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

learn more… | top users | synonyms (2)

1
vote
4answers
107 views

Find the winner of each stage

I am learning SQL, and I am trying to get a job. I have the following table in MS SQL Server 2014: The table is called Game with the following fields: Name, Stage #, Score. My goal is to write the ...
1
vote
3answers
218 views

Full database backup

I'm using third party tool for making schedule database backups. I need to make one additional full backup. Should it be affected on the scheduled backups? If yes, is there any solution?
1
vote
3answers
813 views

Compare two tables amount with respect to priortization of FundType

I have two tables one is PaymentDetail and another is Ledger Here i want to prioritize paymodetype in manner that cash should be considered first for R,A and then I FundType, then Credit Card, ...
1
vote
5answers
1k views

Frequent or Infrequent Commit

I'm trying to run an update query but still taking to long I have a commit in it. Is it better to set the commit to a higher value (5000) or lower (1)? I have to update 15 million records in a table ...
1
vote
5answers
161 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 ...
1
vote
3answers
75 views

Why is Convert being used in this statement and how does it differ from CAST?

This is a piece of code on MSDN page for OVER clause: USE AdventureWorks2012; GO SELECT BusinessEntityID, TerritoryID ,DATEPART(yy,ModifiedDate) AS SalesYear ,CONVERT(varchar(20),SalesYTD,1) AS ...
1
vote
6answers
266 views

Database with only text fields

I started working on an existing SQL Server Database System in which most of the fields are stored as text. Except some IDs all fields are varchar (phone numbers, zip codes, Dates, addresses, monetary ...
1
vote
3answers
648 views

Should I split a single table with an AUTO_INCREMENT PRIMARY KEY into two tables that can be joined on that PRIMARY KEY?

I have a table that has 46 fields with an AUTO_INCREMENT PRIMARY KEY. It's hard to look at a table that has this many columns, so I frequently use a SELECT statement to look at 34 of the fields that ...
1
vote
4answers
323 views

Is there a DBMS that allows the “= NULL” syntax?

Inspired by a StackOverflow question (Why doesn't SQL support "= null" instead of "is null"?). Is there a DBMS that actually supports the = NULL syntax?
1
vote
3answers
276 views

Remove duplicate values from query result

I am using Postgres 9.3.9. I have 2 tables : f_agent : CREATE TABLE f_agent ( f_agent__id bigserial NOT NULL, f_agent__total_users integer NOT NULL, f_agent__dim_time_id integer NOT NULL, ...
1
vote
2answers
117k views

Select which has max date or latest date

Here are two tables. SCHOOL_STAFF SCHOOL_CODE + STAFF_TYPE_NAME + LAST_UPDATE_DATE_TIME + PERSON_ID ================================================================= ABE Principal ...
1
vote
2answers
211 views

Can this SQL be made more efficient and combined into one select?

I have the 4 SQL queries below that I combine into one result set at the end. I am guessing that since I am operating on the same tables in each of the SQL sections, there is a cool way to get my ...
1
vote
3answers
213 views

Replication taking too much time between requests

We are using transactional replication in SQL Server 2014 with one master (publisher), 1 distributor (dedicated server), and 3 slaves (subscribers). All writes are made to master and reading is done ...
1
vote
4answers
435 views

Database/Storage engine suggestion for a project involving heavy inserts?

I am looking into a project which involves large number of inserts daily.I will have a list of user's (for example a user set of 500k ) , for which I need to monitor daily certain activities ...
1
vote
3answers
831 views

Proper use of database functions for business logic

I have a database in postgres with 147 tables; these tables contain data generated by functions that have most of the logic of the system, for example how to build an accounting entry. These ...
1
vote
1answer
10k views

How to check for null in column? and use other column instead?

How would I write a query that involves the following check: if colA is null then colB = colB1 + colB2 if colA is not null then colB = colA
1
vote
1answer
7k views

How can I get all orphan records in a single query?

