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

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3answers
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find all numbers that appear at least three times consecutively

This is a question from leetcode online judge I tried this SELECT Num FROM Logs GROUP BY Num HAVING COUNT (Num) >1 but got runtime error!! Anyhelp would be appreciated
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1answer
95 views

Inserting into related tables

I have a database setup with the following schema: CREATE TABLE siteInfo ( siteID SERIAL NOT NULL, siteName TEXT NOT NULL, siteHost TEXT ...
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1answer
2k views

Alter table Statement Failed -Msg 207, Level 16, State 1

I wrote a script to add a column in a table and on successful execution update its values. I know it’s just a simple script but what is wrong with the ‘IF NOT EXISTS’ statement why script between ...
2
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3answers
2k views

Return total number of rows and selected (aggregated) data

I have a function which is selecting some data from a table. I would like to return the selected data and the total number of rows in that table. How can I do that or how can I get the same result in ...
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2answers
2k views

How to insert values in junction table for many to many relationships?

I have three tables in database: trips(trip_id(pk), trip_name(unique), user_id(fk)) places(place_id(pk), place_name(unique)) trips_places_asc(trip_id(fk), place_id(fk)) Since many trips can ...
2
votes
1answer
515 views

Difference data between adjacent rows

I have a table (called Visits) with ReqTime DATETIME NOT NULL column AND Duration INT UNSIGNED column. Duration should be set to the difference of ReqTime for two adjacent rows. But Duration is not ...
2
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2answers
176 views

Database events that will cause deletion of index

In SQL server if we try to change a data type of a column having index ,then it deletes the indexes associated with that column and changes the data type . I was not aware of it and was faced problem ...
2
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2answers
7k views

How do I include nulls during comparisons in SQL Server?

So basically in SQL Server a NULL means there is no value and thus can't be compared which returns some unexpected results. For example, the following query doesn't return rows where value IS NULL ...
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4answers
891 views

How to join the latest previous record with SQL

The original question was posted on stackoverflow. I think this site could be more focused on db related topic. I have a table whose schema is like this: CREATE TABLE product_shipping( ...
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1answer
4k views

Very slow simple PostgreSQL query on RDS

I seem to be getting very slow queries on a medium sized RDS box (db.m3.medium, 3.7gb ram). This is across a table of 4,152,928 rows.. select sum(some_field) c from pages where pages.some_id=123 and ...
2
votes
4answers
8k views

Is it ok to change from full recovery to simple recovery in Sql Server

I have an old database - a users membership/role that was setup automatically by an ASP.Net 2 application years ago: The Sql Server version currently running is: Sql Server 10.5.1617 The users ...
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0answers
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Modulus calculation for compound primary keys in MySQL Cluster (and other sharded databases)

In MySQL Cluster, and generally in sharded databases, how is a compound primary key's modulus calculated? Say, for example, there are two tables that have primary keys like so: CREATE TABLE Orders ...
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2answers
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Design of an application log database

We are generating logs like following example(this is a table no actual pipes): 2014-06-10 09:00:03.457 | Channel1 | Operation3 | Function15 | 15ms 2014-06-10 09:00:08.245 | Channel2 | Operation5 | ...
2
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2answers
412 views

Count where previous record exists in either of two tables

I'm trying to COUNT records on one table where both the counted records and their "previous" records exist either in the same table or on another. The table that I'm sampling has a composite PRIMARY ...
2
votes
1answer
472 views

How to speed up looped INSERT INTO statements?

I currently use the following statement, for 10,000 rows it takes about 150 seconds. I tried removing the index on the target table, but this didn't help. Running the loop without the INSERT INTO ...
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2answers
7k views

Possibly tempdb out of space or a system table is inconsistent

While running DBCC CHECKDB I got this error Msg 8921, Level 16, State 1, Line 1 Check terminated. A failure was detected while collecting facts. Possibly tempdb out of space or a system ...
2
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2answers
181 views

How to merge column in mysql depending on match

I have one table which looks like this in mysql column1 column2 name column3 data 1 1 foo 1 1.5 1 1 foo 2 2.5 1 1 foo 3 ...
2
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2answers
70 views

Table Transformation with SQL?

