0
votes
1answer
77 views

Why can't modern databases have unlimited columns [on hold]

I am just curious as to why big open source and commercial RDBMSs can't, don't or won't implement unlimited columns per table? Is there a technical or business reason why this can't be done. MongoDB ...
0
votes
0answers
21 views

Receiving duplicate results in one condition of JOINED query

I always end up here when Googling for solutions, so I thought I'd cut out the middleman since I'm unable to fix this via searching/forums. It's my first time posting, so please forgive any faux pas ...
0
votes
1answer
26 views

MySQL: Rank by Department in an employees table

I need Mysql query to rank the hours used by each department in an employees table, but it just ranks all without taking into consideration the departments.
0
votes
1answer
33 views

to pivot or not to pivot - schema design question [closed]

I am implementing something similar to this schema http://www.databaseanswers.org/data_models/event_reservations/index.htm It occurs to me that the pivot table for Customer_Bookings would just keep ...
0
votes
2answers
36 views

Merging tables, but ignoring duplicate columns

I have two tables I want to merge: city1(id, city, state, zip, lat, lon, county) city2(id, city, state) The tables contain overlapping city and state, but not primary keys. I can't figure out how ...
0
votes
0answers
26 views

Query output conditional upon values in dataset

If the number column contains values 5 AND 6, AND the value X exists in the chr column, I would like to exclude rows with 10 in the test column. But, if the number column contains values 4 AND 5, AND ...
0
votes
1answer
30 views

Complex query on big table

I have a big user table (3M), of structure: age (int) country (FK) city (text) gender (text) active (bool) My objective is to run a search finding 15 users of given age area, gender, city and ...
1
vote
1answer
22 views

SQL : get rows from two tables relatively

I've two tables named categories and products. Simple structure is given below. categories cat_id cat_name 1 c1 2 c2 3 c3 products prod_id ...
0
votes
0answers
5 views

ODBC/MYSQL Insert a Query Result from ODBC to a databse in MYSQL [migrated]

I'm connecting to a cloud database through a ODBC connection: $conn=odbc_connect('MYDATABASE','',''); if (!$conn) { exit("Connection Failed: " . $conn); } $sql="SELECT DATETIME_ID, NAME, Sum(CNDROP) ...
0
votes
1answer
47 views

sql or hql query to find all parents of a particular record

I need a sql or hql query to find all parents of a particular record, that should work in oracle as well as mysql, for eg if I have the id: 201, the parents would be: 188, 187, 1. any help would ...
0
votes
0answers
27 views

mysql advanced query

I'm sorry for my English. I have a problem with db mysql. I have a table like this id|rat|time 1 |2 |12:00 2 |0 |12:55 3 |0 |13:05 4 |6 |13:45 5 |0 |14:00 6 |8 |15:00 7 |0 |16:30 8 |9 |17:00 ...
0
votes
1answer
25 views

Why does my MySql Savel replicate changes that are neither in binlog_do_db nor replicate_do_db?

I have a standard simple master slave replication that usually runs fine. But sometimes, all of a sudden, I get replication errors on the "phpmyadmin" table. I have explicitly only specified one ...
0
votes
0answers
15 views

Merge colums from two different databases using phpMyAdmin

Is there a way to: Replace all the data from database1 > table1 > column2 With Data from Database2 > table1 > column2 ONLY under the condition that the ID value in database1 > table1 > column1 ...
-4
votes
1answer
58 views

When you type an SQL query in interpreter, what does happen? [closed]

Actully this question is asked in an interview from me . When you type an SQL query in interpreter, what does happen? How is the query processed?
0
votes
2answers
51 views

Complex query: find all users who rated all the movies rated by user_id='1234'

So we have the following relational schema: users(user_id, ..) movies(movie_id, ..) ratings(user_id, movie_id, rate) So, we want to find all the users who have rated all the movies which are rated ...
0
votes
0answers
21 views

MYSQL Tables Join Filtering For Favorites

I am in need of some help figuring out the best way to join separate tables I am using. I am essentially trying to output a list of schools (first table in MYSQL) where one column is an empty star ...
0
votes
1answer
44 views

MySQL dies when trying to access a specific database

For some reason, whatever I do I cannot access one of my databases (through command line or through something like phpmyadmin). However, the application that depends on this database is not having any ...
0
votes
1answer
18 views

SQL: Repair With Keycache

Now my MySQL server running a REPAIR TABLE, table is almost 15gb size. Status - Repair with keycache. How I can restart REPAIR TABLE with normal (repair with sort) mode?
0
votes
2answers
30 views

Subquery or multiple left joins, or both?