I just noticed few tables that has orphan records (foreign keys) that no longer point to any primary key. How can I query the tables to get a list of all such rows? When these parent records got ...
1
vote
5answers
590 views

What is the advantage of partition Date field into individual Year(int), Month(int), Day(int), Time(time) columns? [closed]

What is the advantage of partition Date field into individual Year(int), Month(int), Day(int), Time(time) columns? My manager said this is well known practice and query performance is good. Is this ...
1
vote
2answers
107 views

Saving a SQL Server database to a file and opening it on another server under any database name

I am trying to find an efficient way of being able to physically save and open a SQL Server database like how it's done with Access. I would like to be able to save my entire database into a file ...
1
vote
2answers
557 views

Query Performance Tuning on a huge table

I have the following table Transactions. The table looks like this: CREATE TABLE [dbo].[Transactions]( [TransactionID] [bigint] IDENTITY(1,10) NOT NULL, [PlayerID] [bigint] NOT NULL, ...
1
vote
3answers
1k views

Usefulness of a multi-attribute index

If an index has more than one attribute in it, is there any speed gained in a select statement whose where clause uses one of the attributes in the index? For example, take a table T with an index on ...
1
vote
3answers
78 views

SQL Server - Index Including PK

Lets assume we have a table as follows: PK -- nonclustered primary key Col1 -- unique clustered Col2 Col3 Is this index: nonclustered index on (Col2, Col3) any different from this index: ...
1
vote
3answers
135 views

When to use DISTINCT [on hold]

When is it good to use SELECT DISTINCT .. and when not? Basically whenever I see DISTINCT keyword I start to get cautious as most of the cases it is ends up finding that actual query has some ...
1
vote
2answers
111 views

Converting rows to columns

I have data like following: created_at | status ---------------------+------------- 2016-04-05 1:27:15 | info 2016-04-05 3:27:15 | info 2016-04-05 5:27:15 | warn 2016-04-05 ...
1
vote
1answer
452 views

Is introducing a where condition into the join clause bad practice

In the query below, the condition and r.master_seq=206 is used on the on clause as a join condition. In the programme code, the value for r.master_seq is set by a parameter. My concern is ...
1
vote
3answers
469 views

How to decrease RAM usage of SQL Server 2012 without restarting Service

Is there a way of decreasing RAM usage of SQL Server 2012 without restarting it? Setting up MAX Memory usage is not an option as it's quickly building up to limit I have set and then app based on ...
1
vote
1answer
385 views

Can we use TDE as an anti-injection technique

TDE prevent unauthorized access to the data by restoring the files to another server, because it requires the original encryption certificate and master key. If i applied a table level encryption ...
1
vote
3answers
712 views

How to determine if SQL Server will not execute parts of the script in parallel?

Are there any general rules or maybe easy way to tell if SQL script will execute in batches instead of "all at once"? USE UserDB; GO DBCC SHRINKFILE (DataFile1, 5); GO DBCC SHRINKFILE (DataFile2, ...
1
vote
1answer
970 views

Multiple like conditions for same column?

How do I write a query for a Oracle database when I have several "like" values for the same column (in my example data "name")? My example data for table "address": name like "John" name like ...
1
vote
3answers
6k views

How do I use SSMS to compare Database 1 Table 1 against Database 2 Table 1?

I have two database - Database1 and Database2. Both database contain a table that have similar structure as follows: ...
1
vote
2answers
107 views

How does an alter work?

I have a table with a lot of records (more than 15M) and i am executing an alter query to add 2 columns to the table. the query is taking around 1hr to finish executing. So my question is: How does an ...
1
vote
3answers
433 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 ...
1
vote
4answers
147 views

Display both null and not null under same id but not both null or not null like XOR logic

In this table I need to select only the ids which have both null and not null values, and it should not be both not null or both are null in col1.
1
vote
2answers
6k views

How does ORDER BY FIELD() in MySQL work internally

I understand how ORDER BY clause works and how the FIELD() function works. What i want to understand is how the both of them work together to sort. How are the rows retrieved and how is the sort ...
1
vote
4answers
2k views