I got a set of tables which have been imported into a database by transforming them like shown in the following picture: Now it is necessary to get the former tables back. Unfortunately the guy who ...
2
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2answers
374 views

UPDATE table with another table data

I want to update the table car_check field fencing.(total 40 rows).I also use postgis function. I think it's a little difficult.Any suggestions? The code is the first carid example. UPDATE car_check ...
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2answers
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Order of returned record with IN statement postgres

I know that the order of returned records is not guaranteed with the IN statement for Pstgres. For example if I do this: SELECT "users"."id" FROM "users" WHERE "users"."id" IN (13589, 16674, 13588) ...
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2answers
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Optimizing removal of duplicate rows from recursive CTE query

I need to write a recursive SQL query to fetch multiple projects together with their lineage from the following table: CREATE TABLE #Project ( Name VARCHAR(10), ParentName VARCHAR(10) ) INSERT INTO ...
2
votes
1answer
72 views

How to go about modeling the main object of relationship?

I'm using MySQL and MyISAM tables. I have a bunch of objects that I want to group together 1 object belongs to 1 and only 1 group 1 group can have many objects 1 group has 1 required main object ...
2
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1answer
3k views

Query taking non-consistent time to execute [closed]

I have a query which takes large time to execute sometimes.When i checked the speed it was taking 15 seconds.But actually it should run faster than that.When i again checked the query it again ...
2
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2answers
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How to join multiple tables (SQL) to find the difference between an order and shipped quantities?

I have a collection of orders that were submitted to an internal ERP, which were processed and partially shipped. The table hierarchy is as follows: Order table contains OrderReference(PO), OrderID ...
2
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1answer
271 views

Relative cost of two similar queries involving XML columns

I have two queries as shown below which do the same thing. Here xmlcolumn is a column with datatype XML. I use these queries to search for a string anywhere in the XML column. I checked the execution ...
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2answers
12k views

Dynamic Oracle Pivot_In_Clause

I'm kinda stuck. I want to do a user-role-relationship pivot table and my query so far looks like this: WITH PIVOT_DATA AS ( SELECT * FROM ( SELECT USERNAME, GRANTED_ROLE ...
2
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1answer
167 views

Is it ok to let users add new columns and tables to your database?

I'm basically making a database of databases. An administrative User can go in and hit "Create Database" (which is basically a table) and set up the column types and how many columns. Other users can ...
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1answer
1k views

Reorganize full text catalog is offline or online?

I need to schedule a Full Text Search Maintenance and I was reading this link: http://msdn.microsoft.com/en-us/library/ms176095.aspx. Reading this documentation I am supposing that I need to ...
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3answers
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Is transaction log lost after backup on SQL Server?

I have database that has regular nightly backup (full recovery, full backup). I noticed some irregularities in data and wanted to check out transaction log to see what happened. I restored earlier ...
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4answers
2k views

search for something in the first 1000 records in the table

If I do the following MySQL query select * from table where name Like '%john%' limit 5; that mean the query will search all the mysql database table and return only the top 5 results that match the ...
2
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1answer
4k views

Select the top 5 records and the specific column from each table in the same database

I have 50+ tables in a database. I don't want to use the following SQL on each table in a database. select top 10 * from {table_name} So, is it possible to display the first 10 records PLUS only ...
2
votes
1answer
938 views

SQL INSERT Query takes 2 seconds and sometimes much longer to execute

I know the question's title is bad, But I have an hard time figure it out my self... sometimes this query runs in 2-3 seconds and sometimes it's takes even 30 seconds I have a table named ...
2
votes
2answers
1k views

How to GROUP_CONCAT between given rows?

I have a table as id diary 1 breakfast 2 walk 3 start 4 office works 5 office projects 6 end 7 taxi 8 start 9 preparing for meeting 10 doing the meeting 11 end 12 night I want ...
2
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1answer
5k views

How do I completely remove MySQL from a 64-bit windows 7 machine?

