A popular open-source embeddable (i.e. non client-server) RDBMS implemented as a C library.

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1answer
177 views

How to define the table structure for measured data in sqlite

I have an embedded system with an sqlite database. How should I define the table structure for the measured data from 4 sensors? Each sensor give us every second an numeric measured value. The ...
0
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0answers
166 views

SQLite 3 Tree List Without CTE

I adapted a SQL statement to work with SQLite 3. But unfortunately Common Table Expressions and WITH clause works only in SQLite 3.6 ahead, but the users of my Open Source application are using SQLite ...
1
vote
1answer
26 views

How to optimize search restricted by boolean column?

I want to optimize a query1 of the form SELECT yid, xid FROM x WHERE is_principal; Here, is_principal is a non-null boolean column of x. If I run EXPLAIN QUERY PLAN on this query, the output I get ...
2
votes
1answer
220 views

How to enforce an “exactly-one-per-group” constraint?

I have a table x that I've defined like this: CREATE TABLE x ( xid INTEGER NOT NULL PRIMARY KEY, yid INTEGER NOT NULL REFERENCES y(yid), is_principal BOOLEAN NOT NULL ); This definition ...
1
vote
1answer
89 views

Will my sqlite database occupy less space if I insert nulls instead of zeros

I have a table where most of the values inserted in one of the columns are 0. Should the database be smaller if I insert nulls instead of zeros?
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1answer
117 views

SQL: how to scan an entire table sequentially from top to bottom

How do I 'scan' all the way through an SQL table (approx 120k rows/50 columns) from the top/beginning, all the way to the bottom/end, and for each row found, I will need to 'do something'. The 'do ...
3
votes
1answer
95 views

Store different rows type in single table

I'd like to create a DB to store different rows type. It will be kind of event list with time stamp. So I'd like to have an Event table with relations to other tables - each table will be a row type ...
1
vote
1answer
83 views

Child records under the parent record in SQLite [closed]

I have two tables for Billing, one Bill_Master and other is Bill_Detail. The records in both tables are as follows... **BILL_MASTER** id party bill_amount 1 abc 500 2 def ...
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vote
2answers
149 views

New to databases - does my ERD reflect good database design?

I'm making a database to hold data for a media player that I'm working on. Originally, I thought to use one table with the fields: {filePath,artist,title,album,track_number,length,date,artworkUrl} ...
0
votes
1answer
404 views

DBEAVER: SQL error or missing database (near “,”: syntax error)

I'm using DBeaver (because Base only works on OS X) to work with an SQLite database. When I attempt to execute the following query, I get the error message 'SQL error or missing database (near ",": ...
-1
votes
1answer
58 views

Creating Triggers to insert into a table where the table is altered by other application

I have a database in my local machine which is actually updated by an online application. I want to create triggers for a particular table ( say table1) such that it inserts values (From Table1) ...
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0answers
63 views

Continuously copying an SQLite table

I have a SQLite database associated with an online application (Skype) on my computer, which is often changed by that application when I am using Internet. These are the columns of the database: ...
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0answers
314 views

Migrate from SQLite to MySQL (then back)

For various reasons, I must use a SQLite database with a local application. However, I wrote a Flask app that enables users to more easily classify items in the database, and it runs very slow on ...
0
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0answers
313 views

insert record to child table which doesn't map to parent table - possible?

Actually I've 2 relevant questions: insert record to child table which doesn't map to parent table - possible? ON DELETE NO ACTION - when a record in parent table is deleted, it should affect ...
0
votes
1answer
2k views

SQLite - No Such Column TABLE.ROWID

I'm using this query on SQLite 3: Select Message.messageContent, Message.messageDateTime FROM Message INNER JOIN (Contact INNER JOIN contact_m2m_message ON Contact.contactID = ...
0
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1answer
29 views

Retrieve index column

I have this index schema: CREATE index comments_idx ON comments (books) How can I retrieve column name ("books") through SQL query?
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2answers
46 views

How to use relationships to extract data via select

Disclaimer: Novice in SQL I have 3 tables. There is one "major" table (labeled used_for_lookup below) used to do look-ups on and the other two (labeled fid_table and did_table below) are foreign keys ...
3
votes
1answer
51 views

