TechTip: A Way to Capture SQL Statements

SQL
Typography
  • Smaller Small Medium Big Bigger
  • Default Helvetica Segoe Georgia Times
For anyone in the IS/IT departments, SQL can be a very useful and productive tool. However, it can be a dangerous and untraceable process as well. We have found a trick that is very handy for monitoring and troubleshooting data integrity issues.

One of the most common methods of using SQL is by using the STRSQL command. We have modified this command to call our own CL prior to execution of the "real" STRSQL command.

To use this utility, you must have library QUSRSYS defined above QSYS in your system library list. You must create a STRSQL command in QUSRSYS that points to the program CUCSTRSQL, shown in Figure 1.

 

/*------------------------------------------------------------------*
/* COMMAND.....: STRSQL              WRAPPER AROUND STRSQL COMMAND  *
/* EXECUTES....: CUCSTRSQL                                          *
/*                                   1- LOG USER ?                  *
/* PROGRAMMER..: DAVE BURT           2- LIMIT TIME TO 200 SECONDS   *
/* WRITTEN.....:  11/19/01                                          *
/*                                                                  *
/* DESCRIPTION:                                                     *
/*                                                                  *
/*------------------------------------------------------------------*
                                                                     
             CMD        PROMPT('START SQL WITH WRAPPER')             

/*------------------------------------------------------------------*/ 
/* PROGRAM.....: CUCSTRSQL           START SQL (STRSQL) WITH LIMITS */ 
/* PROGRAMMER..: DAVE BURT           AND LOGGING                    */ 
/* WRITTEN.....:  11/19/01                                          */ 
/*                                                                  */ 
/* CALLED BY...: QUSRSYS/STRSQL                                     */ 
/*                                                                  */ 
/*------------------------------------------------------------------*/

PGM                                                   
             DCL        VAR(&USER) TYPE(*CHAR) LEN(10)
             DCL        VAR(&NAME) TYPE(*CHAR) LEN(50)

 /* GET USER INFORMATION                      */      
             RTVJOBA    USER(&USER)
             RTVUSRPRF  TEXT(&NAME)

/* OVERRIDE MESSAGE CHECKING AND SQL   LIMIT */                      
            CALL       PGM(CUCJOBCTL) PARM('S')                      
            MONMSG CPF0000                                           
                                                                     
/* SHOW MESSAGE */                                                   
            SHOWAMSG   MESSAGE('SQL processing time will be limited +
                         to 200 seconds.')                           

/* LOG START */                                                
            CALL       PGM(CURSQLLOG) PARM(&USER &NAME 'START')
            MONMSG CPF0000                                     
            CALL       PGM(CUCDBMON ) PARM('S')                
            MONMSG CPF0000                                     
                                                               
/* REAL SQL  */                                                
            ?          QSYS/STRSQL                             
            MONMSG CPF0000                                     

/* LOG STOP  */                                                
            CALL       PGM(CURSQLLOG) PARM(&USER &NAME 'STOP ')
            MONMSG CPF0000                                     
            CALL       PGM(CUCDBMON ) PARM('E')                
            MONMSG CPF0000
                                                               
/* BACK TO NORMAL */                                           
            CALL       PGM(CUCJOBCTL) PARM('N')
            MONMSG CPF0000

ENDOFPGM:
ENDPGM

Figure 1: Program CUCSTRSQL

As you can see, we call several programs within this CL. You may choose to include or exclude any of these programs in your copy.

The first program called (CUCJOBCTL – SQL Limit) defines a limitation that we set using the Change Query Attributes (CHGQRYA) command to limit the SQL and query processing to 200 seconds. Because we had a large number of people querying the database, the system was being tasked with large statement returns. This limitation helped performance.

/*------------------------------------------------------------------*/ 
/* PROGRAM.....: CUCJOBCTL                                          */
/* PROGRAMMER..: DAVE BURT                                          */ 
/* WRITTEN.....:  11/20/01                                          */ 
/*                                                                  */ 
/*                                                                  */ 
/*                                                                  */ 
/*------------------------------------------------------------------*/
PGM        PARM(&ACTION)                               
                                                       
             DCL        VAR(&ACTION) TYPE(*CHAR) LEN(1)
                                                       
             IF         COND(&ACTION = 'S') THEN(DO)   
             CHGQRYA    QRYTIMLMT(200)                 
             CHGJOB     INQMSGRPY(*SYSRPYL)            
             ENDDO                                     
                                                       
             ELSE CMD(DO)                              
             CHGQRYA    QRYTIMLMT(*NOMAX)              
             CHGJOB     INQMSGRPY(*RQD)                
             ENDDO                                     
ENDPGM                                                 
****************** End of data ************************

Figure 2: Program CUCJOBCTL

The next program called, CURSQLLOG, logs the SQL statement that is executed. This program logs only the statement, not the returned data. The statement is written to a file that can be queried later for auditing purposes.

