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

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3
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1answer
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MySQL - Create a function from another function

I want to create a function same like my old functions. When I create a table, I can use `AS to other table as follows: CREATE TABLE dummy2 AS SELECT * FROM dummy1; Can I do the same thing with ...
1
vote
1answer
149 views

a question in tables relations

Table A is linked to Table B , and Table B is linked to Table C using primary and foreign keys My questions: Should i link Table A to Table C too?? Or Table B can act as intermediate link between ...
3
votes
1answer
129 views

Help to create indexes to improve query performance and reduce report generation time

The database in SQL Server 2008 has these tables below - the main table being the Master: Master A_ID (PK) SYSSerialNumber Bootlog SequenceNumber FileName Cfg Unique(serialnumber,sequencenumber) ...
1
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2answers
350 views

Optimizing SSIS Packages

I have a SSIS package that loads data in an Access DB to tables on a SQL Server DB. Currently I double click the package and execute it. There are times when there is a lot of data to load. My ...
-2
votes
1answer
3k views

Which is the shortest way to find out if a float IS NULL or equals 0 in mysql [closed]

I want to type the least possible characters, to find out all columns in a table that are 0 or NULL In this example I explain it further: lets assume the table test CREATE TABLE IF NOT EXISTS ...
13
votes
2answers
7k views

Performance Tuning for Huge Table (SQL Server 2008 R2)

Background: I have a fact table in UAT Phase. Objective to load 5 yrs of data in Prod (expected size 400 Mn records). Currently it has only 2 years of data in Test. Table Features: No of ...
0
votes
1answer
149 views

MySQL query optimization

I'm quite new to big MySQL queries (I used to extract raw data from tables then manipulate them with PHP) so I'd like to know if my query below is too "heavy" or slow for some reason (it seems to be ...
0
votes
1answer
778 views

Average, between specific date/time, of the difference between current field and previous field

Im trying to calc the average, between a specific date/time, of the difference between the current field and the previous field. At present ive got a query which displays this but im unsure how i can ...
0
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3answers
626 views

Pivoting row contents to produce one dimensional result

I have a table with a varchar column containing pipe-delimited values For example: Row 1 Column 1 = a|b|e|gg|foo Row 2 Column 1 = oV|foo|do Row 3 Column 1 = boop How can I query this to return ...
0
votes
1answer
1k views

Massive update to Clob fields oracle 10g

I need to remove a string of characters from 2000+ clobs fields in oracle 10g. How would I do this in PL/SQL? For example, in table t1 there is a clob field called VBase that needs to have the ...
1
vote
1answer
969 views

How to create sql query results in columns from rows?

From the following tables: store(store_id, ...) {1 ..., 2 ...} two stores film(film_id, ...) inventory(inventory_id, film_id, store_id) rental(rental_id, rental_date, inventory_id, return_date, ...) ...
4
votes
3answers
32k views

Single sql query to select a record from parent table only if all it's records in child table has values

I've Table1 and Table2, Table1's PK is the FK of Table2. Now i need to perform a select from Table1 if and only if all the records in Table2 corresponding to a Table1 record has values (if any field ...
3
votes
1answer
11k views

Joining 3 tables using SQL Query?

I'm having problems joining three tables. It works well when I use the same query for joining two tables (after removing LEFT OUTER JOIN C ON B.No = C.No). However, it doesn't work when I use three ...
5
votes
1answer
540 views

SQL Server 2008 upgrade advisor tool

We upgraded to SQL Server 2008 from SQL Server 2000. But due to some legacy scripts/queries in our health care application, that run only in 2000, we had to run 2008 version on backwards compatibility ...
4
votes
1answer
14k views

Restore Backup Fails - File 'Db' cannot be restored to '{…}.mdf'. Use WITH MOVE to identify a valid location for the file

I am getting the following errors trying to do a restore using the restore command on a backup file I recieved from a customer. RESTORE DATABASE SFDB FROM DISK = N'C:\Backup\Backup.bak' Any ...
1
vote
1answer
89 views

Slave as a master in PostgreSQL [closed]

I have set up a hot standby in PostgreSQL 9.0 on Windows. I want that, at the time of fail-over, the slave should take over the role of master and start performing operations (both read and write) ...
1
vote
1answer
98 views