I have two tables, for simplicity table1, with id as Primary key, and a field name, and table2 with the same. Each table has quite a few records, but during a complicated form process, the user is ...
1
vote
1answer
24 views

SQL: SOS: MySQL indexes overloads disk

My server is down now, 'couse indexes of 84GB DB are overloads disc. Here is output of df-h: /dev/ploop58097p1 193G 187G 16M 100% / tmpfs 2,0G 0 2,0G 0% /lib/init/rw ...
0
votes
0answers
15 views

MySQL Case always executes the same [duplicate]

What I want to do is to set DATE_REACT a value when the first condition is satisfied, and a different value when the first condition is not satisfied. The problem is that the first condition is ...
0
votes
2answers
26 views

MySQL Case problem

I am trying to run a SQL code (I use MySQL). What I want to do is to set DATE_REACT a value when the first condition is satisfied, and a different value when the first condition is not satisfied. The ...
0
votes
2answers
22 views

Set of datetime versioned rows, how to build the most up to date row

I created this SQL fiddle with the sample data The sample data is this: -- -- Table structure for table `dogs` -- CREATE TABLE IF NOT EXISTS `dogs` ( `version_stamp` datetime NOT NULL, ...
0
votes
0answers
10 views

MySQL Replication problem with VIEWS and “Sub-Databases”

I've got three servers that should do a master-master replication. On server 1 i got "01_maindb" which holds the master tables. I replicate this table to the two other servers without problems. ...
0
votes
1answer
31 views

SQL “select” query for getting 0 instead of null?

In the database I have some value as null . So while fetching these null value from database it should be treated as 0 not as null. Note:- I don't want to be it done by code but from SQL query.
0
votes
0answers
17 views

MS Access using MYSQL database and error in SQL (memo, hyperlink OLE)

I have a SQL statement that works fine in MYSQL workbench but when used in Access it produces a "invalid Memo, OLE or Hyperlink Object in subquery 'custom_values.value'. SELECT ccr1.value, ...
1
vote
1answer
50 views

AND operator in ORDER BY clause

While debugging some code, I stumbled into an error pretty much like the following: SELECT * FROM person WHERE family_size > 3 ORDER BY birthday AND registered=0; The error is that the AND ...
0
votes
1answer
14 views

How to check mysql password change and other events logs

Recently someone change my phpmyadmin password and drop database I think it was sql injecting. Now I want to find information about this like when, how and who change my password Please tell me ...
0
votes
0answers
28 views

MySQL - Pivot-style (row -> column) results in subquery

SELECT j.departure, stopDepartures.* FROM journey j JOIN journey_day ON journey_day.journey = j.id JOIN service ON service.id = j.service JOIN pattern ON j.pattern = pattern.id JOIN ( SELECT ...
2
votes
2answers
61 views

Unexpected result from query based on old column value

I need to update a column and based on the old value, update a second column. After googling I came up with THIS (*nr 4) solution: copy the table to have the old value at hand. The table looks like ...
1
vote
1answer
39 views

How to find non utf8 data in mysql

Ok so I have a mysql database containing data that is input from various customers. The customers are told that their data should only be encoded as utf8 however I have become aware that this is ...
0
votes
1answer
41 views

SELECT count vs DELETE JOIN. Why/how are they different?

Can someone explain in what way these queries could be different and the results are not the same? > begin; Query OK, 0 rows affected (0.01 sec) >select count(*) from tableA a JOIN tableB ...
0
votes
0answers
25 views

SQL query to fetch results for multiple many to many relationship tables

We are developing a database for storing licensedetails of source code, archives, shareobjects, binary. We parse a detailed build and extract list of source files that make objects, list of objects ...
0
votes
0answers
29 views

MySQL hook and alter incoming INSERT queries?

