Structured Query Language (SQL). For questions about the language, not Microsoft SQL Server (tag sql-server).

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Merge 2 tables and fetch data one by one

I have two tables: product & offers. products has (prod_id, category_id, prod_name, brand, price, status) offers has (offer_id, prod_id, offer_type, discount_amt, validity) I want to display ...
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2answers
398 views

Do MySQL sub-queries essentially use as much overhead as separate queries?

If I have a query like this: SELECT name FROM ( SELECT * FROM `table` WHERE id IN (1,40,300) ORDER BY AnotherColumn ) From a bandwidth and overhead standpoint, is that the same thing as doing ...
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3answers
67k views

How to select distinct for one column and any in another column?

I need to query an SQL database to find all distinct values of one column and I need an arbitrary value from another column. For example, consider the following table with two columns, key and value: ...
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2answers
369 views

User-defined sort order for a query

I'm storing user preferences for sort order in a table: $queryHistory = "SELECT orderby,ascdesc FROM user WHERE UserID= ".$id; $resultHistory = doQuery($connection, $queryHistory); $numHistory = ...
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1answer
305 views

query optimization delete nested query [closed]

Can the following query be optimized ? DELETE FROM COLOR_TAGS WHERE COLOR_PROJECTID = $id AND NoteID IN( SELECT ID FROM note_note WHERE BibID=$bid AND isdel=0);
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2answers
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How do I use the IF…ELSE condition in a WHERE clause?

I'm attempting to use the IF...ELSE construct in my WHERE clause to selectively apply conditions to my SELECT. Should this work? CREATE OR REPLACE package body If_Else_Pack IS PROCEDURE Moving ...
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1answer
2k views

Mysql sub query returns more than 1 row

SELECT * FROM wp_posts WHERE ID IN ( (SELECT courses FROM wp_category WHERE CatID =401) OR (SELECT meta_value FROM wp_postmeta WHERE post_id IN (SELECT courses FROM wp_category WHERE CatID =401) ...
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2answers
47k views

Selecting two values from the same table but under different conditions

I want to grab a value from a table into two different columns for different values from the same table. Use this query as an example (notice how the select is on the same table aliased as 2 different ...
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1answer
92 views

linking databases for reporting

I am attempting to design a simple reporting feature for some financial market data. I have a few sets of data, and I am trying to figure out what will be the best way to organize the tables, in ...
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1answer
4k views

Why Is oracle ignoring my index?

This query is not too complex: select trunc(created_date, 'MONTH') as created_date, al.op_name, al.region, al.alarm_type, COUNT(1) as total_new, SUM( (SELECT ...
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3answers
2k views

Should order of column in where clause be same as the index order?

I was reading this use-the-index-luke.com which explains in detail how indexes work. One of the things this person has re-iterated that the order of indexes matter a lot and to make the query fast the ...
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1answer
1k views

Trying to Build TreeView Query in T-SQL

I have parent records in two tables, Table1 and Table2. Some records in Table3 are children of Table1, and some are children of Table2. I would like to build a query that I can use to populate a ...
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1answer
901 views

Retrieving queries when the hour of starting timestamp is less than the hour of ending timestamp

I have a CTE-based query in which I retrieve hourly intervals between two given timestamps. My query works as following: Getting start and end datetimes (let's say 07-13-2011 10:21:09 and 07-31-2011 ...
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2answers
571 views

What is the purpose of the USING parameter in SQL?

Working with some code on a standard MySQL database, and I came across this statement: SELECT * FROM foo LEFT JOIN bar USING ('bar_id') WHERE foo_id = 1 What's throwing me is: what is USING for, ...
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3answers
865 views

How to select data in a sub query only once?

