How to debug a batch job in AS400 steps : Trick to debug a batch job by using ILE debugger

<div dir="ltr" style="text-align: left;" trbidi="on"><h2 style="text-align: left;"><span face="'Trebuchet MS', sans-serif" style="font-size: large;"><b>How to debug a batch job in AS400 steps : Trick to debug a batch job by using ILE debugger</b></span></h2><div class="MsoNormal"><span style="font-size: large;"><b><span face="'Trebuchet MS', sans-serif"><br /></span></b></span></div><div class="MsoNormal"><span style="font-size: large;"><b><span face="'Trebuchet MS', sans-serif">Q. </span></b><span face=""Trebuchet MS","sans-serif"">Your "RPG for RPG Programmers" presentation covered the ILE debugger for interactive jobs. But I need to debug a batch program. Do I need a different debugger?<br /><br /><b>A.</b> No. You can use the same ILE debugger to debug interactive or batch jobs, written in ILE or OPM languages. But there are a few extra steps to get the debugger started. Here's a cheat sheet: <o:p></o:p></span></span></div><span style="font-size: large;"><br /></span><ol start="1" type="1"><li class="MsoNormal"><span face=""Trebuchet MS","sans-serif"" style="font-size: large;">SBMJOB ... HOLD(*YES) <o:p></o:p></span></li><li class="MsoNormal"><span face=""Trebuchet MS","sans-serif"" style="font-size: large;">STRSRVJOB JOB(jobnbr/user/jobnam) <o:p></o:p></span></li><li class="MsoNormal"><span face=""Trebuchet MS","sans-serif"" style="font-size: large;">STRDBG <o:p></o:p></span></li><ul type="circle"><li class="MsoNormal"><span face=""Trebuchet MS","sans-serif"" style="font-size: large;">When source is displayed, press F12<o:p></o:p></span></li></ul><li class="MsoNormal"><span face=""Trebuchet MS","sans-serif"" style="font-size: large;">RLSJOB JOB(jobnbr/user/jobnam) <o:p></o:p></span></li><ul type="circle"><li class="MsoNormal"><span face=""Trebuchet MS","sans-serif"" style="font-size: large;">When Start Serviced Job display appears, press F10<o:p></o:p></span></li></ul><li class="MsoNormal"><span face=""Trebuchet MS","sans-serif"" style="font-size: large;">When command entry display is shown, DSPMODSRC <o:p></o:p></span></li><ul type="circle"><li class="MsoNormal"><span face=""Trebuchet MS","sans-serif"" style="font-size: large;">When source is displayed, set a breakpoint, then press F12 <o:p></o:p></span></li><li class="MsoNormal"><span face=""Trebuchet MS","sans-serif"" style="font-size: large;">When command entry display is shown, press F12<o:p></o:p></span></li></ul><li class="MsoNormal"><span face=""Trebuchet MS","sans-serif"" style="font-size: large;">When Start Serviced Job display reappears, press Enter <o:p></o:p></span></li><ul type="circle"><li class="MsoNormal"><span face=""Trebuchet MS","sans-serif"" style="font-size: large;">Program will stop at breakpoint, and can be debugged interactively<o:p></o:p></span></li></ul><li class="MsoNormal"><span face=""Trebuchet MS","sans-serif"" style="font-size: large;">After serviced job ends <o:p></o:p></span></li><ul type="circle"><li class="MsoNormal"><span face=""Trebuchet MS","sans-serif"" style="font-size: large;">ENDDBG <o:p></o:p></span></li><li class="MsoNormal"><span face=""Trebuchet MS","sans-serif"" style="font-size: large;">ENDSRVJOB<o:p></o:p></span></li></ul></ol><div><span face="Trebuchet MS, sans-serif"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjarlXQLNR-EFgTuY3vIoT-mswVorXUTWZvrpf3fCry0OJwehzQSShGT-2VfZKPwTfxNA-MpXUDp7j4SuoNlGbQqpqLDj7rW7UCz1BeflK_b8YZrEaiNXe74hVijfU-tnVGclFwtporg0I/s1600/how+to+debug+a+batch+job+in+AS400+steps.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjarlXQLNR-EFgTuY3vIoT-mswVorXUTWZvrpf3fCry0OJwehzQSShGT-2VfZKPwTfxNA-MpXUDp7j4SuoNlGbQqpqLDj7rW7UCz1BeflK_b8YZrEaiNXe74hVijfU-tnVGclFwtporg0I/s1600/how+to+debug+a+batch+job+in+AS400+steps.png" /></a></div><div><span face="Trebuchet MS, sans-serif"><br /></span></div><div><span face="Trebuchet MS, sans-serif"><br /></span></div></div>

