When creating indexes on tables, it is always best to choose columns that have a high degree of selectivity, or uniqueness. This SP, ShowUniqueness, gives the user an easy way to determine the "uniqueness" percentage of a given column or combination of columns.
2002-10-23
468 reads
My stored procedure, sp_dbsettings, allows you to view, in a cross-tabular format, all the common options and their values for all the databases on your server. Optionally, you can pass a database name as an argument if you just want to view the settings for one database (i.e., EXEC sp_dbsettings 'Northwind'). Otherwise it shows info […]
2002-10-09
649 reads
T-SQL's CHARINDEX() function is a useful for parsing out characters within a string. However, it only returns the first occurrence of a character. Oftentimes one needs to locate the Nth instance of a character or a space, which can be a complicated task in standard T-SQL. This function I wrote, imaginatively named CHARINDEX2(), allows one […]
2002-09-27
32,440 reads
The sp_for procedure provides simple single-statement loop processing for T-SQL statements, similar to the FOR command in the C language or the DOS command-line utility by the same name.It's syntax is similar to that of the DOS command. It takes an argument to represent a variable, initialize the variable, set an increment, set an end […]
2002-09-13
907 reads
SQL Server's COUNT() function is a slow and expensive way to count a table's rows because it scans the entire table or index. FASTCOUNT(), which I created, is much more efficient for this purpose - its only drawback being that it may return inaccurate results if a nonlogged (e.g., bulk) data modification operation was recently […]
2002-09-10
858 reads
Let's say you have 2 tables: a Contacts table and a PhoneNumbers table (which stores all the phone numbers for each contact). You are asked to write a query that returns each contact's name and a comma-delimited string of phone numbers for each contact, something like this:FirstName LastName PhoneNumbers--------- -------- --------------------------John […]
2002-07-22
1,035 reads
Say you wanted to create an SP for updating records in a database. How would you do this in such a way as to allow your users to edit only a subset of fields in the record, without overwriting the other fields, and without requiring verbose IF blocks and CASE statements in your code?Simple. Use […]
2002-04-16
211 reads
This short and simple script is a very fast way to count the rows in all your indexed tables. I ran it against a 2-gigabyte database containing large tables (some with over a million rows!), and it returned results in under a second.
2002-03-12
2,884 reads
By James Serra
I’m honored to be hosting T-SQL Tuesday — edition #192. For those who may...
By Vinay Thakur
Continuing from Day 2 , we learned introduction on Generative AI and Agentic AI,...
Quite the title, so let me set the stage first. You have an Azure...
hi everyone I am not sure how to write the query that will produce...
Comments posted to this topic are about the item Rollback vs. Roll Forward
Comments posted to this topic are about the item Foreign Keys - Foes or...
I have some data in a table:
CREATE TABLE #test_data
(
id INT PRIMARY KEY,
name VARCHAR(100),
birth_date DATE
);
-- Step 2: Insert rows
INSERT INTO #test_data
VALUES
(1, 'Olivia', '2025-01-05'),
(2, 'Emma', '2025-03-02'),
(3, 'Liam', '2025-11-15'),
(4, 'Noah', '2025-12-22');
If I run this query, how many rows are returned?
SELECT *
FROM OPENJSON(
(
SELECT t.* FROM #test_data AS t FOR JSON PATH
)
) t; See possible answers