The task is to build a tree in a table with parentID from bottom to top. It's useful for generating hierarchy strings, lists or any other types. You can also create a storage procedure of this and it will make it easy to use in queries.
(read more...)There are at least 3 ways to find out if the column in table exists in MS SQL server. It's a common task for developers or administrators when you need to modify table.
There's a column Photo with type "Image" in MS SQL table (database – MS SQL Server 2008 R2). The task is to get all the records where Photo is empty. Values of empty images is "0x00000000".
To receive quantity of rows of the returned records of SQL query, you should use function @@ROWCOUNT. Function @@ROWCOUNT returns the quantity of rows, which were used in a query.
How to get as SQL query result the list of databases in SQL server.
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select name, database_id from sys.databases |
When you modify columns of a table in MS SQL management studio, you got the message "Saving changes is not permitted. The changes you have made require the following table to be dropped and re-created … " (Figure 1). The reason of this is re-creating of table. It's really important for productive environment but not very for test ones.
It’s a little tutorial about how to get all duplicate records on namesakes example from your database table. For example, we have a table with columns Id, FullName, Birthdate and Phone.
Using 'GROUP BY' and 'HAVING' we can select all namesakes. (read more...)
Concatenating of string columns is not very simple task in T-SQL if you don’t know ANSI standart of it. According to ANSI standart of SQL, concatenating of NULL-value is NULL in the result. It’s not clearly for developer, but it is so.
Let’s see some features for work with concatenating NULL-value columns. For example, I will use tutorial database Northwind and its table Customers. (read more...)
In this post I will write about SQL conditions. It seems to me that construction "IF ... ELSE" you can find in any language. Transact SQL is not exclusion.
Let’s see IF ... ELSE in action on the sample below. (read more...)
There are several ways to make a copy of database table in MS SQL Server. I write down some ways to make a copy of table. Which way to choose is your choice according to table structure, indexes and your wish to make something manually. (read more...)