************** Beginning of data ************************************
*-------------------------------------------------------------------*
* Program....: CURSQLLOG        Write Start/Stop Records for SQL    *
* Programmer.: Dave Burt        LOG                                 *
* Written....: 11/21/01                                             *
*                                                                   *
* Called by..: CUCSTRSQL                                            *
*-------------------------------------------------------------------*

*----------------------------------------------------------------*   
* Files                                                              
*----------------------------------------------------------------*   
cupsqllog o  a e             disk                                    

*----------------------------------------------------------------*
* Fields                                                          
*----------------------------------------------------------------*
 pgmUser         s             10a                                
 name            s             50a                                
 action          s             10a                                
                                                                  
 today           s              6s 0                              
 now             s              6s 0                              
 timedate        s             12s 0                              
 dateYMD         s               D   datfmt(*YMD)                 
                sds                                               
                                                                  
                                                                  
*----------------------------------------------------------------*
* Main Routine                                                    
*----------------------------------------------------------------*
     *entry        plist                                          
                   parm                    pgmUser
timedate        s             12s 0                              
 dateYMD         s               D   datfmt(*YMD)                 
                sds                                               
                                                                  
*----------------------------------------------------------------*
* Main Routine                                                    
*----------------------------------------------------------------*
     *entry        plist                                          
                   parm                    pgmUser                
                   parm                    name                   
                   parm                    action                 
                                                                  
                   time                    timedate               
                   move      timedate      today                  
                                                                  
     *MDY          move      today         dateYMD                
                   move      dateYMD       today                  
                                                                  
                   movel     timedate      now

                   eval      squser   = pgmUser
                   eval      sqname   = name   
                   eval      sqdate   = today  
                   eval      sqtime   = now    
                   eval      sqaction = action 
                   eval      sqsql    = action 
                   write     sqlrcd            
                                               
                   eval      *inlr = *on 
***************** End of data *****************

Figure 3: Program CURSQLLOG

The next CL program, CUCDBMON, runs the database monitor as *OWNER (since users might not have the rights needed to run this monitoring program):

*************** Beginning of data *************************************
/*------------------------------------------------------------------*/ 
/* PROGRAM.....: CUCDBMON            START OR STOP DATABASE MONITOR */ 
/* PROGRAMMER..: DAVE BURT           USING *OWNER AUTORITY          */ 
/* WRITTEN.....:  08/19/99                                          */ 
/*                                                                  */ 
/* DESCRIPTION:                                                     */ 
/*                                                                  */ 
/*                                                                  */ 
/*------------------------------------------------------------------*/ 
                                                                       
PGM        PARM(&ACTION)                                               
                                                                       
             DCL        VAR(&ACTION) TYPE(*CHAR) LEN(1)                
                                                                       
             CALL       PGM(CUCDBMON2) PARM(&ACTION)                   
                                                                       
ENDPGM                                                                 
****************** End of data ****************************************

Figure 4: Program CUCDBMON

The CUCDBMON2 program runs the monitoring portion of the capture process. It returns the data to file DBMON.

*************** Beginning of data ************************************
/*------------------------------------------------------------------*/
/* PROGRAM.....: CUCDBMON2           START OR STOP DATABASE MONITOR */
/* PROGRAMMER..: DAVE BURT           USING *OWNER AUTORITY          */
/* WRITTEN.....:  08/19/99                                          */
/*                                                                  */
/* DESCRIPTION:                                                     */
/*                                                                  */
/*                                                                  */
/*------------------------------------------------------------------*/
                                                                      
PGM        PARM(&ACTION)                                              
                                                                      
             DCL        VAR(&ACTION) TYPE(*CHAR) LEN(1)               
             DCL        VAR(&USER  ) TYPE(*CHAR) LEN(10)              
                                                                      
             RTVJOBA    USER(&USER)                                   
/* START */                                                           
             IF         COND(&ACTION = 'S') THEN(DO)                  
             STRDBMON   OUTFILE(CUSTOM/DBMON) OUTMBR(&USER)
ENDDO                                                   
                                                                     
/* STOP AND CALL LOG PROGRAM */                                      
                                                                     
             ELSE       CMD(DO)                                      
             ENDDBMON                                                
             OVRDBF     FILE(DBMON) TOFILE(CUSTOM/DBMON) MBR(&USER) +
                          OVRSCOPE(*JOB)                             
             CALL       PGM(CURDBMON) PARM(&USER)                    
             DLTOVR     FILE(DBMON) LVL(*JOB)                        
             ENDDO                                                   
                                                                     
ENDPGM                                                               
****************** End of data **************************************

Figure 5: Program CUCDBMON2

The program call from CURDBMON extracts the log records that were captured in the monitor program.