I have the following query: SELECT ordno from orders where ordno NOT IN (SELECT ordno FROM invoices) There are about 25000 records in each table. I have indexed the ordno column. The query ...
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2answers
3k views

WHERE clause is not filtering on LESS THAN and GREATER THAN or BETWEEN

I am trying to select MTR values that are between the values of 0 and 4. What am I doing wrong? SELECT DATEDIFF(M, TheDate, TheOtherDate) AS MTR FROM MyTable WHERE MyID = 2074163 AND MTR >= 0 ...
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1answer
96 views

Count total where owner_user_id = some_value and deleted_by_owner = 0 or to_user_id = some_value and deleted_by_to = 0

I didn't know if this is possible using just a query or if I need some procedural logic on this one. I have this table: CREATE TABLE `default_messages_users` ( `id` int(11) NOT NULL ...
2
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1answer
113 views

Question about new behavior of current connection combobox in SQL Server 2012

I have a question about the new behavior of the database selection combobox in SQL Server 2012 (Press Ctrl + U to move your focus to it). It seems that, unlike in SQL Server 2008 R2, clicking in the ...
8
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1answer
2k views

Friends relations in MySQL

I'm developing a friendship relation in MySQL where friend relation is mutual. If A is friend of B, then B is friend of A. If one of the users end friendship then relation drops. I want to learn which ...
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2answers
2k views

EXECUTE sp_executesql

i have a problem with EXECUTE sp_executesql and stuck with it. my query is as follows DECLARE @TABLE_NAME VARCHAR(5)='#T' DECLARE @TABLE_ID INTEGER=0 DECLARE @QRY NVARCHAR(MAX) ='' ...
2
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1answer
648 views

Should I use left join to do my job in this scenario?

What I want to do is to find out the items which appeared more than once in this table: mysql> desc tables; +-----------------+---------------------+------+-----+---------+-------+ | Field ...
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1answer
984 views

Renaming the Data Sets in SSRS

What is the easier way to rename the Data Sets in completed SSRS report? I have created a report in BIDS 2008 and now for some reasons I have to rename the Data Set names, but it seems that renaming ...
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1answer
563 views

How do I query based on percentages of a subset of values?

I have a table with a column named Type that can have some set of values. For instance, A, B, C, D, etc. Behind the scenes this is mapped to an Enum. I need to query this table to get a percentage ...
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4answers
21k views

How to list all views in SQL in PostgreSQL?

How do I list all views for a database using an SQL command in PostgreSQL? I would like something similar to output of the psql \dv command, but preferably just a list of view names. e.g., SELECT ...
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3answers
3k views

Workarounds for setting default schema for domain group?

I am currently working on a project for a client, they have asked me to change the database from Oracle to SQL Server. So we migrated the database across to SQL Server 2008, when this was migrated ...
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1answer
18k views

“Operand type clash” with DATE column

I enter the following command into the SQL Server Management Studio insert into testtable ([product_name], [price], [expire_date], [expire_time]) values ('Teapot', 10.00, 23/12/2012, '12:35:00') ...
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4answers
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Shrink database is not shrinking as much as expected on a 1.5 TB database.

I'm working in an Enterprise system with a 1.5 terabyte database that is on a single filegroup, with the log in Simple Recovery Mode. Since we have many teams working on different projects in ...
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2answers
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PostgreSQL procedural languages - differences between PL/pgSQL and SQL

Can anybody please summarize the differences between: http://www.postgresql.org/docs/9.1/static/xfunc-sql.html and http://www.postgresql.org/docs/9.1/static/plpgsql.html ? Main points: ...
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2answers
372 views

Query for fetching records from SQLite database on Blackberry

I want to fetch data from SQLite database for Blackberry. There is one table with four columns: ID, FROM, TO, TIME I want to fetch record on the basis of FROM, and TO values. Where condition 1: ...
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2answers
559 views

Is it worth partitioning a Table by single value in Oracle?

Normally, if you have a column you frequently query a table by, you ought to stick an index on it. But is it worth also partitioning a table by this column, if all possible values are known in ...
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4answers
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How to check if a subquery has exactly one distinct result and a specified value concisely?

I found myself writing the following: select 'yes' where exists(select * from foo where val=1) and not exists(select * from foo where val<>1); and wondering if there is a more concise way ...
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Database starts always in recovery mode

Everytime I restart my server, the database is always in recovery mode, and it takes about 20 minutes for it to behave as normal. This always and only happens when I restart the server, so I have a ...
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1answer
83 views

Response On Database Failover

Let say, that I have principal server named P, and mirror server named M. I've got 7 databases that are in server P, and 7 mirror databases on server M. Whole engine works fine when we are talking ...
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1answer
3k views

How to design a table for storing news items?

