[Solved] Calculated Fields in Base

[Hagar Delest]

Hi

In my Members table I have a DOB category and an AGE category and I would like the AGE to be a calculated field based upon the DOB and the current date. In a spreadsheet the formula is =YEAR(NOW()-"the DOB cell")-1900 but I do not think there is an equivalent formula in SQL.

The DATEDIFF function using the DOB and the current date appears to be the way forward but bearing mind I need a number not a date i am unsure how to achieve this in SQL.

Any help or guidance will be appreciated.

grabro

[Arineckaig]

Some functions for Base and HSQL can be found at:
http://wiki.services.openoffice.org/wiki/Built-in_functions_and_Stored_Procedures#Date_and_Time_Functions

[Sliderule]

You said / asked:

I would like the AGE to be a calculated field based upon the DOB and the current date.

Assuming the name of the field in your database is "Date of Birth" ( if not, change the code below to reflect the Field name in your Database Table ) . . . the following calculation will return an Age in years ( whole number ).

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DATEDIFF('YY', "Date of Birth", CURRENT_DATE) - CASEWHEN((MONTH("Date of Birth")*100 + DAYOFMONTH("Date of Birth")) > (MONTH(CURRENT_DATE)*100 + DAYOFMONTH(CURRENT_DATE)),1,0)

Important Note: The formula you showed above ( =YEAR(NOW()-"the DOB cell")-1900 ) for a Spreadsheet . . . will provide invalid values. For example . . . assume today in YYYY-MM-DD format is 2010-11-21 . . . if "the DOB cell" is 2008-11-20 or 2008-11-21 . . . incorrect values are returned .

I hope this helps, please be sure to let me / us know.

Sliderule

Thanks to add [Solved] in your 1st post Subject (edit button top right) if this issue has been resolved.

[grabro]

Sliderule

Thank you for your help. I am sure this will work if only I can now work out the SQL syntax for it. Those I have trie keep giving me an error.

Incidentally in MYSQL the following query works OK

SELECT Members SET AGE=((DATEDIFF(CURDATE(),DOB))/365 where ID<609

I'll get there eventually

grabro

[Sliderule]

grabro:

You comment above does not make sense to be. Please be specific . . . ¿ ¿ ¿ what is your database engine . . . is it HSQL ( the default used by OpenOffice Base ) . . . or . . . MySQL ( which you mentioned in your above post ) . . . or some other Database Engine ? ? ?

Please tell me EXACTLY what the status bar at the bottom displays, after you open your OpenOffice *.odb file?

Sliderule

[grabro]

Sliderule

Sorry i was unclear. I am using HSQL. The database was developed by Openoffice Base. My reference to Mysql was mainly because I was under the impression that the SQL syntax was standard throughout all databases.

Originally I was using Mysql but I could not get it to work through oOo Base; it does not recognize the JBDC files. Accordingly I set up the oOoBase system as i am hoping that eventually it will be set up so that people used to Microsoft Access can use it without any problems.

So, Ignore my reference to Mysql.

grabro

[Sliderule]

Since you are using HSQL ( my original assumption ) as your database engine . . . you may use EITHER of code samples below to calculate AGE . . . but change "Date of Birth" ( three times ) to the actual field in your database table:

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DATEDIFF('YY', "Date of Birth", CURRENT_DATE) - CASEWHEN((MONTH("Date of Birth")*100 + DAYOFMONTH("Date of Birth")) > (MONTH(CURRENT_DATE)*100 + DAYOFMONTH(CURRENT_DATE)),1,0)

     or

YEAR(CURRENT_DATE) - YEAR("Date of Birth") - CASEWHEN(MONTH(CURRENT_DATE)*100 + DAYOFMONTH(CURRENT_DATE) >= MONTH("Date of Birth")*100 + DAYOFMONTH("Date of Birth"),0,1)

Please be sure to let me / us know.

Sliderule

Thanks to add [Solved] in your 1st post Subject (edit button top right) if this issue has been resolved.

[iqullc]

Hello Sliderule,

Your sample code looks like it would solve my challenge, not quite sure. I want the same as the originator of the thread, a number/age. The difference is I want it to display in a form. Where would I put it...in the Control or on the form with the Control? As usual your help is appreciated.

[Villeroy]

Code: Select all   Expand viewCollapse view

SELECT *,
DATEDIFF('YY', "Date of Birth", CURRENT_DATE) - CASEWHEN((MONTH("Date of Birth")*100 + DAYOFMONTH("Date of Birth")) > (MONTH(CURRENT_DATE)*100 + DAYOFMONTH(CURRENT_DATE)),1,0) AS "Age"
FROM "YourTable"

Returns everything from "YourTable" plus a calculated field "Age". Replace your form source with this query.

[iqullc]

Wow thanks Villeroy for the quick reply...trying it out. Will let you know.

[iqullc]

Villeroy/Sliderule,

I got the following syntax error message:

Unexpected "" expecting From or INTO

When opening the Form.

[Sliderule]

iqullc:

You said:

I got the following syntax error message:

Unexpected "" expecting From or INTO

Therefore, you made a mistake. Since, you have elected NOT to inform us exactly what your Query looks like, the only answer, based on the information you have provided is, you made a mistake.

Sliderule

[iqullc]

Oops...I thought you could see the thread.