How to select first row from a join that returns multple rows on the primary key

This is related to this question: Joining multiple tables results in duplicate rows I have two tables that I am joining. They share a key. The person table has one name per primary key but the ...
1
vote
1answer
252 views

UPDATE with CASE with 2 tables

I have 2 tables and I want to update table2 with criteria of table1 and table2. The criteria are: 1.table1.amount > 10000 2.table2.flag is null or table2.flag = '0' So if the 2 conditions are ...
1
vote
1answer
261 views

How to set IN values on an update (SQL Server)? [closed]

Quick question, I did try to google but couldn't find an answer. I have 3 separate queries here, I want to do SET IN ('price1', 'price2', 'price3') but when I tried I got an error. How would I do ...
1
vote
2answers
171 views

Query to return zero if nothing exist

I have a table With currency, paymenttype and invoiceamount. I have to write a query to get currency, paymenttype and total invoiceamount made. This is pretty simple with group by. But actually I ...
1
vote
3answers
148 views

Clustered Index improvemens for particular queries

I found a table that looks like this: CREATE TABLE [dbo].Table1 ( id INT primary key IDENTITY (1, 1), [idUser] INT NOT NULL , [Amount] INT NOT NULL , [Attempts] INT NOT NULL , ...
1
vote
3answers
441 views

New SQL Server 2008 instance, load old instance DB's

BACK STORY: I'm a developer with a local instance of SQL Server 2008 on my workstation. I just recently upgraded my motherboard and found out (much to my dismay) the old motherboard's RAID drivers ...
1
vote
3answers
3k views

SQL Server: CONVERT From ISO8601 To DateTime Within Query

I have a Microsoft SQL Server 2008 R2 database where the DateTime column is not a datetime data type, but varchar(50). Our website logs that data and I don't really have control over it (I'm sure a ...
1
vote
1answer
408 views

Difference between COUNT(ColName) vs COUNT(ALL(ColName))

Both query return the same output: select COUNT(id) from Employee select COUNT(All(id)) from Employee So what is the difference in SQL-Server 2008R2?
1
vote
2answers
571 views

T-SQL script to perform a compressed backup with maximum compression level [duplicate]

I have a database with full backup of almost 2GB. When I perform a full backup (without compression) and then compress it with winrar it become 140MB, but when I backup WITH COMPRESSION syntax the ...
1
vote
2answers
4k views

mysql: using comma-separated values

I have a simple mysql table which I use as a server booking system. A user can log in to a server, if he has a valid booking for that server. A sample data might look like this: ...
1
vote
2answers
119 views

How to backup databases to ensure data recovery

I have 15 customer databases that have minimum replication at different sites. I currently do nightly back-ups and transfer the database back-up nightly to our main server via 7zip. We recently had ...
1
vote
4answers
1k views

Unsure how to implement certain constraints and relations in this relational database schema

I am in the middle of designing the dB for school project- airline ticketing database.(Using MySQL workbench) So far, I came up with the following design: Here are couple things I can't figure out: ...
1
vote
2answers
583 views

Database Design - One table from many source(One to One)

I have a 'Text' table, the text table may came from different source, like Tweet, SMS, Email, etc. and each source have their own log, and Text is came from the source. so i came with some solution, ...
1
vote
1answer
44 views

Capitalize only the first letter of a name

I have a table Vendors that contains a column VendorContactFname, which is written in lowercase. I want to capitalize only its first letter. I am thinking of concatenating an Upper on the first ...
1
vote
2answers
113 views

How to reformat Oracle SQL quadratic-equation solver script?

I was wondering how I might be able to tweak this SQL script: ALTER SESSION SET NLS_NUMERIC_CHARACTERS='. '; SELECT 'Not a quadratic equation.' ans FROM dual WHERE &&A = 0 UNION SELECT 'x = ...
1
vote
1answer
107 views

Error at line 1, column 25: ORA-00923: FROM keyword not found where expected

I have some code that works in Access but now I want to forward the code to our IT department to make a view in our SQL database. Could anyone please help me convert it so it is correct for normal ...