Finding records not present across 3 tables - Sqlite3

From the diagram provided, what I'm trying to achieve is to get all the Users of a particular workspace that are NOT associated with a task within user_task. user_workspace table contains two FKs: ...
0
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2answers
566 views

Group by + Order by Behavior Explanation? [duplicate]

Suppose I have: Product(_id,Name) Provider(_id,Name) Provides(ProductId, ProviderId, Price) If I want to obtain the providers who sell the most expensive products, and whose name starts with A. ...
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0answers
28 views

Unable to open MONyogs

I was trying to run through the docs for manually working with the MONyog internal sqlite dbs for purposes of configuration automation. At the point trying to open the data file I get an error $ ...
0
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2answers
180 views

sqlite group_concat error while executing query

I have table: CREATE TABLE www ( Col_1 VARCHAR, Col_2 VARCHAR ); select count(*) from www; --1496 And I have error: "Error while executing query: aggregate function are not allowed in ...
0
votes
1answer
69 views

SQLITE table joining with group

MESSAGE TABLE USERS msg_id | msg_to | msg_from | msg_body | msg_date user_id | user_name 1 1 2 hi 22/1/14 ...
6
votes
1answer
182 views

Many-to-many relationship with attributes

I'm working on a project where I need a book database. The problem is as follows: A book can be related to multiple people (authors, editors, traslators, etc.). Then a person may contribute to ...
1
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1answer
3k views

Joins in Update statement in sqlite

CREATE TABLE Table_1 ( Id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL , EmailId VARCHAR ) INSERT INTO Table_1 VALUES (1,'raj@gmail.com'); INSERT INTO Table_1 VALUES (3,'test@gmail.com'); ...
0
votes
1answer
2k views

What's a good workbench tool for sqlite similar to MySQLWorkbench for MySQL? [closed]

What's a good workbench tool for sqlite similar to MySQLWorkbench for MySQL? I'm used to MySQLWorkbench for working with MySQL databases. Now I have some sqlite databases to work with and would ...
1
vote
1answer
910 views

How to get the rowid in a TRIGGER for another table in SQLite

Given the below schema CREATE TABLE Item ( _id INTEGER NOT NULL, name NVARCHAR NOT NULL, parent INTEGER NULL CONSTRAINT fk_Recursive ...
1
vote
1answer
769 views

Cartesian product of two tables not working as expected in MySQL but fine with SQlitee?

I was practising some sql joins and decided to create a schema online rather than using my local database on sql fiddle. My schema is pretty simple table 1 (5 entries): (emp->{id,name,dep}) table ...
0
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1answer
1k views

How to select non unique values from 1 column if a value doesn't exist in column 2

I have a table containing (among other things) 2 integer values, neither of which are unique. See below for example data: --------------- | a | b | --------------- | 1 | 1 | ...
2
votes
2answers
70 views

Strategy to find the unique bivariate polynomials

I have table that stores Tutte polynomials of a large set of graphs. These are bivariate polynomials with integer coefficients. An example of a polynomial taken from Wikipedia is: Since the ...
1
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2answers
2k views

Improving `GROUP BY` query performance in sqlite3

I have a little web-application that is using sqlite3 as it's DB (the db is fairly small). Right now, I am generating some content to display using the following query: SELECT dbId, dlState, ...
0
votes
1answer
66 views

Query executes fast, but keeps the table locked for some time

Executing the following query is very fast (75ms), but removing the comment from the last row it becomes slow (2.5s), and the time increases exponentially with the number of rows in the table. It ...
0
votes
2answers
126 views

One table with a flag or two tables

I have a problem with the design of a database: In my Android application i need to store the upload (the status, so if the file is in upload it will report the % of the upload) of a file and a list ...
2
votes
1answer
252 views

File database vs application server database for concurrent performance & bulk data

I asked a question about Ripple's database implementation, and received this response: The ripple server uses SQLite for structured data and a configurable "back end" for unstructured "bulk" ...
1
vote
1answer
487 views