************** Beginning of data ************************************
*-------------------------------------------------------------------*
* Program....: CURDBMON         Extract log records from Start      *
* Programmer.: Dave Burt        Database Monitor.                   *
* Written....: 11/21/01                                             *
*                                                                   *
*                                                                   *
* Called by..: CUCDBMON2                                            *
*                                                                   *
* COMPILE WITH ALWNULL(*YES)                                         
*                                                                   *
* Modifications:                                                    *
*                                                                   *
*-------------------------------------------------------------------*
                                                                     
*----------------------------------------------------------------*   
* Files                                                              
*----------------------------------------------------------------*   
dbmon     if   e             disk                                    
cupsqllog if a e           k disk

                                                                  
*----------------------------------------------------------------*
* Fields                                                          
*----------------------------------------------------------------*
 user            s             10a                                
                                                                  
 uCase           c                   const('ABCDEFGHIJKLMNOPQR-   
                                     STUVWXYZ')                   
                                                                  
 lCase           c                   const('abcdefghijklmnopqr-   
                                     stuvwxyz')                   
                                                                  
 yes             c                   const('Y')                   
 no              c                   const('N')                   
                                                                  
 vFlag           s              1a                                
 text            s           1002a                                
                                                                  
 zDate           s              6s 0
zTime           s              6s 0                              
 sTime           s              6s 0                              
 dateYMD         s               d   datfmt(*YMD)                 
 timeHMS         s               t   timfmt(*HMS)                 
                                                                  
                                                                  
*----------------------------------------------------------------*
* Main Routine                                                    
*----------------------------------------------------------------*
     *entry        plist                                          
                   parm                    user                   
                                                                  
     user          chain     cupsqllog                            
                   read      dbmon                                
                                                                  
                   dow       not %eof                             
                   exsr      filter                               
                                                                  
                   if        vFlag = yes                          
                   exsr      wrtRcd
endif                                            
                                                                    
                   read      dbmon                                  
                   enddo                                            
*                                                                   
** delete records older than 30 days                                
*                                                                   
                   call      'CURDBMON2'                          99
*                                                                   
** End program                                                      
*                                                                   
                   eval      *inlr = *on                            
                                                                    
*-----------------------------------------------------------        
     filter        begsr                                            
*-----------------------------------------------------------        
                                                                    
                   eval      vFlag = no                             
                   eval      text = *blanks                         
     lCase:uCase   xlate     qq1000        text
*                                                                     
** Select                                                             
*                                                                     
     'SELECT':6    scan      text                                   50
                                                                      
                   if        *in50 = *on                              
                   eval      sqaction='SELECT'                        
                   eval      vFlag = yes                              
                   goto      filterx                                  
                   endif                                              
*                                                                     
** INSERT                                                             
*                                                                     
     'INSERT':6    scan      text                                   50
                                                                      
                   if        *in50 = *on                              
                   eval      sqaction='INSERT'                        
                   eval      vFlag = yes                              
                   goto      filterx                                  
                   endif
*                                                                     
** UPDATE                                                             
*                                                                     
     'UPDATE':6    scan      text                                   50
                                                                      
                   if        *in50 = *on                              
                   eval      sqaction='UPDATE'                        
                   eval      vFlag = yes                              
                   goto      filterx                                  
                   endif                                              
*                                                                     
** DELETE                                                             
*                                                                     
     'DELETE':6    scan      text                                   50
                                                                      
                   if        *in50 = *on                              
                   eval      sqaction='DELETE'                        
                   eval      vFlag = yes                              
                   goto      filterx                                  
                   endif

     filterx       endsr                                    
                                                            
*-----------------------------------------------------------
     wrtRcd        begsr                                    
*-----------------------------------------------------------
                                                            
                   move      qqtime        dateYMD          
                   move      qqtime        timeHMS          
                   move      dateYMD       zDate            
                   move      timeHMs       ztime            
                   eval      sqdate = zDate                 
                   eval      sqtime = zTime                 
                   eval      sqsql  = *blanks               
                   movel     qq1000        sqsql            
                                                            
                   if        zTime <> sTime                 
                   write     sqlrcd                         
                   endif                                    

eval      sTime = zTime
                                          
     wrtRcdx       endsr                  
***************** End of data ************

Figure 6: Program CURDBMON

The initial CL then cycles through the logging and monitoring programs (with different parameters).
This is a handy feature once it is in place, and a menu can be created to help administrators utilize the logged information. It is also a better response to the missing SQL trail than removing SQL ability altogether.