How to debug a batch job in AS400 steps : Trick to debug a batch job by using ILE debugger

How to debug a batch job in AS400 steps : Trick to debug a batch job by using ILE debuggerQ. Your "RPG for RPG Programmers" presentation covered the ILE debugger for interactive jobs. But I need to de…

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AS-400, AS400 iSeries Interview Questions and Answers, Mainframe AS-400 Interview Questions and Answers

<div dir="ltr" style="text-align: left;" trbidi="on"><h1 style="clear: both; text-align: center;">AS-400, AS400 iSeries Interview Questions and Answers, Mainframe AS-400 Interview Questions and Answers</h1><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh99GujskYpGpbsRDesEEDLKZVIEyL9YD7D0k3ySkqp-uLB-hIGTTA2z54vOSDVuiM0ZABnRo2PQUnjCYYb4UIR_530dFcP-uWz0DILP-NJWXRLKDq7FmtMwzCQqG0Y-S9xcP078pn9SWc/s1600/as400_questions_answers.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh99GujskYpGpbsRDesEEDLKZVIEyL9YD7D0k3ySkqp-uLB-hIGTTA2z54vOSDVuiM0ZABnRo2PQUnjCYYb4UIR_530dFcP-uWz0DILP-NJWXRLKDq7FmtMwzCQqG0Y-S9xcP078pn9SWc/s1600/as400_questions_answers.jpg" width="320" /></a></div><br /><br /><span style="font-size: large;"><br /></span></div><div dir="ltr" style="text-align: left;" trbidi="on"><span style="font-size: large;"><b>What the purpose of the keywords FIFO, LIFO, FCFO?</b><br /><b>Ans: </b>These keywords are used at file level. The purpose of each one is described below:<br /><b>FIFO:</b> The duplicate key records will retrieved in first in first out order.<br /><b>LIFO:</b> The duplicate key records will retrieved in last in first out order.<br /><b>FCFO:</b> The duplicate key records will retrieved in first changed first out order.<br /><br /><b>Why is AS/400 called an Object Oriented Machine ?</b><br /><b>Ans: </b>Everything on the AS/400 system that can be stored or retrieved is contained in an Object. Object exist to make users independent of the implementation techniques used in the machine.<br /><br /><b>What is the difference between regular logical file and join logical file?</b><br /><b>Ans:</b> Regular logical file contains more than one record format.<br />Record format name in regular logical file should be same based on the physical file.</span></div><div style="text-align: left;" trbidi="on"><span style="font-size: large;"><br /><ul style="text-align: left;"><li><span style="font-size: large;">Join logical file contains only one record format.</span></li><li><span style="font-size: large;">Record format name in join logical file should be different.</span></li><li><span style="font-size: large;">Through logical file we can made changes in physical file.</span></li><li><span style="font-size: large;">Through join logical file we can't made changes in physical file.</span></li></ul><br /><b>Distinguish between logical file and physical file?</b><br /><b><br /></b></span></div><div style="text-align: left;" trbidi="on"><span style="font-size: large;"><b>Ans: </b></span></div><div style="text-align: left;" trbidi="on"><ul style="text-align: left;"><li><span style="font-size: large;">Physical file contains only one record format.</span></li><li><span style="font-size: large;">Logical file contains more than one record format.</span></li><li><span style="font-size: large;">Physical file contains actual data.</span></li><li><span style="font-size: large;">Logical file doesn't contains data but it provides view from the physical file.</span></li></ul><span style="font-size: large;"><br /><b>What is field reference file?</b><br /><b>Ans:</b> Field reference file is a file, which contains field definitions and descriptions, and it doesn't have member. Physical contains data derived by the field reference file.<br /><br /><b>What is the difference between access path and Dynamic select?</b><br /><b>Ans:</b> Dynamic select occurs whenever the program reads file. But access path occurs before the file is read (but not necessarily). Because access path maintenance performed on the file.