SQLite and Write Ahead Logging: why so large files

I have been doing some operations on SQLite databases recently. The other day I ran a command to DELETE a bunch of rows from a 1GB database file and the WAL file got over 8GBs at which point it ...
0
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1answer
148 views

PHP SQLite Admin is running on PHP 5.4

I tried phpsqliteadmin But it doesn't seem to work anymore on PHP 5.4. There are several alternatives, but none of them seems to be "The One" that is maintained and widely used. Is there a standard ...
2
votes
1answer
131 views

Rewrite sqlite trigger to postgresql

Can you help me please with this problem? I need rewrite this simply trigger from sqlite to PostgreSQL format: In sqlite: CREATE TRIGGER connections_INSERT_update_connection_root_trg ...
2
votes
2answers
166 views

Create a result for a line chart with dates

I have this table in SQLite which I use to record the risk level identified in vulnerability assesments according to the day the scan was performed. This table looks like this: Scan Date | Risk ...
0
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0answers
35 views

Approaching multiple values in same column

I'm developing an Android-application that scrapes the schedule for my university and presents it nicely since the current system is a nightmare. I'm processing a lot of data and it gets down to ...
0
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1answer
237 views

Foreign key double inheritance SQLITE

I'm designing a domotic system database and I'm trying to figure out how to represent two foreign keys. This is the cardinality I want. Consider 1...N Areas (rooms, halls, kitchens, etc.): Area 1 - ...
1
vote
2answers
6k views

join for between multiple tables without common fields

table E : id, title, datetime table L : id, place, xpos, ypos table M : id, title, datetime, contact, agenda table ER : parentid, childid, parenttype, child type data in ER : e.id, l.id, e, l -> E ...
1
vote
1answer
103 views

Joining three tables

I have a question Find the titles of all movies not reviewed by Chris Jackson Where the relations are 3 movie(mID, title, year, director), reviewer(rID, name), rating(rID, mID, stars, ratingDate) ...
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2answers
115 views

Problem in Nested Query [closed]

I have a query like this SELECT m.title FROM Movie AS M WHERE (SELECT MAX(r.stars) FROM rating AS r WHERE r.mID = M.mID); I want to show the MAX(r.stars) in my result set, what am I doing wrong?
0
votes
1answer
1k views

Database design for mobile app

At first I would like to say hello to all of you, since it is my first post here on DB Administrators. I am writing an app which store drinks and their data. At the beginning it was storing all in ...
1
vote
1answer
4k views

First time using an Index - SQLite / Android

I'm creating a SQLite Database for Android. I can do fairly simple SQL, but I haven't used an index before. I'm working on a table with >150,000 records and I've never dealt with a database so large. ...
0
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2answers
180 views

How to optimize query

I'm using SQLite3 and the following query, It seems like there should be a better performing way to write this query; Is there? Select Name, Sum(Case When Used ...
0
votes
1answer
957 views

nesting MAX for SELECT

I have a table, containing TV series episodes: series: | series_id | season | episode | title | 1 | 1 | 18 | xxx | 1 | 2 | 3 | xxy | 3 | ...
1
vote
1answer
3k views

Why does SQlite return incorrect sum?

CREATE TABLE "Test" ("ItemQty" DOUBLE NOT NULL ); Insert Into Test VALUES (1.4); Insert Into Test VALUES (1.4); Insert Into Test VALUES (1.4); Insert Into Test VALUES (1.4); Insert Into Test VALUES ...
2
votes
2answers
138 views

EAV-like table with both primary column pointing to the same foreign column

Background: I'm a programmer who, while had to work with simple databases several times, never had to work with complex ones. I.e. I'm proficient with basic stuff, but clueless about advanced features ...
0
votes
1answer
410 views

No such column error jdbc

Suppose I have a table: SERVICE={SID,NAME,PORT} and with the help of a Java program, I want to select the SID of the known port with the help of a SQL query: Select SID from SERVICE ...
2
votes
1answer
83 views

What does 'Vacuum' do in Menial's Base 2 application?

I've had a look at the help documentation for Base 2, as well as Menial's product page, but haven't found an answer there. I've even clicked on the vacuum button and not noticed any change. What does ...