Count the Number of Weekend Days between Two Dates
Handling weekends can be tricky in SQL. This article shows you how to Count the Number of Weekend Days between Two Dates
2020-10-16 (first published: 2018-08-23)
12,633 reads
Adam Aspin
Creating Subtotals and Totals in Aggregated Queries
Grouping Sets are an effective way to add subtotals to aggregated queries. T His article explains how.
2020-09-25 (first published: 2018-09-06)
11,444 reads
Aggregate Data for the Last Day of the Month
On some occasions you will need to aggregate Data for the Last Day of the Month. This article explains how.
2020-04-03 (first published: 2018-08-16)
6,897 reads
Displaying Hierarchical Data
Producing hierarchies from SQL tables can necessitate joining a table to itself. This article will explain how you can do this.
2020-03-06 (first published: 2018-08-30)
24,776 reads
Using a CTE as a Tally Table
Sometimes you need to output blank lines
- in effect displaying Records for Missing Data. This article explains how to use a CTE to do this
2018-08-09
4,743 reads
Using a Derived Table to Compare Data with Values from a Previous Year
Comparing year on year sales is a fundamental requirement in much commercial analysis - here you learn how to do this in SQL
2018-08-02
3,304 reads
Display Median Values
DO you know how to display median values from a Dataset? In this short article you will use windowing functions to do this
2018-07-26
1,773 reads
Segment Data into Deciles
This short article shows a simple example of how to segment data into deciles
2018-07-19
10,918 reads
Generating Completely Random Sample Output from a Dataset
This short article shows a simple example of how to generate completely random sample output from a Dataset
2018-07-12
6,885 reads
Creating Compound Interest Calculations in SQL
This is the first article in a short series of SQL Server query challenges to test and expand your SQL Server querying skills
2018-07-05
20,263 reads
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Question of the Day
The string_agg function
We create the following table and then insert some records in it:
create table t1 ( id int primary key, category char(1) not null, product varchar(50) ); insert into t1 values (1, 'A', 'Product 1'), (2, 'A', 'Product 2'), (3, 'A', 'Product 3'), (4, 'B', 'Product 4'), (5, 'B', 'Product 5');What happens if we execute the following query in both Sql Server and PostgreSQL?
select id,
category,
string_agg(product, ';')
over (partition by category order by id
rows between unbounded preceding and unbounded following) as stragg
from t1; See possible answers