<br /><br /><b>Why would you prefer OPNQRYF than logical file?</b><br /><b>Ans:</b> The main difference is : Logical file creates permanent object on the system. OPNQRYF creates temporary access path.<br /><br /><b>What is the necessary keyword used in a physical file to refer field definitions from the field reference file?</b><br /><b>Ans:</b> REF which is a file level keyword is necessary to define at file level in a physical file. The syntax is as follows: REF(library name/name of the field reference file)<br /><br /><b>What is purpose of declarative statement DEFN?</b><br /><b>Ans:</b> Depends on the factor 1 value it will do two things:<br />* If the factor1is *LIKE then DEFN opcode defines the new field based on the attributes old field. * If the factor 1 is *NAMVAR then DEFN opcodes defines the field as a data area.<br /><br /><b>What is the purpose of SFLNXTCHG keyword in a subfile?</b><br /><b>Ans:</b> Which is a subfile record format keyword. If you perform read on the subfile, the internal indicator MDT (modified data tag) is automatically set off by the system. If you again perform read on the<br />same records, records won't be read. Because internal indicator MDT would be off. Hence you should be explicitly set<br />on the MDT by SFLNXTCHG keyword.<br /><br /><b>What is the difference between Array and Table?</b><br /><b>Ans:</b><br />Array: Array is stored any where in the body of the input records.<br />Table: Table is stored at the beginning of the input records.<br />Array: We can access all the elements in array by specifying the array name.<br />Table: Only one table element can be accessed at a time.<br />Array: Array can be searched randomly.<br />Table: Table can be searched consecutively.<br /><br /><b>What are the different types of access paths maintained on the file?</b><br /><b>Ans:</b><br />Immediate: All the access paths (open and close) associated with a file will be updated whenever changes made to a file.<br />Rebuild- only open access paths will update whenever changes made to the file. Rebuild takes place whenever remaining access paths will be open.<br />Delay : Rebuild will not takes place.<br /><br /><b>What is the purpose of reorganizing the physical file i. e. , RGZPFM?</b><br /><b>Ans:</b> Even if you delete the records in a physical file through the program, still the space used by the deleted records not used by the other purpose. Hence using RGZPFM command we can compress the deleted records space.<br /><br /><b>What is the purpose of CHGPF (Change physical file) command?</b><br /><b>Ans:</b> CHGPF command is used to change the attributes of a physical file. Attributes like<br /><ul style="text-align: left;"><li><span style="font-size: large;">   Maximum number of members</span></li><li><span style="font-size: large;">   Member size</span></li><li><span style="font-size: large;">   Level check enforced</span></li><li><span style="font-size: large;">   Open data path is shared</span></li></ul><br /><br /><br /><b>What are the communication protocols supported by AS/400 ?</b><br /><b>Ans:</b> </span></div><div style="text-align: left;" trbidi="on"><span style="font-size: large;">APPC (Advanced Program to Program Communication)<br />BSCEL(Binary Synchronous Link)<br />ASYNCH(Asynchronous Communication)<br />RETAIL<br />TCP IP<br />FINANCE<br />SNUF SNA Upline facility<br />INTRA Intrasystem communication.<br /><br /><br /><b>What are the different ways of connecting a terminal to a system ?</b><br /><b>Ans:</b> Twinnax, Workstation, ASCII and OS/2 Workstation.<br /><br /><br /><b>How can you identify End of file in CLP program?</b><br /><b>Ans: </b>With the help of MONMSG MSGID(CPF0864) we can identify end of file in clp program.<br /><br /><b>What is the difference between production library and test library ?</b><br /><b>Ans:</b> In debug mode, the files exists in production library not allowed to update.<br />In the other hand, the files exists in test library allowed to update.</span><br /><br /><br /><br /></div>

