Conditional reload

[#1]

Hi,

This is the case. I need to do conditional reload. I have a table with last source database update date. This is one row table. i need the script to compare two dates - todays date and last database update date. If todays date =last update date i want the script to reload data, if not I want to exit script and save the appliaction with old data.

Any ideas?

[sparur]

Hello.

If I understand, you need such as:

tmpLastUpdateDate:

LOAD [Last Update Date]; SQL SELECT "Last Update Date" FROM SystemTable;

LET vLastUpdDate = peek('Last Update Date', 0);

IF $(vLastUpdDate = Today(1) THEN

//load your data from DB

LOAD ... FROM...

ELSE

exit script;

END IF;

[#3]

Thanks. It seems to be good idea for one LOAD statement but I am not sure if it will work with whole script (more LOAD statements). Can I put more load statements sth like this

IF $(vLastUpdDate = Today(1) THEN

//load your data from DB

LOAD ... FROM...

LOAD ... FROM...

LOAD ... FROM...

LOAD ... FROM...

LOAD ... FROM...

ELSE

exit script;

END IF;

???

[sparur · Accepted solution]

Of course, you can.

[prabhu0505]

This is an example from reference manua page no. 502

QV_Table:

SQL SELECT PrimaryKey, X, Y FROM DB_TABLE

WHERE ModificationTime >= #$(LastExecTime)#

AND ModificationTime < #$(BeginningThisExecTime)#;

Concatenate

LOAD PrimaryKey, X, Y FROM File.QVD;

STORE QV_Table INTO File.QVD;

I hope this may be useful.

[#6]

Hey michal,

How did you achieve this?

For me the exit script will exit from the script and save the qvw with no data.

How can I retain the old data? ie, how can exit from script without saving the document?

Regards,

Robins.

PS: I am reloading the document using QV 9.0 Server Management console.

[Anonymous]

Hi,

I am trying to do a similar thing.  Test my table and if happy let the standard reloads occur.

But, if my test of the table fails I want to exit the script without saving so that the last good version stays good.

The code below checks that the table has >= 44 million rows.  The IF statement works and exits the script but wipes all content from the current tables. 

I need to keep the content of my QVW if the script exits. 

How do I do this?

LOAD

          ROWCounted;

SQL SELECT COUNT(*) AS ROWCounted

  FROM [HealthCentral].[dbo].[WaitingListHistory];

LET vRowCount =   peek('ROWCounted',0);

IF $(vRowCount) < 44000000000 THEN

     Exit Script;

END IF

[#8]

Hi John,

In your instance, Prabhu's example would like something like this:

LOAD

          ROWCounted;

SQL SELECT COUNT(*) AS ROWCounted

  FROM [HealthCentral].[dbo].[WaitingListHistory];

LET vRowCount =   peek('ROWCounted',0);

IF $(vRowCount) < 44000000000 THEN

     WaitingListHistory:

     LOAD a, b, c FROM File.QVD (QVD);

ELSE

     WaitingListHistory:

     LOAD

     SQL SELECT a, b, c FROM [dbo].[WaitingListHistory];

END IF

STORE WaitingListHistory INTO File.qvd (QVD);

[Anonymous]

Michael,

thank you for the reply. 

In this instance I am looking for indicators that the source table is incomplete.  Where I believe this to be the case I want to cancel the reload process entirely and keep the last loaded data.

There was reference to using Error Codes to trigger an exit without save and I was hoping someone had an example like that.

Cheers,

John.

[#10]

I see.  That does sound like a neater solution if you have multiple tables to check and load.