I have a script that can get result from news websites and it will run every hour. The php script will get the title and content. The things I want to store in MySQL are: title content ...
4
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1answer
804 views

SQL Server 2008: use AVG() and an inner join

Here's what I have so far. I know this works, but I need to get the average of the pulse and depressionlevel instead of returning actual values for each row: SELECT Patients.LastName , ...
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1answer
1k views

Store SSRS Report export directly to database

As a requirement, I have to check for a certain condition on some data in the database, if the condition is true, then I have to create a pdf report and store it on a table. I have everything set up ...
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1answer
260 views

Selecting just one table from Oracle view [closed]

I am creating a view to ease my manual selecting because I only want to fetch data from DB where it is meeting certain criteria which are present in several tables, so it is containing a lot of joins. ...
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4answers
4k views

Is it possible to increase query performance on a narrow table with millions of rows?

I have a query that is currently taking an average of 2500ms to complete. My table is very narrow, but there are 44 million rows. What options do I have to improve performance, or is this as good as ...
3
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1answer
59 views

INDEX on a table where I'm only filtering on a row_number()

I've got the following table (scaled down to a MWE): Fiddle here. CREATE TABLE weekly ( yearnum int, weeknum int, location varchar2(5), weekly_count int, weekly_sum int); INSERT INTO weekly ...
4
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2answers
354 views

SQL Server Transaction Log Initial Data Load

What is the standard process when initially populating a database with 5GB+ to avoid a large transaction log? From my understanding the log file would jump to a large size after the initial load and ...
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0answers
152 views

hStmt/cursor error caused by faulty data?

Could a busy hStmt and invalid cursor errors be caused by faulty data? ODBC and the software that connects to the database is correct and working - i have ran a test with a clean database (that has ...
3
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1answer
884 views

Connecting to an SQL server instance without using square brackets to avoid backslash

In our company we have an old piece of software which was written by our previous I.T manager but was never finished. The program connects to SQL server but we want it to point to a newer SQL server ...
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2answers
8k views

How to GROUP_CONCAT DISTINCT values in a MySQL query that gets number of records and min/max values?

I'm running MySQL 5.0.88 (Coldfusion8) I have a product search which I'm querying number-of-results as well as min/max prices/rebates across the product table. I also want to include a string of ...
3
votes
3answers
448 views

selecting multiple instances of a record based on record lifespan over years

I have a table of items that have a origin date and a life span. I want to create a procedure that selects all of the items that will need to be replaced in a specific duration. I feel like there is a ...
2
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2answers
294 views

remote connection

Im trying to connect to a remote sql server using windows authenication. I'm using visual studio 2012 and going to a remote sql server 2012. I have already checked in sql studio that it is set up for ...
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2answers
1k views

Postgres query plan of a UDF invocation written in pgpsql

It's possible when using the pgadmin or plsql to get a hold of a query plan for a sql statement executed via a UDF (using EXPLAIN). So, how do I get a hold of the query plan for a particular ...
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3answers
1k views

Use MySQL to regularly do multi-way joins on 100+ GB tables?

Background: I’ve created a web application that I would like to be able to scale reasonably well. I know I'm not Google or Twitter, but my app uses a fairly large amount of data for each user and thus ...
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3answers
25k views

“lock request time out period exceeded” Error When Trying to See DB Hierarchies

I'm having problems with a database. I can run basic queries, albeit much slower than normal. When I attempt to view the hierarchy trees for tables, views, or procedures in SSMS Object Explorer, I ...
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0answers
2k views

Can't Restore DB Because of Active Connections [closed]

I have a DB I would like to restore. There are other active connections on the DB. I tried using sp_who2 to find those connections and manually kill them. Unfortunately, this did not solve the ...
2
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1answer
473 views

Cross Apply without a function

I would like to run a query very similar to this on one of my production databases: -- Setup the table (Already there in my real scenario) create table dbo.MyTable(MyValue int, MyGroup varchar(5)) ...