AS-400, AS400 iSeries Interview Questions and Answers, Mainframe AS-400 Interview Questions and Answers

AS-400, AS400 iSeries Interview Questions and Answers, Mainframe AS-400 Interview Questions and AnswersWhat the purpose of the keywords FIFO, LIFO, FCFO?Ans: These keywords are used at file level. The…

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OS/400 CL Programming : Using the QCMDEXC Program AS 400 CL Commands examples

<div dir="ltr" style="text-align: left;" trbidi="on"><h1 style="text-align: left;">OS/400 CL Programming : Using the QCMDEXC Program AS 400 CL Commands examples </h1><div><br /></div><div><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg7z5GNjrRYzOM5nMFG4rAnoPRoGV2cY5ygI_fgwKUTTSvgI3EJ998ZVz0VdxIJi8dGK-ODd69pWIkleXY2swkcqgbbl6o5E6M_GuC7wLZBP01YXIra_iBQQoQDo1uvDb6OlKiabRHqvsA/s1600/control+language.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg7z5GNjrRYzOM5nMFG4rAnoPRoGV2cY5ygI_fgwKUTTSvgI3EJ998ZVz0VdxIJi8dGK-ODd69pWIkleXY2swkcqgbbl6o5E6M_GuC7wLZBP01YXIra_iBQQoQDo1uvDb6OlKiabRHqvsA/s1600/control+language.jpg" width="320" /></a></div><div><br /></div><div><br /></div><br /><br /><h3><span style="font-size: large;">Using the QCMDEXC Program</span></h3><span style="font-size: large;">QCMDEXC is an IBM-supplied program that runs a single command. It is used to run a command from within a high-level language (HLL) program or from within a CL procedure or program where it is not known at compile time what command is to be run or what parameters are to be used. The QCMDEXC program is called from within your HLL or CL procedure or program and the command it runs is passed to it as a parameter on the CALL command. <br /><br /></span><pre><span style="font-size: large;"> CL or HLL program QCMDEXC<br /> /---------------------------\ /------------------\<br /> | . | | |<br /> | . | /--� | PGM(PARM1 PARM2) | <br /> | . | | | . |<br /> | CALL QCMDEXC(PARM1 PARM2) |----/ | . |<br /> | . | | . |<br /> | . | �-------| RETURN | <br /> | . | | |<br /> \---------------------------/ \------------------/<br /></span></pre><span style="font-size: large;">After the command runs, control returns to your HLL or CL procedure or program. <br />The command is run as if it were not in a program. Therefore, variables cannot be used on the command; values cannot be returned by the command to CL variables; and commands that can only be used in CL procedures or programs cannot be run by the QCMDEXC program. The format of the call to the QCMDEXC program is the following: <br /><br /><br /></span><pre><span style="font-size: large;">CALL PGM(QCMDEXC) PARM(command command-length)<br /></span></pre><span style="font-size: large;">The command you wish to run is entered as a character string on the first parameter. If the command contains blanks, it must be enclosed in apostrophes. The maximum length of the character string is 6000 characters ; delimiters (the apostrophes enclosing the string) are never counted as part of the string. The length specified as the second value on the PARM parameter is the length of the character string passed as the command. Length must be a packed decimal value of length 15 with 5 decimal positions . <br />Thus, if you wish to replace a library list, the call to the QCMDEXC program would look like this: <br /><br /><br /></span><pre><span style="font-size: large;">CALL PGM(QCMDEXC) PARM('CHGLIBL LIBL(QGPL NEWLIB QTEMP)' 31)<br /></span></pre><span style="font-size: large;">This statement could be coded into the HLL or CL program, and when the program runs, the library list would be replaced. Used this way, however, the QCMDEXC program does not provide run-time flexibility. That is accomplished by substituting variables for the constants in the parameter list, and specifying the values for the variables in the call to the HLL or CL program. <br />For instance: <br /><br /></span><pre><span style="font-size: large;">CALL PGM(PGMA) PARM('CHGLIBL...' 