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Posts Tagged ‘SQL Server’

Comma separated values in mysql


MY SQL:

GROUP_CONCAT function concatenates values within each group defined by GROUP BY clause.

Syntax GROUP_CONCAT([DISTINCT] exp [ORDER BY sorting] [SEPARATOR ‘sep’])
Quick Example SELECT GROUP_CONCAT(city) FROM cities GROUP BY state;
Separator Comma (,) by default, ” eliminates separator
NULL Values Skipped
Max Length 1024 by default, specified by group_concat_max_len system variable

Sample:

CREATE TABLE cities
   (
     city VARCHAR(70),
     state CHAR(2)
   );
 
   INSERT INTO cities VALUES ('San Francisco', 'CA');
   INSERT INTO cities VALUES ('San Diego', 'CA');
   INSERT INTO cities VALUES ('Los Angeles', 'CA');
 
   INSERT INTO cities VALUES ('Austin', 'TX');
   INSERT INTO cities VALUES ('Houston', 'TX');

   SELECT state, GROUP_CONCAT(city)
   FROM cities
   GROUP BY state;
The result:
CA San Francisco,San Diego,Los Angeles
TX Austin,Houston
SQL Server:
SELECT state,
STUFF((SELECT ',' + city FROM cities WHERE state = c.state FOR XML PATH('')),1 ,1 ,'')
FROM cities c
GROUP BY state

Hope this help !
Rahul Bhatia

SQL: Alter script to change the Primarykey Column datatype

February 23, 2015 Leave a comment

–This will drop the primary key constraint
ALTER TABLE [pTARGET_TYPE] DROP CONSTRAINT PK_TARGET_TYPE

–Alter datatype
ALTER TABLE [TARGET_TYPE] ALTER COLUMN [TARGET_TYPE_ID] INT NOT NULL

–Add Primary key constraint
ALTER TABLE [TARGET_TYPE] ADD CONSTRAINT PK_TARGET_TYPE PRIMARY KEY ([TARGET_TYPE_ID])

Visual Studio – Database Project Not Loading


Have you ever created a Database project and after some time you are not able to load it in the Visual Studio? Probably you might be getting following error:

An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: SQL Network Interfaces, error: 26 – Error Locating Server/Instance Specified)

The database project requires an active database connection to load at design time. Probably it uses that to compile/verify scripts. The problem here is Visual Studio is not able to connect to any such instance. Following are few solutions (these worked for me)

  1. Make sure the instance to which you want to connect is running and allows remote connections.
  2. After performing step 1, if it is still not loading then you may need to start the SQL Browser Service. Make sure it’s running.
  3. If the problem is still there, it has to be fixed from Visual Studio itself. Actually database project do not store to which instance it can connect. It’s a Visual Studio setting.In VS2008 go to Tool > Options > Database Tools > Design-time Validation Database > Connection Options. Specify your instance name here like “\SQLEXPRESS”

Also If you upgraded your database project from 2005 to 2008 and if  you try to open the 2008 database project solution file then you may get the following error:

Coluld not load file or assembly ‘System.Data.SqlServerCe, Version=3.5.1.0, Culture=neutral, PublicKeyToken = 89845dcd8080cc91’ or one of its dependencies. The system cannot find the file specified.

To resolve this you need to install SQL Server CE 3.5 SP1 from here: http://www.microsoft.com/downloads/details.aspx?FamilyID=dc614aee-7e1c-4881-9c32-3a6ce53384d9&displaylang=en

Hope it helps !