SELECT *,
DATEDIFF('YY', "Date of Birth", CURRENT_DATE) - CASEWHEN((MONTH("Date of Birth")*100 + DAYOFMONTH("Date of Birth")) > (MONTH(CURRENT_DATE)*100 + DAYOFMONTH(CURRENT_DATE)),1,0) AS "Age"
FROM "YourTable"

I replaced "Date of Birth" with "Bday" and "your table" with "Patients"

[Sliderule]

I asked you to show us EXACTLY the SQL you wrote . . . and . . . you replied above:

Code: Select all   Expand viewCollapse view

SELECT *,
DATEDIFF('YY', "Date of Birth", CURRENT_DATE) - CASEWHEN((MONTH("Date of Birth")*100 + DAYOFMONTH("Date of Birth")) > (MONTH(CURRENT_DATE)*100 + DAYOFMONTH(CURRENT_DATE)),1,0) AS "Age"
FROM "YourTable"

Change the above to:

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SELECT "Patiens".*,
DATEDIFF('YY', "Bday", CURRENT_DATE) - CASEWHEN((MONTH("Bday")*100 + DAYOFMONTH("Bday")) > (MONTH(CURRENT_DATE)*100 + DAYOFMONTH(CURRENT_DATE)),1,0) AS "Age"
FROM "Patients"

Explanation: Since, you want to include all of the columns ( fields ) from the table "Patients" in the RESULT SET, you should include that table name BEFORE the * in the Query. I replaced the table name to "Patients, and, the column containing the date to, "Bday" .

Sliderule

[Villeroy]

Try the joker with table name:
SELECT "Patients".*, ...etc...

[iqullc]

Fabulous, thanks Sliderule and Villeroy. Everything is working.

On the calculation script and error message...duh on my part

See you around the Forum.

Stephanie

[Quadium]

Thanks Sliderule! Just downloaded Base today and needed the Age calculation. Worked perfect first time. Just need something that will return 'blank' when there is no birthday. Steep learning curve! ;>)

[Sliderule]

Thanks Sliderule! Just downloaded Base today and needed the Age calculation. Worked perfect first time. Just need something that will return 'blank' when there is no birthday. Steep learning curve! ;>)

Welcome to the OpenOffice / LibreOffice Base forum.

Use the following code:

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SELECT
   "Patients".*,
   COALESCE(DATEDIFF('YY', "Bday", CURRENT_DATE) - CASEWHEN((MONTH("Bday")*100 + DAYOFMONTH("Bday")) > (MONTH(CURRENT_DATE)*100 + DAYOFMONTH(CURRENT_DATE)),1,0),NULL) AS "Age"
FROM "Patients"

Explanation: Using the COALESCE function, which says, if the first argument is NOT NULL, use it, otherwise, return the second argument . . . in this case . . . NULL .

Sliderule

[Quadium]

Sliderule - When I use DATEDIFF( 'YY', "G_DateOfBirth", CURRENT_DATE ) - CASEWHEN( ( MONTH( "G_DateOfBirth" ) * 100 + DAYOFMONTH( "G_DateOfBirth" ) ) > ( MONTH( CURRENT_DATE ) * 100 + DAYOFMONTH( CURRENT_DATE ) ), 1, 0 ) in the Field of a Query, with Age as the Alias, it returns the Age properly, but Age is 0 when DateOfBirth is blank. When I try to modify it to COALESCE(same as previous,NULL) I get an error: The column 'COALESCE(DATEDIFF( 'YY', "G_DateOfBirth", CURRENT_DATE ) - CASEWHEN( ( MONTH( "G_DateOfBirth" ) * 100 + DAYOFMONTH( "G_DateOfBirth" ) ) > ( MONTH( CURRENT_DATE ) * 100 + DAYOFMONTH( CURRENT_DATE ) ), 1, 0 ),NULL)' is unknown. What am I doing wrong?

[Sliderule]

Please note, in my opinion, your database should NEVER have a NULL ( undefined ) value, whether with a TEXT column, a DATE column, a TIME column, a TIMESTAMP column, a BOOLEAN column, nor, a NUMERIC column.

Try the following code:

Code: Select all   Expand viewCollapse view

SELECT
   "Patients".*,
   CASE WHEN "Bday" IS NULL THEN NULL ELSE DATEDIFF('YY', "Bday", CURRENT_DATE) - CASEWHEN((MONTH("Bday")*100 + DAYOFMONTH("Bday")) > (MONTH(CURRENT_DATE)*100 + DAYOFMONTH(CURRENT_DATE)),1,0) END CASE AS "Age"
FROM "Patients"

Or, perhaps the following code . . . that MUST be run withOUT the Base Parser:

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SELECT
   "Patients".*,
   CASEWHEN ("Bday" IS NULL, NULL, DATEDIFF('YY', "Bday", CURRENT_DATE) - CASEWHEN((MONTH("Bday")*100 + DAYOFMONTH("Bday")) > (MONTH(CURRENT_DATE)*100 + DAYOFMONTH(CURRENT_DATE)),1,0))  AS "Age"
FROM "Patients"

Explanation: Changed from the previously posted COALASE function to a CASE WHEN . . . THEN . . . ELSE . . . END CASE statement.

I hope this helps, please be sure to let me / us know.


Sliderule

[Quadium]

Sliderule - Same error message for both new suggested formulas. If you can access my e-mail address, send me a quick note, and I'll forward the database. It's a small one I created just to start learning what I need. Thx.