3000)<br /> |<br /> |<br /> | /-----------------------------------------\<br /> \---�| PGM PARM(&STRING &LENGTH) /* PGMA */ |<br /> | DCL &STRING *CHAR LEN(3000) | <br /> | DCL &LENGTH *DEC LEN(15 5) |<br /> | . | <br /> | . | /----� QCMDEXC <br /> | . | | /-------------\<br /> | CALL PGM(QCMDEXC) PARM(&STRING &LENGTH)-+--/ | . | <br /> | . �-------------------------------------+---\ | . | <br /> | . | | | . | <br /> | . | | | CHGLIBL... |<br /> | END | | | . | <br /> \-----------------------------------------/ | | . | <br /> \-+-. | <br /> \-------------/<br /></span></pre><span style="font-size: large;">The command length, which is passed to the QCMDEXC program on the second parameter, is the maximum length of the command string being passed. If the command string is passed as a quoted string, the command length is exactly the length of the quoted string. If the command string is passed in a variable, the command length is the length of the CL variable. It is not necessary to reduce the command length to the actual length of the command string in the variable, although it is permissible to do so. <br />The same command could be run using the following CALL command from the CL procedure or program because numeric literals are passed as packed decimal values of length 15 with 5 decimal positions: <br /><br /></span><pre><span style="font-size: large;">CALL QCMDEXC (&STRING 3000)<br /></span></pre><span style="font-size: large;">Not all commands can be run using the QCMDEXC program. The command passed on a call to the QCMDEXC program must be valid within the current environment (interactive or batch) in which the call is being made. The command cannot be one of the following: <br />o       An input stream control command (BCHJOB, ENDBCHJOB, and DATA) <br />o       A command that can be used only in a CL program <br /><br /><br />To find the environment in which the command can be run, look at the syntax diagram for the command. The small box in the upper right corner of the diagram indicates the environment in which the command can be run. For example, JOB: I indicates that the command can be run interactively; JOB: B indicates that the command can be run in a batch job; Exec indicates that the command can be run with QCMDEXC. <br />You can precede the CL command with a question mark (?) to request prompting, or use selective prompting, when you call QCMDEXC in an interactive job. <br />If an error is detected while a command is being processed through the QCMDEXC program, an escape message is sent. You can monitor for this escape message in your CL procedure or program using the Monitor Message (MONMSG) command.<br /><br />If a syntax error is detected, message CPF0006 is sent. If an error is detected during the processing of a command, any escape message sent by the command is returned by the QCMDEXC program. You monitor for messages from commands run through the QCMDEXC program in the same way you monitor for messages from commands contained in CL procedures and programs. </span><br /> <br /><br /></div>

OS/400 CL Programming : Using the QCMDEXC Program AS 400 CL Commands examples

OS/400 CL Programming : Using the QCMDEXC Program AS 400 CL Commands examples Using the QCMDEXC ProgramQCMDEXC is an IBM-supplied program that runs a single command. It is used to run a command from…

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Advantages of DB2 CLI over embedded SQL

