DO NOT USE this for questions targeting Microsoft SQL Server, use the tag sql-server instead. "SQL" is an acronym for "Structured Query Language", it is used in relational database management systems (RDBMS) to query, update, delete, and insert data as well as modify the structure of the database. ...

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2
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2answers
6k views

Why can't we specify group functions in Oracle in the where clause?

SQL> desc tab1 Name Null? Type ----------------------------------------- -------- ---------------------------- ID ...
4
votes
4answers
4k views

Storing arrays of integers in database (for efficient select)

I am creating a database that will store 100.000 (and probably more in the future) users. While this obviously happens in a table with 1 row per user, every user can (and will) store hundreds of ...
1
vote
1answer
158 views

Duplicate record problem

create table #Personel ( Ad varchar(100) ) create table #Masa ( MasaAdi varchar(100) ) insert into #Personel values('deneme1') insert into #Personel values('deneme2') insert into #Personel ...
3
votes
2answers
868 views

A query submitted from different applications has differing DOP

I have a query which selects from multiple views and is fairly I/O heavy. If I execute this query using Management Studio it uses parallelism across most of the 16 CPUs and completes in under 10 ...
1
vote
1answer
783 views

Cartesian Product SQL / Inserts with multiple Values Clauses

I want to create cartesian product sql query.But,I'm getting the error.Where I wrong? alter table #Personel ( Ad varchar(100) ) alter table #Masa ( MasaAdi varchar(100) ) insert into #Personel ...
0
votes
1answer
340 views

Date Format in Sql Server

I am importing data from another sources, which has multiple columns but I am facing problem in date column like I have multiple format in this column like: dd/mm/yyyy mm/dd/yyyy mmm-yyyy Can you ...
1
vote
1answer
156 views

Is it require to fill all tables inside of the database?

Now,I created upper that table and in order to test I will give 3 textboxes values as below. SqlCommand cmd = new SqlCommand ("Insert Into dbo.PrnInf(PrnName, PrnSurName, PrnEgn ) Values ...
1
vote
2answers
1k views

null check and string concatenation

Can I do better than this query? select func_returns_str('key1') || nvl2( func_returns_str('key2'), ',' || func_returns_str('key2'), null) from dual; I ...
1
vote
1answer
804 views

Is it possible to write an SQL query that automatically reconciles/“transactionalizes” payments and charges

I'm still working on the project mentioned here (http://dba.stackexchange.com/questions/2428/how-do-i-properly-design-a-many-to-many-charges-payments-accounting-system). The system is to give the ...
4
votes
1answer
672 views

Speeding SQL queries for a large(?) WordPress database?

I am using a WordPress plugin called feedwordpress in order to run a planet like website (it takes content from other websites, with their permission) on WordPress (See it here). The plugin is great ...
11
votes
2answers
5k views

Reasons for occasionally slow queries?

We are running MySQL 5.1 on Windows Server 2008 R2. We have been doing some diagnostics on our database of late and have found some disturbing artifacts which we can't explain. We added some code to ...
5
votes
2answers
611 views

SQL Server configuration / specification recommendations and advice!

I am about to deploy a new server at work as follows: Dell T610 2 x Xeon 2.53 Quad core 24 GB RAM 1 x Perc H700 RAID controller with 1GB Non Volatile memory 8 x 300GB 15k SAS Hard drives I am looking ...
24
votes
3answers
45k views

How do I use currval() in PostgreSQL to get the last inserted id?

I have a table: CREATE TABLE names (id serial, name varchar(20)) I want the "last inserted id" from that table, without using RETURNING id on insert. There seem to be a function CURRVAL(), but I ...
8
votes
2answers
10k views

How can I specify the position for a new column in PostgreSQL?