I'm new to MySQL and struggling to find a version and workbench which is stable on my 64 bit Windows 7 machine. I've decided to attempt to completely remove MySQL from my machine and to restart the ...
2
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3answers
498 views

MySQL Query - How to get most recent demographics?

I have a table that has duplicated cardnbr's. I need to pull out demographics that are the most recently used by the customer. I have a date field (lastvisit) that shows their most recently used card. ...
2
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0answers
211 views

Get all comment.message, status.message, users.* and profiles.* where users.user_id exists in friend.friend_id or friend.user_id

I need some help building this query because it's a bit complicated at least for me. I need to get all comment.message, status.message, users.* and profiles.* where users.user_id exists in ...
2
votes
1answer
803 views

Change in datatype?

I have a table on which rows are inserted on hourly basis. The row contains id, installation, product_id and hit_allowed. all of them were mediumint in the beginning. but few days back id reached it ...
2
votes
1answer
310 views

Flat query to Column structure

I am trying to structure a query for a calendar view. I want each row to return the details for a person and what they are doing for 7 days (split into AM and PM) So the result set might look like ...
2
votes
3answers
324 views

How to get all non deleted messages from one user

I have two tables one for messages called default_messages and the other for recipients called default_recipient. This is how SQL for those table looks like: CREATE TABLE IF NOT EXISTS ...
2
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1answer
189 views

SELECT for values in a table

I have this table structure: id1 id2 1 2 1 3 2 1 2 4 id1 and id2 are not unique as you can see in the values. I need to retrieve those values that exists in the two columns ...
2
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3answers
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performance of multi field primary key or 'contrived' 'semi artificial' key

This is not a question regarding the benefits or otherwise of using an artificial auto increment key in any given table against using a multi-field 'primary key'. That discussion (or argument) can ...
2
votes
5answers
20k views

Retrieving row count without using Count function

I wrote a query below which shoots me a syntax error why would it do so, SELECT MAX('Row') FROM (SELECT ROW_NUMBER() OVER(ORDER BY ID DESC) 'Row' FROM USERS) Error Desc: Incorrect syntax near ...
2
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2answers
1k views

How can can I get object definitions stripped of all comments?

When I want to know if a stored procedure or views references a given name (table, view or column), I need a version of the object definition stripped of all comments. Is this possible by a SQL ...
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vote
1answer
37 views

Return Bit Value based on previous records by Category

How would I return TRUE or FALSE if four of the last six records failed for a given MAKEID? So there has to be 4 failures (or FALSE records) in the last six MAKEID FAILURES CREATEDATE 101 ...
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5answers
145 views

Should I have a column for every data type or 1 column that stores everything

I have a database table that currently looks like this: PageField -Id (Int, PK) -FieldType (String) Can be Text, Decimal, Integer or Bit -Value (This stores the value regardless of the FieldType, so ...
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2answers
53 views

Select column to be inserted based on input column value

Assume the following two tables (and ignore the quality of the database design): Table 1 has columns id, sequence_number, value: it contains many rows. Table 2 has columns id, seq1, seq2, seq3, ...
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3answers
155 views

Best DB structure for large CSVs?

I have previously posted on stackoverflow, however, I have been directed here. I'm getting to the stage where I need to analyse lots of flat CSVs: Read-in around 500GB of CSVs (e.g. daily data ...
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1answer
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Constrain/limit certain records in sql table definitions

Let's say I have posts on which users can leave a comment. And I want to limit the amount of comments to a certain post to 10, is it possible to add such constraint/restriction to the table? My guess ...
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0answers
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SQL Server 2012 memory issue [closed]

I am having performance issues on a Windows 2012 Server running SQL 2012. When I run the DBCC MEMORYSTATUS command I receive the following. Process/System Counts Value Available Physical Memory ...
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2answers
155 views

Use array expression from subquery in ANY() condition

I have a relatively complicated query with a subquery fetching an array like so: ... ARRAY(SELECT category_id FROM category_schedule_con con WHERE s.id = con.schedule_id ORDER BY category_id) ...