<div dir="ltr" style="text-align: left;" trbidi="on"><h1 style="text-align: justify;">Advantages of DB2 CLI over embedded SQL</h1><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgREk6eMWPtvXFPtVPVdshT7Iu_fPEbrZIDyaja-mGL7T6CQ1QC-HvWUFgK0n3O78dqb-d3JEdX37lvPMYBVmaKTX3DlNE3nSRREoZNjSJjLBPfnNeLb_ASPa_nq1XejRBp_TUsnTzpjAc/s1600/DB2-concepts+at+www.topnaukrialert.com.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="226" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgREk6eMWPtvXFPtVPVdshT7Iu_fPEbrZIDyaja-mGL7T6CQ1QC-HvWUFgK0n3O78dqb-d3JEdX37lvPMYBVmaKTX3DlNE3nSRREoZNjSJjLBPfnNeLb_ASPa_nq1XejRBp_TUsnTzpjAc/s1600/DB2-concepts+at+www.topnaukrialert.com.jpg" width="320" /></a></div><div><br /></div><div style="text-align: justify;"><span style="font-size: large;"><a href="https://www.blogger.com/null" name="idx301"></a><a href="https://www.blogger.com/null" name="idx302"></a>The DB2 CLI interface has several key advantages over embedded SQL. </span></div><div style="text-align: justify;"><span style="font-size: large;"><br /></span></div><ul type="disc"><li class="MsoNormal" style="mso-list: l1 level1 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list .5in; text-align: justify;"><span style="font-size: large;">It is ideally suited for a client-server environment, in which the target database is not known when the application is built. It provides a consistent interface for executing SQL statements, regardless of which database server the application is connected to. </span></li><li class="MsoNormal" style="mso-list: l1 level1 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list .5in; text-align: justify;"><span style="font-size: large;">It increases the portability of applications by removing the dependence on pre-compilers. Applications are distributed not as embedded SQL source code which must be preprocessed for each database product, but as compiled applications or run time libraries. </span></li><li class="MsoNormal" style="mso-list: l1 level1 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list .5in; text-align: justify;"><span style="font-size: large;">Individual DB2 CLI applications do not need to be bound to each database, only bind files shipped with DB2 CLI need to be bound once for all DB2 CLI applications. This can significantly reduce the amount of management required for the application once it is in general use. </span></li><li class="MsoNormal" style="mso-list: l1 level1 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list .5in; text-align: justify;"><span style="font-size: large;">DB2 CLI applications can connect to multiple databases, including multiple connections to the same database, all from the same application. Each connection has its own commit scope. This is much simpler using CLI than using embedded SQL where the application must make use of multi-threading to achieve the same result. </span></li><li class="MsoNormal" style="mso-list: l1 level1 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list .5in; text-align: justify;"><span style="font-size: large;">DB2 CLI eliminates the need for application controlled, often complex data areas, such as the SQLDA and SQLCA, typically associated with embedded SQL applications. Instead, DB2 CLI allocates and controls the necessary data structures, and provides a <span class="italic">handle</span> for the application to reference them. </span></li><li class="MsoNormal" style="mso-list: l1 level1 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list .5in; text-align: justify;"><span style="font-size: large;">DB2 CLI enables the development of multi-threaded thread-safe applications where each thread can have its own connection and a separate commit scope from the rest. DB2 CLI achieves this by eliminating the data areas described above, and associating all such data structures that are accessible to the application with a specific handle. Unlike embedded SQL, a multi-threaded CLI application does not need to call any of the context management DB2^(R) APIs; this is handled by the DB2 CLI driver automatically. </span></li><li class="MsoNormal" style="mso-list: l1 level1 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list .5in; text-align: justify;"><span style="font-size: large;">DB2 CLI provides enhanced parameter input and fetching capability, allowing arrays of data to be specified on input, retrieving multiple rows of a result set directly into an array, and executing statements that generate multiple result sets. </span></li><li class="MsoNormal" style="mso-list: l1 level1 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list .5in; text-align: justify;"><span style="font-size: large;">DB2 CLI provides a consistent interface to query catalog (Tables, Columns, Foreign Keys, Primary Keys, etc.) information contained in the various DBMS catalog tables. The result sets returned are consistent across DBMSs. This shields the application from catalog changes across releases of database servers, as well as