There seem to be many questions about the usage of SQL (Structured Query Language) with the ExecuteSQL function in FileMaker 12. This tutorial attempts to explain some of the SQL terms, if you are new to writing SQL statements. Since there are already many examples of how to write the ExecuteSQL queries, links to these will be listed at the end of this article. If you don’t need to learn the terms, jump right to the Helpful Example Databases section, below. There you will find links to solutions that help you create and test your queries.
This is not a complete SQL guide, as other databases may use other syntax. This is not a complete FileMaker and SQL guide, as FileMaker may be an ODBC source and the SQL queries made against it may vary from the terms used by ExecuteSQL(). This is not a complete FileMaker and ESS guide using SQL calls (if using Import or Execute SQL script steps or ExecuteSQL() function or ESS). It may not have all the nuances needed for other data sources. This is the ExecuteSQL() function reference for which you’ve been waiting. The FileMaker 12 ODBC and JDBC Guide is helpful, but it has uses outside (and beyond) the ExecuteSQL() function. Any discrepancies between the reference and the function will be noted here, if possible.
Recently I had an on-screen reporting challenge, and decided to try several different approaches to see which would be fastest. The challenge: Starting with two tables, one containing 20 Employees, and one containing 2,000 Sales records for the current year…
…display daily sales totals per employee in a seven-day grid, like so:
Update 20 Aug 2012: Dr. Noda has updated the demo files to include Rob Russell’s clever fill graphic trick (as per the responses following the article). Thank you Rob and Dr. Noda.
As promised last time, today we’re going to look at a technique from Dr. Osamu Noda, which uses FM 12’s ExecuteSQL to create what appears to be a value list when in fact there are no value lists defined at all.
This technique, like some of the others we’ve seen recently, is decidedly esoteric, but it shows some clever outside-the-box thinking, and I appreciate Dr. Noda taking the time to share the demo (ValueListWithoutDefinition-RR-Edition) and write up his notes. One of the things I particularly like about this technique is that it allows the order of the value list items to be customized, even though the values come from a table.
Folks, we have a superb demo today (MagicValueList), which comes courtesy of Andries Heylen of BH&A…
But first a bit of background. Prior to July 18, 2012, if anyone had told me you could base a value list on an unstored field, my response would have been something along the lines of…
- What app are you using? (Because it sure as heck ain’t FileMaker.)
- Why are you wasting my time with this nonsense?
- Is today April Fool’s Day?
- What are you smoking?
But then John Ahn showed this amazing Conditional Value List demo during the DevCon “Unconference” session devoted to ExecuteSQL (see previous posting), and to my way of thinking, the most intriguing part of session was only incidentally concerned with SQL, because John seemingly had achieved the impossible — a value list based on an unstored field.
11 Sep 2012: The ConditionalVL_SQL demo has been updated to fix a minor bug.
Yesterday I had the pleasure of co-presenting a DevCon “Unconference” session with John Ahn on the topic of ExecuteSQL. I wasn’t sure if there would be much interest in this somewhat geeky subject, but the room was packed, and the audience ran the gamut from SQL newbies to SQL power users.
We started out with a basic intro, and showed a few simple demos. Next we moved on to a discussion of some of the issues, nuances, gotchas, etc. Then John showed a couple ExecuteSQL-powered demos which I strongly commend to your attention: a) Multi-Column Dynamic Portal Sorting…
…and b) Dynamic Value Lists…
…which, incidentally, caused every jaw in the room to drop, due to the fact that John’s method of constructing these conditional value lists seems to violate at least one fundamental law of FileMaker physics — more on this in an upcoming posting.
Here are links to everything we referred to during the presentation, in roughly chronological order.
FileMaker Hacks postings:
John Ahn’s demos:
A few months ago I mentioned “dwindling value lists” in passing, and said I would do a proper article on them at some point in the future. Well, then FM 12 was released and I went on an ExecuteSQL binge, so I’m just now getting around to honoring my promise.
Dwindling Value Lists (DVLs) are value lists that shrink up, by removing individual list items as they are selected. They can come in very handy when you need to schedule resources and want to prevent double booking. This example comes from one of today’s demo files, Dwindling Value Lists, and shows how a DVL might be used to schedule employees for a work shift.
Essentially, a DVL is a filtered value list that updates in real time (or something very close to real time), and this is done by building a multiline key of selected values, and then filtering the VL to only show remaining eligible values. Continue reading
In part 1, I listed six scenarios that could potentially cause ExecuteSQL code to break:
…and managed to get through the first five before running out of steam. This time, we’re going to examine #6 on the list, and then look at a few miscellaneous odds ’n’ ends, and today’s demo file is ExecuteSQL Sandbox, v2, if you’d like to follow along.
Changing a Field Type
Why would changing a field’s type cause a problem? Well, first off, as I mentioned last month, if you are using that particular field as a predicate in a JOIN, the query will break, and your reward will be the the dreaded “?”.
I don’t have a fix for this, just some advice: Don’t change a field’s type if you’ve used it as a JOIN predicate in a working SQL statement. (The only reason I’ve needed to change a field type recently was to fix a broken JOIN where the field types were mismatched.)
[Note: Some of the material in this article, and in today’s demo file ExecuteSQL Sandbox, previously appeared in my March 2011 article, Custom Functions for Internal SQL.]
The other day a colleague remarked, “You know, it’s going to be interesting to see if you SQL guys are still so excited about ExecuteSQL when something gets renamed and your code breaks.” He had a good point: code is “brittle” if it works initially, but then subsequently breaks as a result of a seemingly innocuous action.
Here are some things that can cause ExecuteSQL code to break:
- Renaming a table occurrence (TO)
- Renaming a field
- Using a “reserved word” as a field or TO name
- Having a problematic character in a field or TO name
- Executing the code in a foreign country (!)
- Changing a field’s type (e.g., from text to number or vice versa)
…and today we’re going to look at some defensive measures we can employ to prevent problems when these things occur.
Using the “orders” table in the demo file…
This is a quick follow-up to part 1, with a couple more observations about dynamic parameters.
Here’s one I can’t believe I forgot to mention the other day: A major ExecuteSQL headache that dynamic parameters can alleviate is the dreaded “embedded apostrophe” problem. In case you aren’t familiar with it, if your text string contains an embedded apostrophe, in standard SQL you must escape it by prepending another apostrophe, for example compare these two “standard” (non-dynamic) queries:
As you might expect, you don’t have to worry about this if you instead use a dynamic parameter… just quote the search term the way you would any FileMaker text string (i.e., in double quotes) and go about your business.
I have a confession: when I first read about dynamic parameters in the Help entry for ExecuteSQL, my initial reaction was, “Why do they have to make it so darn complicated?”
I have another confession: I am now singing a very different tune. I’ll get to the reason for this in a minute, but first let’s compare two ExecuteSQL statements, which were discussed last month in FM 12 ExecuteSQL, part 1.