Tables of a huge database

When I work on a huge database, and after following normalization rules, I found that I have many tables for each part of my huge database. That makes me worry about the final number of tables, it ...
1
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1answer
70 views

Sanitizing a form's database input while retaining basic HTML markup

Is there a way to sanitize database input (say, for a comment form), which also allows for the end user to use basic HTML styling markup? As in, if a user wraps their text in <i>/<em> or ...
2
votes
1answer
502 views

UDF performance suddenly degraded

SQL Server 2008 R2 I know this is a common problem (eg: http://connect.microsoft.com/SQLServer/feedback/details/524983/user-defined-function-performance-is-unacceptable) - but ive only just learned ...
7
votes
2answers
2k views

PAGE compression in SQL Server effect on running queries

I am planning to apply PAGE compression to some of the big tables in my database (DW to be precise). These tables are fairly big with over 15 Billion rows. When I applied the compression in test ...
0
votes
2answers
3k views

Difference between chained and migrated rows

What is the difference between chained and migrated rows? Also what query should be used to display these rows? (I'm using Oracle 11gR2 database)
-1
votes
1answer
73 views

Can I make that connection?

If I have a column with data type varchar(max) in a table that contains a big piece of text, can I make a connection between a word or a sentence in that text with another word or a sentence in ...
2
votes
2answers
1k views

Why does my query run faster after I force full table scan?

I have a MERGE statement that took forever to execute the select as the table it is running from (SUB_DATA) is rather big (read 1.4 Tb, 700 million rows). My SELECT looks like this. SELECT ...
0
votes
1answer
351 views

Patients profiles database

I am making software for patients in hospitals. I want to make an option that if a doctor has prescribed a drug that interacts with another drug that the patient already uses, a warning will appear ...
3
votes
1answer
395 views

SQL query returns different results when index is dropped

In SQL Server 2000 SP4, I have a query SELECT <fields no aggregates> FROM PS_VED_VCH_TAO5 A ,PS_BUS_UNIT_TBL_AP B ,PS_RT_DFLT_VW C WHERE A.PROCESS_INSTANCE = 594170 ...
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votes
3answers
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Conversion failure varchar to int

When running this code: declare @SQL NVARCHAR(max); declare @intFlag INT; set @intFlag = 2; SET @SQL = ' SELECT * into [##tmp1] FROM servicesstats_0511_0412 s WHERE department=''ACC'' and ((SELECT ...
1
vote
1answer
335 views

postgresql pgadmin3 queryconnect attribute does not work

I'm using Fedora 17 and pgadmin3 to auto-connect to a postgresql database with one button click. Every time I want to run an SQL statement, I have to do 4 steps, (open pgadmin3), (connect to the ...
4
votes
1answer
9k views

query to find closest lesser date

I have a table with rates. each rate has an effective starting date. (the ending date of any rate is implied by the existence of a record with a newer effective starting date.) I also have a table ...
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3answers
347 views

Same query taking 0.2 sec in Oracle database but 4 mins in SQL Server

SELECT A.Field1 FROM Table1 A INNER JOIN Table1 B ON A.Field2 = B.Field2 AND A.Field3 = B.Field3 AND A.Field4 = B.Field4 AND B.Field1 = "string1" AND B.Field2 = "string2" AND A.Field5 = (SELECT ...
5
votes
2answers
768 views

How should I best design the tables and relationships, given the following rules?

In a Pawnshop business, customers pawn, sell or buy items. A contract which specifies the customers information, the items, and the terms and conditions is created whenever customers pawn, sell or buy ...
3
votes
2answers
265 views

Finding violations of the symmetry constraint

Suppose I have a table Friends with columns Friend1ID, Friend2ID. I chose to represent each friendship with two records, say (John, Jeff) and (Jeff, John). Thus, each pair of friends should show up ...
5
votes
3answers
2k views

Many-to-Too-Many Relationship

I'm working on a book database. And among others, I have the following two tables (a bit simplified for the question): tblBook: ID, Title tblPerson: ID, Name Note that the tblPerson table contains ...
0
votes
3answers
63 views

Query Optimizing Request

I am very sorry if this question is structured in not a very helpful manner or the question itself is not a very good one! I need to update a MSSQL table call component every 10 minutes based on ...
1
vote
1answer
202 views