We have an application running on a server which parses an xml data feed into SQL queries and executes them continually 24/7. There is a serious issue in the design of the queries and we need to ...
1
vote
2answers
36 views

Unable to SQL => Getting content of last 7 days

I thought I was good with SQL till I was told to get the content of all 30 days. I do have a column called "connect_time" which has date and time in the following format: 2014-08-28 11:11:42 All my ...
0
votes
1answer
84 views

Why isn't this index helping my InnoDB MySQL query?

I'm having trouble understanding why an index I have on one of my tables is doing nothing to help the performance of a JOIN, even when forcing the index. Here is the query: EXPLAIN SELECT * FROM ...
0
votes
0answers
27 views

Cant Normalize my dimensions and fact table, need help

I have a task at school that I can't get my head around. The task is to create some dimetables and create a facttable from those. The data I have chosen is from Export and Import cost for each year ...
0
votes
2answers
68 views

Querying MySQL, duration increases 10x fold after adding one more Join

I have a somewhat complicated query consisting of many joins on an issue tracker/project management database in MySQL. My issue is that my query was doing OK while I was in the process of building it ...
2
votes
1answer
54 views

Running a query on an improperly indexed, 600gb table

This is my first post on here and I'm really baffled by this. I have joined a team and somewhere in the past a horrific table was created which has been bloated to a point of 600+gb of data. ...
0
votes
1answer
27 views

column value is not increment after 10

I tried below 2 codes.... showing same error 1.SELECT columnname FROM tablename ORDER BY columnname DESC LIMIT 1 SELECT MAX(columnname ) AS max FROM tablename I am trying to increment value of ...
0
votes
2answers
53 views

MySQL: How to fetch nth level child menus of a parent menu

I have a menu which is parent of multiple menu items and each child menu has their own child menus. This pattern is continued till 5-6 vertical hierarchy level. I don't want to write a query which ...
1
vote
2answers
55 views

Getting root node for a given leafs IDs

I got the following tables: +-----------------+ | PRODUCTS | +-----------------+ | #product_id | | #company_id | +-----------------+ | | +---------------------+ ...
0
votes
2answers
37 views

How to rewrite subquery to return only 1 row

I need to somehow check if query result is NULL, MySQL returns error Subquery returns more than 1 row. How should I rewrite it in order to work correctly please? SELECT DISTINCT user.id, ...
2
votes
2answers
247 views

Get table name from union query?

This is my query SELECT Id, productName, Largeimagepath, Discount, Price, Image FROM tablename1 where Active =1 union SELECT Id, productName, Largeimagepath, Discount, Price, Image FROM tablename2 ...
1
vote
1answer
26 views

Are Blob Sizes Fixed?

I'm using sqlalchemy to store objects in a database. The kind of object I'm creating is unknown until run time. I could be storing something as simple as a string. I could be storing a jpg. I ...
0
votes
1answer
32 views

MySQL select data over time that matches pattern over several rows

We currently log data from our plants running remotely for diagnostic purposes on MySQL. I have been asked to come up with a typical running profile for several variables. For this, I would require ...
0
votes
1answer
65 views

Why does mysql give different result for this summations? [duplicate]

Can someone help understand the following behavior? mysql> select (1/3 + 1/3 + 1/3); +-------------------+ | (1/3 + 1/3 + 1/3) | +-------------------+ | 1.0000 | +-------------------+ ...
-1
votes
1answer
52 views

Select latest record for each ID

I have three tables that contains data as below: Users Id Name Other_Columns --------------------------- 1 John Blah 2 Ricky Blah 3 Stella Blah 4 Bob Blah Saldo Id ...
0
votes
0answers
37 views

mysql select latest per group using 2 different tables along with self join

I have a query SQL Fiddle which contains 2 tables tbl_data CREATE TABLE tbl_data ( id int(10) unsigned NOT NULL, type varchar(32) NOT NULL DEFAULT '', title varchar(255) NOT NULL DEFAULT ...
0
votes
1answer
50 views

How to generate a sequence in mysql

Consider this table in mysql create table numbers (number int); insert into numbers values (3), (2), (9); select * from numbers; +--------+ | number | +--------+ | 3 | | 2 | | 9 | ...