL		The email type, for Detailed Email Notification('admin_responses'), for Basic admin notification('admin_notification')
recipient	varchar(320)	NO		NULL		The email address of the recipient
language	varchar(20)	NO		NULL		Language code of the email
error_message	text	YES		NULL		The error message from mailer
created	datetime	NO		NULL		When the email failed the first time
status	varchar(20)	YES		NULL		The current status of the entry 'SEND FAILED' or 'SEND SUCCESS'
updated	datetime	YES		NULL		When the failed email entry as updated last.
resend_vars	text	NO		NULL		json encoded values needed to resend the email [message_type,Subject,uniqueid,boundary[1],boundary[2],boundary[3],MIMEBody]