Stored procedures and network congestion

When I went to an interview, the interviewer asked me "what are the benefits of stored procedures?" and I started answering but when I said "It reduces network congestion", he suddenly said "no, it ...
1
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2answers
103 views

Easy SQL, embedded select

I have a table of zip codes with latitudes / longitudes. Unfortunately it doesn't seem to have a few zip codes. I would like to try to approximate the latitude / longitude based on other zip codes ...
2
votes
1answer
7k views

Oracle error “too many values”, must be solved with nested SELECTs

I have hit upon a "too many values" error in Oracle, when working with some intricate nested SELECTs. A simplified description of my problem, on a toy problem describing the hierarchy in a company. ...
5
votes
1answer
2k views

Does UPDATE INDEXES work for local indexes?

I have two tables in Oracle 11.2. First is partitioned and has local index (non-prefixed): CREATE TABLE table1 (col1 INT, col2 INT) PARTITION BY LIST(col1) ( PARTITION p1 VALUES(1), PARTITION ...
0
votes
1answer
110 views

Logging of incorrect row in SQL Server Integration Services

I newbie to SQL Server Integration Services and I have a problem: Data loaded from file looks like this: 1 'a' 'b' 2 'a' 'b' 1 'c' 'd' And this rows would be loaded in table like this: CREATE ...
2
votes
1answer
695 views

Recovering from a stuck query

I have a big DELETE query (deleting 20M rows from a 600M row table with condition according to indexed column) that is stuck - running already for 17hrs. Because it's an InnoDB table, killing it will ...
3
votes
1answer
129 views

query discrepancies on very large postgres table

I have a fairly large table (25m entries) which stores tracking data, I am not a postgres admin by trade so this may be a simple problem. these two queries although similar are taking massively ...
1
vote
1answer
108 views

sqlite database: advanced SQL or redesign

I've been programming for several years, but I'm pretty new to SQL(ite). I'm designing a database for a sort of a bookkeeping program. What I've got so far: orders (o INTEGER PRIMARY KEY, ...
0
votes
1answer
2k views

Access query to select multiple records with matching field

I have a table with a list of people ([FirstName], [Surname], [Age]). Some of these people are in the same family. I'd like to return a list of people who have another family member in the table (same ...
5
votes
2answers
4k views

Is SELECT ROW_NUMBER() guaranteed to return results sorted by the generated row numbers?

E.g. consider the SQL query: SELECT A.[Name], ROW_NUMBER() OVER(ORDER BY A.[Name] ASC) FROM [FooTable] AS A Here I observe the results being returned sorted by A.[Name]. If I change the ...
2
votes
1answer
861 views

Populating an empty table using loops, conditionals, and accessing multiple tables

This question pertains to a MySQL database, although, in the end, this may be database neutral. I am trying to populate an empty table (let's call it NewTable) that I created. The data population is ...
9
votes
1answer
901 views

Is the optimisation fence behaviour of a CTE (WITH query) specified in the SQL:2008 standard? If so, where?

I see frequent references to WITH queries (common table expressions, or CTEs) acting as an optimisation fence, where the server isn't permitted to push filters down into the CTE queries, pull common ...
2
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3answers
2k views

Is there a way to tell SQLCMD not to output rows to text or a file?

I am testing the behavior of a SELECT statement that returns 170,000,000 rows using SQLCMD. My goal is to cut out the time spent receiving the result-set on the client end (the time the process shows ...
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votes
5answers
305 views

How much does an index need to narrow the results of a search in order to be useful?

How much does an index need to narrow the results of a search in order to be useful in speeding up queries? Some examples all across the spectrum: A column for storing true/false values obviously ...
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vote
2answers
141 views

How can I append a column to an inner SQL statement?

I have two tables that have the same structure except one has an additional column that should be auto-incremented. Sequence and trigger are defined. I want to copy all data from one table to ...
0
votes
1answer
406 views

how to pass url value to index [closed]

How to read the value from URL and compare with index that i have created in MYSQL table. I have a form where provide list of selection using drop down list and i pass the selected value to the next ...
1
vote
2answers
291 views

SQL query based on foreign key relationship

I have two tables, a Project and an Action: Project has the following fields: project_name Action has the following fields: action_name project status There is a one-to-many relationship ...