catalog differences amongst different database servers; thereby saving applications from writing version specific and server specific catalog queries. </span></li><li class="MsoNormal" style="mso-list: l1 level1 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list .5in; text-align: justify;"><span style="font-size: large;">Extended data conversion is also provided by DB2 CLI, requiring less application code when converting information between various SQL and C data types. </span></li><li class="MsoNormal" style="mso-list: l1 level1 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list .5in; text-align: justify;"><span style="font-size: large;">DB2 CLI incorporates both the ODBC and X/Open CLI functions, both of which are accepted industry specifications. DB2 CLI is also aligned with the ISO CLI standard. Knowledge that application developers invest in these specifications can be applied directly to DB2 CLI development, and vice versa. This interface is intuitive to grasp for those programmers who are familiar with function libraries but know little about product specific methods of embedding SQL statements into a host language. </span></li><li class="MsoNormal" style="mso-list: l1 level1 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list .5in; text-align: justify;"><span style="font-size: large;">DB2 CLI provides the ability to retrieve multiple rows and result sets generated from a stored procedure residing on a DB2 Universal Database (or DB2 Universal Database for z/OS and OS/390 version 5 or later) server. However, note that this capability exists for Version 5 DB2 Universal Database clients using embedded SQL if the stored procedure resides on a server accessible from a DataJoiner^(R) Version 2 server. </span></li><li class="MsoNormal" style="mso-list: l1 level1 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list .5in; text-align: justify;"><span style="font-size: large;">DB2 CLI offers more extensive support for scrollable cursors. With scrollable cursors, you can scroll through a cursor as follows: </span></li><ul type="circle"><li class="MsoNormal" style="mso-list: l1 level2 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list 1.0in; text-align: justify;"><span style="font-size: large;">Forward by one or more rows </span></li><li class="MsoNormal" style="mso-list: l1 level2 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list 1.0in; text-align: justify;"><span style="font-size: large;">Backward by one or more rows </span></li><li class="MsoNormal" style="mso-list: l1 level2 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list 1.0in; text-align: justify;"><span style="font-size: large;">From the first row by one or more rows </span></li><li class="MsoNormal" style="mso-list: l1 level2 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list 1.0in; text-align: justify;"><span style="font-size: large;">From the last row by one or more rows. </span></li></ul></ul><div class="MsoNormal" style="margin-left: 0.5in; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; text-align: justify;"><span style="font-size: large;">Scrollable cursors can be used in conjunction with array output. You can declare an updatable cursor as scrollable then move forward or backward through the result set by one or more rows. You can also fetch rows by specifying an offset from: </span></div><ul type="disc"> <ul type="circle"><li class="MsoNormal" style="mso-list: l1 level2 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list 1.0in; text-align: justify;"><span style="font-size: large;">The current row </span></li><li class="MsoNormal" style="mso-list: l1 level2 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list 1.0in; text-align: justify;"><span style="font-size: large;">The beginning or end of the result set </span></li><li class="MsoNormal" style="mso-list: l1 level2 lfo1; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list 1.0in; text-align: justify;"><span style="font-size: large;">A specific row you have previously set with a bookmark. </span></li></ul></ul><div class="MsoNormal" style="text-align: justify;"><span style="font-size: large;"><br /></span></div><div class="MsoNormal" style="text-align: justify;"><span style="font-size: large;"><br /></span></div><div class="MsoNormal" style="text-align: justify;"><span style="font-size: large;"><br /></span></div><div class="MsoNormal" style="text-align: justify;"><span style="font-size: large;"><br /></span></div><h3 style="text-align: justify;"><span style="font-size: large;">When to use DB2 CLI or embedded SQL </span></h3><div style="text-align: justify;"><span style="font-size: large;"><a href="https://www.blogger.com/null" name="idx303"></a><a href="https://www.blogger.com/null" name="idx304"></a>Which interface you choose depends on your application. </span></div><div style="text-align: justify;"><span style="font-size: large;">DB2 CLI is ideally suited for query-based graphical user interface (GUI) applications that