If I have a table with the columns: id | name | created_date and would like to add a column, I use: alter table my_table add column email varchar(255) Then the column is added after the ...
2
votes
1answer
594 views

SQL Return Count of Answers with 0's for Choices from another table

My question went dead after one unhelpful answer on SO here I need this to be optimized because it will be called often. It is going into a stored procedure. I am given @slide (tblILDSlide.id) and ...
3
votes
2answers
2k views

PostgreSQL: count datasets / lines containing NULL values

I'm looking for a easy function to get the number of datasets (of any table) containing NULL values. It's not important how many columns are involved. For example: CREATE TABLE tab1 ( id INTEGER ...
6
votes
2answers
1k views

MySQL connection doesn't work anymore

I had two MySQL servers running (127.0.0.1:3306 and 127.0.0.1:3307). Now I get this strange error: mysql_connect(): Lost connection to MySQL server at 'reading initial communication packet' I can ...
5
votes
4answers
9k views

Optimising join on large table

I am trying to coax some more performance out of a query that is accessing a table with ~250-million records. From my reading of the actual (not estimated) execution plan, the first bottleneck is a ...
4
votes
1answer
1k views

Strange SQL Server 2008 behavior while using XLOCK and ROWLOCK

I wrote this script without COMMIT in a new Query window (Query1): BEGIN TRAN SELECT [RegionID], [RegionDescription] FROM [Northwind].[dbo].[Region] WITH(XLOCK,ROWLOCK) WHERE RegionID = 3 and in ...
4
votes
2answers
2k views

SELECT statement with an explicit list of columns and then an asterisk (*)

SQL Server allows to use SELECT statements similar to: SELECT FirstName, LastName, City, * FROM dbo.Customers When I try to execute such a query on Oracle database, I get the following error: ...
6
votes
2answers
1k views

Using totals on aggregates to improve performance

I have two tables: details and totals of these details. Details (Slow solution): select OrderId = r.OrderId , TotalQty = SUM(r.Quantity) , ...
13
votes
5answers
130k views

How to update a table from a another table

I have one table A has column (id, field_1,field_2), and another table B has column (id,field_2) Now I want to merge table B to A, that means i want to update field_2 in table A to value of table B. ...
5
votes
3answers
1k views

What could be the reason for disallowing a sub query in the values clause?

For example SQL> create table dates(d date); Table created. SQL> insert into dates select sysdate from dual; 1 row created. SQL> select * from dates; D --------- 28-MAY-11 SQL> ...
7
votes
5answers
19k views

In Oracle how do I save a sequence.nextval in a variable to be reused in multiple inserts?

I'm writing a script to populate some tables with data for testing. I would like to write something like the following but I don't know how to do it (I'm Oracle 11g) SET ENABLED_USER_ID = ...
46
votes
1answer
116k views

How to insert values into a table from a select query in PostgreSQL?

I have a table items (item_id serial, name varchar(10), item_group int) and a table items_ver (id serial, item_id int, name varchar(10), item_group int). Now I want to insert a row into items_ver ...
12
votes
1answer
3k views

Patterns for setting up sharding for SQL Server 2008 R2, in order to handle large datasets?

I want to handle a large dataset (> 1 billion rows) in SQL Server 2008 R2. I heard that if you set up "sharding" or "horizontal partitioning", it makes it quicker to handle large datasets as it breaks ...
3
votes
1answer
334 views

Badly performing query plan after adding ORDER BY to Full Text CONTAINS search

The following query is proving beyond my abilities to fix - hope someone can help. SELECT top 100 Id, Name, InsertDate FROM Foo WHERE CONTAINS(FooText, '"test*" and "hello*" and "goodbye*"') ORDER BY ...
2
votes
1answer
283 views

MySQL Update: why would rows matched change based on the set clause?

I ran an update query joining across a huge number of tables that updated one field, and it matched 29k some-odd rows. Running the same query with only an addition in the Set clause increased the ...
2
votes
2answers
377 views

update stored proc ony fields that are passed to the proc and leaving others alone

i have a stored proc that does a simple update (see below). i want to update only fields passed and not the ones that are null. that is to say if i dont get a parm value for somethign i dont want ...
4
votes
3answers
376 views

Help with complicated MySQL query

I asked an earlier question about modeling MySQL data modeling help. The recommendation was the diagram labeled Multiple Tables for Role and Sponsor. Now I'm trying to write the queries and ...
5
votes
1answer
486 views

Dealing with temp tables when I have not control over db variables

I have no control over things like tmp_table_size and max_heap_table_size, and so as our tables grow the time taken by queries requiring temp tables is growing geometrically. I am wondering if there ...
1
vote
1answer
117 views

Are there situations where queries are formed geometrically?

The topic came up in this other question. We were discussing sign value on a primary key having any significance. If there are good times to use geometry in building queries the sign value could be ...
1
vote
1answer
1k views

How can I alter the type of a money-column to decimal in PostgreSQL?

