©M.J.S.
For some reason the ability to handle NULLS in SQL statements can confuse some. This article takes a look at how to think of NULLs. 

For some reason the value of NULL has confused many and even started feuds across the Internet for the [...]

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©tracyhunter

We might not be breaking glass like the old Memorex commercials but Sony has opened that door for us to think about broken glass again. At about $10,000 Sony will be unveiling a high-end glass speaker system. Yes glass! The glass tube is [...]

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©cogdogblog
Grouping and summing at multiple levels often takes an application to perform. Take a look at the ROLLUP operation within Oracle and perform these operations in a single SQL statement.

Grouping and in particular gathering aggregates across groups often brings confusion to many practitioners. [...]

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©cogdogblog
Whether they are called hierarchical structures, trees, or self-referencing tables they often pose quite a challenge to traverse in any simple manner. But Oracle has a solution.

It is not a question as to whether or not hierarchical models are good or bad. We will all come across them no matter where we go. But querying [...]

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©cogdogblog
A pseudocolumn is a column that looks like a column but really isn’t a column. What! Stick around and find out what a pseudocolumn really is.

The best way to describe what a pseudocolumn is would be to take two of Oracle’s most popular pseudocolumns and explain their use. These two pseudocolumns being ROWID and ROWNUM. [...]

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©cogdogblog
How many do I have? Do I have at least one? What’s the greatest? What’s the least? Give me the top 5 rows. These are just some of the types of questions that are often asked when trying to evaluate table data.

Many of the problems I see in answering reporting questions, and everyday DBA work, [...]

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©cogdogblog
As your database grows so will the need to get information from more than one table. This article shows you the different join options and some simple examples to raise your familiarity.

Wouldn’t it be nice if every piece of data were stored in one table? Well this is obviously never going to happen. The simple [...]

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©azrainman
Isn’t it always the case. Someone gets caught or put under the spotlight and THEN something gets done. It’s no different for the high ranking U.S. Health officials. After taking a lashing for not finding problems with drugs or medical devices quick enough they have sought the help of a data system called Sentinel.

Sentinel will, [...]

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©cogdogblog
We do not always want to SELECT everything from a table. The matter of finding the information required is a function of implementing the optional WHERE clause of the SELECT statement.

In the previous Part II of this series we took a look at the “simple SELECT’ statement. This involved the four required pieces of a [...]

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©cogdogblog
Most often we query information from a database where that information is stored inside a table structure. Most explain a table as a series of rows and columns. Much like a spreadsheet where the spreadsheet is the TABLE, each line (horizontally down the page) in the spreadsheet is considered a ROW, and then sets of [...]

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