require portability. The advantages listed above, may make using DB2 CLI seem like the obvious choice for any application. There is however, one factor that must be considered, the comparison between static and dynamic SQL. It is much easier to use static SQL in embedded applications. </span></div><div style="text-align: justify;"><span style="font-size: large;">Static SQL has several advantages: </span></div><ul type="disc"><li class="MsoNormal" style="mso-list: l0 level1 lfo2; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list .5in; text-align: justify;"><span style="font-size: large;">Performance </span></li></ul><div style="margin-left: 0.5in; text-align: justify;"><span style="font-size: large;">Dynamic SQL is prepared at run time, static SQL is prepared at precompile time. As well as requiring more processing, the preparation step may incur additional network-traffic at run time. The additional network traffic can be avoided if the DB2 CLI application makes use of deferred prepare (which is the default behaviour). </span></div><div style="margin-left: 0.5in; text-align: justify;"><span style="font-size: large;">It is important to note that static SQL will not always have better performance than dynamic SQL. Dynamic SQL is prepared at runtime and uses the database statistics available at that time, whereas static SQL makes use of database statistics available at BIND time. Dynamic SQL can make use of changes to the database, such as new indexes, to choose the optimal access plan, resulting in potentially better performance than the same SQL executed as static SQL. In addition, pre compilation of dynamic SQL statements can be avoided if they are cached. </span></div><ul type="disc"><li class="MsoNormal" style="mso-list: l0 level1 lfo2; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list .5in; text-align: justify;"><span style="font-size: large;">Encapsulation and Security </span></li></ul><div style="margin-left: 0.5in; text-align: justify;"><span style="font-size: large;">In static SQL, the authorizations to access objects (such as a table, view) are associated with a package and are validated at package binding time. This means that database administrators need only to grant execute on a particular package to a set of users (thus encapsulating their privileges in the package) without having to grant them explicit access to each database object. In dynamic SQL, the authorizations are validated at run time on a per statement basis; therefore, users must be granted explicit access to each database object. This permits these users access to parts of the object that they do not have a need to access. .</span></div><div style="margin-left: 0.5in; text-align: justify;"><span style="font-size: large;"><br /></span></div><div style="margin-left: 0.5in; text-align: justify;"><span style="font-size: large;"><br /></span></div><div style="margin-left: 0.5in; text-align: justify;"><span style="font-size: large;"><br /></span></div><ul type="disc"><li class="MsoNormal" style="mso-list: l0 level1 lfo2; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list .5in; text-align: justify;"><span style="font-size: large;">Embedded SQL is supported in languages other than C or C++. </span></li><li class="MsoNormal" style="mso-list: l0 level1 lfo2; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; tab-stops: list .5in; text-align: justify;"><span style="font-size: large;">For fixed query selects, embedded SQL is simpler. </span></li></ul><div style="text-align: justify;"><span style="font-size: large;">If an application requires the advantages of both interfaces, it is possible to make use of static SQL within a DB2 CLI application by creating a stored procedure that contains the static SQL. The stored procedure is called from within a DB2 CLI application and is executed on the server. Once the stored procedure is created, any DB2 CLI or ODBC application can call it. </span></div><div style="text-align: justify;"><span style="font-size: large;">It is also possible to write a mixed application that uses both DB2 CLI and embedded SQL, taking advantage of their respective benefits. In this case, DB2 CLI is used to provide the base application, with key modules written using static SQL for performance or security reasons. This complicates the application design, and should only be used if stored procedures do not meet the applications requirements. </span></div><span style="font-size: large;"><br /></span><div style="text-align: justify;"><span style="font-size: large;">Ultimately, the decision on when to use each interface, will be based on individual preferences and previous experience rather than on any one factor. </span></div></div>

Advantages of DB2 CLI over embedded SQL

Advantages of DB2 CLI over embedded SQLThe DB2 CLI interface has several key advantages over embedded SQL. It is ideally suited for a client-server environment, in which the target database …

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