I have a table in PostgreSQL where one column "vat" has type money but I would like to alter it to decimal instead. How can I do it? I tried with: alter table my_table alter column vat type ...
8
votes
4answers
2k views

How can I optimize this MySQL query further?

I have a query that is taking a particularly long time to run (15+ seconds) and it is only getting worse with time as my dataset grows. I have optimized this in the past, and have added indices, ...
1
vote
3answers
376 views

Insert to particular location in Oracle DB table?

Suppose I have a table containing the following data: Name | Things ------------- Foo | 5 Bar | 3 Baz | 8 If I want to insert a row, so that the final state of the table is: Name | Things ...
15
votes
5answers
28k views

How can I use a default value in a Select query in PostgreSQL?

I would like to use a default value for a column that should be used if no rows is returned. Is that possible in PostgreSQL? How can I do it? Or is there any other way I can solve this? E.g. ...
21
votes
4answers
7k views

Why does MySQL not have hash indices on MyISAM or InnoDB?

I have an application that will only select on equality, and I figure I should use a hash index over a btree index. Much to my dismay, hash indices are not supported on MyISAM or InnoDB. What's up ...
5
votes
2answers
11k views

Relational Design - Multiple tables into one foreign key column?

Take a table that tracks meat purchases. It has a "meat_id" foreign key column to indicate what type of meat the purchase was. But, the different types of meat are unique in some way (such as USDA ...
15
votes
3answers
934 views

Alternatives to concatenating strings or going procedural to prevent SQL query code repetition?

Disclaimer: Please bear with me as someone who only uses databases a tiny fraction of his work time. (Most of the time I do C++ programming in my job, but every odd month I need to search/fix/add ...
8
votes
2answers
975 views

LNNVL Justification

LNNVL is an oracle built in function that returns TRUE for conditions evaluating to FALSE or UNKNOWN, and returns FALSE for conditions evaluating to TRUE. My question is what would be the benefit of ...
8
votes
2answers
12k views

How do I show the binlog_format on a MySQL server?

How do I show the binlog_format on a MySQL server? And if I dont like it how do I set it to XX permanently? Where XX is STATEMENT, ROW or MIXED.
1
vote
3answers
129 views

Can I automate the “on” statement from MySQL queries?

Background In the process of QA/QC, I am writing lots of queries with multiple joins. I am using MySQL. I would like to know how (if) I can simplify join statements, e.g. by setting default fields ...
14
votes
4answers
42k views

How to add sysadmin to user in SQL Server 2008 when no sysadmin accounts exist

I have a SQL server 2008 instance running. Unfortunately during testing I deselected the sysadmin rights for my login and now can't readd it (because I don't have sysadmin rights). There are no other ...
10
votes
5answers
5k views

Group By hour over large dataset

Using MS SQL 2008 I am selecting an averaged field from 2.5 million records. Each record represents one second. MyField is an hourly average of those 1 second records. Of course the server CPU hits ...
7
votes
2answers
2k views

How to effectively query and aggregate a normalized SQL db?

In relation to Most efficient way to return multiple aggregates in a single stored proc? I have an email type application and want to select all the messages (inbox) for a user. The problem is that I ...
4
votes
4answers
352 views

Do cross-joins get optimised by the client library?

Note This is deliberately database agnostic, I'm interested in how different implementations, er, differ. I came across Joins are for lazy people on SO, and it's made me question an assumption I'd ...
3
votes
2answers
4k views

Stored procedure parameters using tsql functions?

Environment sql server 2005 sp3 I have a stored proc that takes an INT as input. I want to CAST a CHAR to an INT during the call to the stored proc. it seems I cannot do that. I get a syntax error ...
47
votes
4answers
16k views

What is the difference between select count(*) and select count(any_non_null_column)?

I seem to remember that (on Oracle) there is a difference between uttering select count(*) from any_table and select count(any_non_null_column) from any_table. What are the differences between these ...
2
votes
2answers
3k views

Sp_helptext Error

I am using sp_helptext to list some stored procs instead of going through the ui. I am having a problem with the naming convention we have chosen to adopt. I have a stored proc nameed [Test.FooBar]. ...
12
votes
4answers
1k views

Creating centralized DBA database

We have 200+ servers and I am thinking about creating a centralized DBA database where it logs backup, errors, space jobs and generate reports on SSRS. I am not sure where to start and I would highly ...