The CURDBMON2 program is called to purge the SQL log. You can modify the code to fit whatever timeframe suits your needs.


 *-------------------------------------------------------------------*
 * Program....: CURDBMON2        Delete  log records from Start      *
 * Programmer.: Dave Burt        Database Monitor.                   *
 * Written....: 11/21/01                                             *
 *                                                                   *
 *                                                                   *
 * Called by..: CURDBMON                                             *
 *                                                                   *
 *                                                                   *
 * Modifications:                                                    *
 *                                                                   *
 *-------------------------------------------------------------------*
                                                                      
 *----------------------------------------------------------------*   
 * Files                                                              
 *----------------------------------------------------------------*   
Fculsqllog uf   e           k disk                                    
                                                                      
                                                                      
 *----------------------------------------------------------------*
* Fields                                                          
 *----------------------------------------------------------------*
D timedate        s             12s 0                              
D today           s              6s 0                              
D prgDate         s              6s 0                              
D dateYMD         s               d   datfmt(*YMD)                 
D dateMDY         s               d   datfmt(*MDY)                 
                                                                   
                                                                   
 *----------------------------------------------------------------*
 * Main Routine                                                    
 *----------------------------------------------------------------*
                                                                   
C                   time                    timedate               
C                   move      timedate      today                  
C     *mdy          move      today         dateMDY                
C     dateMDY       subdur    1:*Y          dateYMD                
C                   move      dateYMD       prgDate                
                                                                   
C                   read      culsqllog
C                   dow       not %eof  and sqdate < prgDate  
C                   delete    sqlrcd                          
C                   read      culsqllog                       
C                   enddo                                     
 *                                                            
 ** End program                                               
 *                                                            
C                   eval      *inlr = *on

Figure 7: Program CURDBMON2

This utility requires two files, DBMON and CUPSQLLOG. The DDS for DBMON can be obtained by issuing the Start Database Monitor (STRDBMON) command to an outfile. Below you will find the DDS for CUPSQLLOG.

*--------------------------------------------------------
 * FILE......: CUPSQLLOG                LOG OF SQL USAGE  
 * PROGRAMMER: DAVE BURT                                  
 * DATE......: 11/19/01                                   
 *                                                        
 *--------------------------------------------------------
                                                          
A          R SQLRCD                                       
                                                          
A            SQUSER        10A                            
A            SQNAME        50A                            
A            SQDATE         6S 0                          
A            SQTIME         6S 0                          
A            SQACTION      10A                            
A            SQSQL        256A                            
                                                          
A          K SQUSER                                       
A          K SQDATE                                       
A          K SQTIME

Figure 8: Program CUPSQLLOG

The zipped save file logsqlsavf.zip accompanies this document. It contains all the source for this utility, minus the SHOWAMSG command. Substitute the SNDMSG or SNDBRKMSG command for SHOWAMSG. The save file is set to V4R4.

Unzip and then FTP the save file from your PC to your AS/400. Use the following command:

RSTOBJ OBJ(LOGSQL) OBJTYPE(*FILE) DEV(*SAVF) SAVF(yoursavefilename)
RSTLIB(yourlibraryname)


Kristian Bryant and David Burt are iSeries 400 professionals. Kristian is a Systems Administrator. Dave Burt is a programmer on the iSeries with 15 years experience in RPG.

BLOG COMMENTS POWERED BY DISQUS

LATEST COMMENTS

Support MC Press Online

$

Book Reviews

Resource Center

  •  

  • LANSA Business users want new applications now. Market and regulatory pressures require faster application updates and delivery into production. Your IBM i developers may be approaching retirement, and you see no sure way to fill their positions with experienced developers. In addition, you may be caught between maintaining your existing applications and the uncertainty of moving to something new.

  • The MC Resource Centers bring you the widest selection of white papers, trial software, and on-demand webcasts for you to choose from. >> Review the list of White Papers, Trial Software or On-Demand Webcast at the MC Press Resource Center. >> Add the items to yru Cart and complet he checkout process and submit

  • SB Profound WC 5536Join us for this hour-long webcast that will explore:

  • Fortra IT managers hoping to find new IBM i talent are discovering that the pool of experienced RPG programmers and operators or administrators with intimate knowledge of the operating system and the applications that run on it is small. This begs the question: How will you manage the platform that supports such a big part of your business? This guide offers strategies and software suggestions to help you plan IT staffing and resources and smooth the transition after your AS/400 talent retires. Read on to learn: