Database Administrators Stack Exchange
Database Administrators Stack Exchange

Questions tagged [t-sql]

Transact-SQL (T-SQL) is a dialect of SQL used by Microsoft SQL Server and SAP's Sybase.

From SQL Server Books Online:

Transact-SQL is the language used to administer instances of the SQL Server Database Engine, to create and manage database objects, and to insert, retrieve, modify, and delete data.

Transact-SQL is an extension of the language defined in the SQL standards published by the International Standards Organization (ISO) and the American National Standards Institute (ANSI).

References

3002 questions
480
votes
2 answers

What's the difference between a temp table and table variable in SQL Server?

This seems to be an area with quite a few myths and conflicting views. So what is the difference between a table variable and a local temporary table in SQL Server?
Martin Smith
  • 80,333
  • 15
  • 230
  • 323
100
votes
6 answers

Retrieving n rows per group

I often need to select a number of rows from each group in a result set. For example, I might want to list the 'n' highest or lowest recent order values per customer. In more complex cases, the number of rows to list might vary per group (defined by…
Paul White
  • 78,233
  • 28
  • 392
  • 615
77
votes
1 answer

MERGE a subset of the target table

I am trying to use a MERGE statement to insert or delete rows from a table, but I only want to act on a subset of those rows. The documentation for MERGE has a pretty strongly worded warning: It is important to specify only the columns from the…
KutuluMike
  • 1,559
  • 2
  • 14
  • 13
62
votes
6 answers

Date range rolling sum using window functions

I need to calculate a rolling sum over a date range. To illustrate, using the AdventureWorks sample database, the following hypothetical syntax would do exactly what I need: SELECT TH.ProductID, TH.TransactionDate, TH.ActualCost, …
Paul White
  • 78,233
  • 28
  • 392
  • 615
61
votes
4 answers

Does SQL Server CASE statement evaluate all conditions or exit on first TRUE condition?

Does the SQL Server (2008 or 2012, specifically) CASE statement evaluate all the WHEN conditions or does it exit once it finds a WHEN clause that evaluates to true? If it does go through the entire set of conditions, does that mean that the last…
Juan Velez
  • 3,195
  • 15
  • 49
  • 69
53
votes
2 answers

How to create Unicode parameter and variable names

All of this works: CREATE DATABASE [¯\_(ツ)_/¯]; GO USE [¯\_(ツ)_/¯]; GO CREATE SCHEMA [¯\_(ツ)_/¯]; GO CREATE TABLE [¯\_(ツ)_/¯].[¯\_(ツ)_/¯]([¯\_(ツ)_/¯] NVARCHAR(20)); GO CREATE UNIQUE CLUSTERED INDEX [¯\_(ツ)_/¯] ON…
Brent Ozar
  • 42,296
  • 45
  • 201
  • 356
53
votes
4 answers

What's the easiest way to create a temp table in SQL Server that can hold the result of a stored procedure?

Many times I need to write something like the following when dealing with SQL Server. create table #table_name ( column1 int, column2 varchar(200) ... ) insert into #table_name execute some_stored_procedure; But create a table which…
Just a learner
  • 2,522
  • 6
  • 32
  • 49
49
votes
8 answers

Writing select result to a csv file

We need to write the SELECT query results to a csv file. How can it be done using T-SQL in SQL Server 2008 r2? I know that it can be done in SSIS, but for some reasons, we don't have this option. I tried to use the suggested proc in the article…
Sky
  • 3,674
  • 16
  • 48
  • 68
46
votes
9 answers

Asked to Not Use Transactions and to Use A Workaround to Simulate One

I've been developing T-SQL for several years and am always digging in further, continuing to learn all I can about all aspects of the language. I recently started working at a new company and have received what I think is an odd suggestion regarding…
Forrest
  • 401
  • 4
  • 5
42
votes
4 answers

Table-Valued Parameter as Output parameter for stored procedure

Is it possibile to Table-Valued parameter be used as output param for stored procedure ? Here is, what I want to do in code /*First I create MY type */ CREATE TYPE typ_test AS TABLE ( id int not null ,name varchar(50) not null ,value…
adopilot
  • 2,393
  • 6
  • 30
  • 44
39
votes
1 answer

GO After every T-SQL statement

What is the reasoning behind using the GO statement after every SQL statement? I understand that GO signals the end of batch and/or allows the reputation of statements but what advantage does it have using it after every statement. I am just…
TheIdiot
  • 491
  • 1
  • 4
  • 4
39
votes
5 answers

Logical operators OR AND in condition and order of conditions in WHERE

Let's examine these two statements: IF (CONDITION 1) OR (CONDITION 2) ... IF (CONDITION 3) AND (CONDITION 4) ... If CONDITION 1 is TRUE, will CONDITION 2 be checked? If CONDITION 3 is FALSE, will CONDITION 4 be checked? What about conditions on…
garik
  • 6,652
  • 10
  • 42
  • 56
38
votes
8 answers

Does SQL Server support GREATEST and LEAST, if not what is the common workaround?

Reviewing this question it seems like that's a lot of work that shouldn't be needed. They're trying to extend a range with a date. In other databases, you would just use greatest and least.. least(extendDate,min), greatest(extendDate,max) When I…
Evan Carroll
  • 59,330
  • 43
  • 219
  • 447
37
votes
2 answers

What is a WITH CHECK CHECK CONSTRAINT?

I have some auto-generated T-SQL, which is probably valid, but I don't really understand. ALTER TABLE [dbo].[MyTable] WITH CHECK CHECK CONSTRAINT [My_FORIEGN_KEY]; I know what a foreign key constraint is, but what's the CHECK CHECK?
BanksySan
  • 921
  • 1
  • 10
  • 16
35
votes
7 answers

How can I tell if a SQL Server database is still being used?

We're looking to decommission a SQL Server instance which has a couple databases still remaining on it. How can I tell if they are still being used by users or a web application? I found a forum thread which had a T-SQL query you could run to…
jsauni
  • 1,030
  • 1
  • 11
  • 15
1
2 3
…
99 100