We have a multi-threaded process that grabs it’s fair share records and then processes them. It basically looks at the total number of records to process, and takes the top 10% of the records and marks them so that no other process will grab those records. If you haven’t done a lot with TOP, then…
Tag: SQL201
Inter-Database Queries
I’ve had this question come up a few times now. “How do I copy data from one database to another?” It’s after getting a question like that, I explain fully qualified database object names. That’s a mouthful! Basically it’s a fancy way of saying the “full name” of a database object, like a table or…
SQL 201 — CREATE PROCEDURE
Now that you have the basics of SQL, I think it’s time to learn something a bit more involved. If you need to accomplish a task within SQL you will run a series of T-SQL statements. If you want to run those same steps over and over again, you could save them to a file,…
SQL 201 – CREATE TABLE
CREATE TABLE I’ve showed you how to get data out of a table, put data in, change it, and delete it. But I haven’t showed you how to create your own table….until now. CREATE TABLE tableName ( columnName <datatype> ) This statement is pretty straightforward, you have to choose the name of the table, and…
Moving Data Between Tables
Very early into my SQL career I had to get comfortable moving records around between tables and databases. There are several ways to do it, you just have to get used to some of the requirements in moving the records. Moving records into a temporary table The first time you move records, you’ll probably need…
SQL 201 – Combining Query Results
Overview There comes a point in your SQL career where you will need to combine the results of several queries into one data set, and present it in one view. When you get to this point, you’ll need to be familiar with the UNION command. With Microsoft SQL 2005, there are two new functions, similar…
SQL 201 – Sub Queries
Sub queries or nested queries are complete queries wrapped inside of another complete query. Some times this technique is used as a replacement for a JOIN statement. Some times it’s the only way to define exactly what you you want to get from a database. The important thing to learn about sub queries is they…
SQL 201 – String Manipulation Functions
In a previous post I introduced you to calculated fields, and mentioned there were many other functions you could use to compute values or columns. It’s time to introduce you to the eight most used functions when it comes to manipulating strings in SQL LEFT and RIGHT If you ever need the first 3 or…
String Manipulation — CAST and CONVERT
So far I’ve shown you just a few of the many string manipulation functions available in Microsoft SQL. Today we’re adding two more of these tools to your tool belt. CAST and CONVERT. These two become useful when you’ve stored a value as one data type, and later find you need it used as another. …
String Manipulation — REPLACE, PATINDEX and Regular Expressions
In the previous SQL posts, I showed you SUBSTRING, then I showed you REPLACE. Now, with REPLACE, you had to know what characters you wanted to replace. What if you only knew what characters you wanted to keep? Well, let me introduce you to PATINDEX. This is an advanced command that is easy to learn,…