| SQL, DB2/2 and 32-bit COBOL | Interface to Informix DBMS | |
COBSQL is an integrated preprocessor designed to work with COBOL precompilers supplied by relational database vendors. It is intended for use with:
You should use COBSQL if you are already using either of these precompilers with an earlier version of a Micro Focus COBOL product and want to migrate your application(s) to Server Express, or if you are creating applications that will be deployed on UNIX platforms and need to access either Oracle or Sybase relational databases.
For any other type of embedded SQL application development, we recommend that you use OpenESQL.
Notes :
You can access the SQL functions offered by the Oracle, Sybase or Informix Database Management System (DBMS) by embedding SQL statements within your COBOL program in the form:
EXEC SQL SQL statement END-EXEC
and then using the Oracle, Sybase or Informix precompiler to process the embedded SQL before passing the program to the COBOL Compiler. The database precompiler replaces embedded SQL statements with the appropriate calls to database services. Other additions are made to the source code to bind COBOL host variables to the SQL variable names known to the database system.
The advantage of embedding SQL in this way is that you do not need to know the format of individual database routine calls. The disadvantage is that the source code that you see when you animate your program is that output by the precompiler and not the original embedded SQL. You can overcome this disadvantage by using COBSQL.
COBSQL provides an integrated interface between Micro Focus COBOL and the third-party standalone precompiler, enabling you to animate a program containing EXEC SQL statements and display your original source code rather than the code produced by the precompiler.
This chapter shows you how you can use COBSQL in conjunction with either the Oracle, Sybase or Informix precompiler to compile and animate your programs.
To use COBSQL, specify the PREPROCESS"COBSQL" Compiler directive when you compile your program. All directives following it are passed from the Compiler to COBSQL. You can specify Compiler directives by using $SET statements in your program or via the cob command line.
To terminate the directives to be passed to COBSQL, you must use the ENDP COBOL directive. You can do this by making the following changes to the directives:
C"preprocess(Cobsql) csqltype=oracle end-c comp5=yes endp"
When using Server Express, END-C and ENDP have the following effect:
You specify directives to COBSQL as if they were Compiler directives, but you must put them after the directive PREPROCESS"COBSQL".
It is also possible to add the Cobsql directives to the standard Server Express directives file cobol.dir.
Notes:
Alternatively, you can put COBSQL and precompiler directives in a file, cobsql.dir. This file should reside either in the current directory or in a directory specified in $COBDIR. COBSQL searches the current directory and then along the COBDIR path for a cobsql.dir file. Once COBSQL finds a cobsql.dir file, it stops searching. So, if you have a cobsql.dir file in the current directory, the COBDIR path is not searched.
Notes:
COBSQL processes cobsql.dir first and then any directives specified via the cob command line.
A number of the directives can be reversed by placing NO in front of them, for example, DISPLAY can be reversed using NODISPLAY. All the directives in the lists below that can have NO placed in front of them are marked with an asterisk. By default, the NO version of a directive is set.
You can specify shortened versions of some of the directives. If applicable, the shortened version of a directive is shown in the lists below, immediately after the full length version.
Some directives can be passed to COBSQL by the COBOL Compiler (see the section COBOL Directives below), removing the need to specify common directives more than once. Directives that can be retrieved from the COBOL Compiler are processed before COBSQL directives.
For example, in the following command line:
cob -V -k testprog.pco -C"p(cobsql) csqlt==ora makesyn end-c xref==yes mode==ansi endp omf(gnt) list()"
end-c, are csqlt=ora
and makesyn.endp,
are xref=yes and mode=ansi. omf(gnt) and list().
| COBSQLTYPE CSQLT |
Specifies which precompiler to use (ORACLE, SYBASE or INFORMIX-NEW); for example, COBSQLTYPE=ORACLE . |
| CSTOP* CSP |
Forces COBSQL to load the stop run module that performs a rollback if the application terminates abnormally. |
| DEBUGFILE* DEB |
Creates a debug (.deb) file. |
| DISPLAY* DIS |
Displays precompiler statistics. Should only be used when initially verifying that COBSQL is correctly calling the standalone precompiler. |
| END-COBSQL END-C END |
Signals the end of COBSQL directives; remaining directives, if any, are passed to the precompiler. |
| KEEPCBL | Saves precompiled source file (.cbl). |
| MAKESYN | Converts all COMP host variables to COMP-5 host variables. The default situation, if MAKESYN is not set, is that all variables (not just host variables) are converted from COMP to COMP-5. |
| NOMAKESYN | No conversion of COMP-5 variables or host variables is carried out. |
| SQLDEBUG | Creates a number of files that can be used by Micro Focus to debug COBSQL. These files include the output file from the precompiler (normally this has a .cbl extension), the listing file produced by the precompiler (this has a .lis extension), plus a COBSQL debug file which has a .sdb extension. SQLDEBUG will also turn on KEEPCBL and TRACE. |
| TRACE* | Creates a trace file (.trc). |
| VERBOSE | Displays all precompiler messages and gives status updates as the program is processed. You should only use this when initially verifying that COBSQL is calling the standalone precompiler correctly. |
| BELL* | Controls whether COBSQL sounds the bell when an error occurs. |
| BRIEF* | Controls whether COBSQL shows SQL error text as well as the error number. |
| CONFIRM* | Displays accepted/rejected COBSQL directives. |
| LIST* | Saves the precompiler listing file (.lis). |
| WARNING* | Determines the lowest severity of SQL errors to report. |
The complete set of methods used within COBOL to manipulate copyfiles is not available with database precompilers and COBSQL itself cannot handle included copyfiles. These problems can be overcome, however, by using the Micro Focus Copyfile Preprocessor (CP).
CP is a preprocessor that has been written to provide other preprocessors, such as COBSQL, with a mechanism for handling copyfiles. CP follows the same rules as the COBOL Compiler for handling copyfiles so any copyfile-related Compiler directives are automatically picked up and copyfiles are searched for using the COBCPY environment variable. CP will also expand the following statements:
EXEC SQL INCLUDE ... END-EXEC
Oracle uses .pco and .cob extensions, Sybase uses .pco and .cbl extensions and Informix uses .eco, .cob and .mf2 extensions.
Oracle and Sybase:
For CP to resolve copyfiles and include statements correctly, use the
following COBOL Compiler directives for Sybase and Oracle:
copyext (pco,cbl,cpy,cob) osext(pco)
Informix:
For Informix, use:
copyext (eco,mf2,cbl,cpy,cob) osext(eco)
COBSQL can call CP to expand copyfiles before the database precompiler is invoked. This means that all the copy-related commands are already resolved so that it appears to the database precompiler that a single source file is being used.
The other advantage of using CP is that it makes copyfiles visible when animating.
When CP sees an INCLUDE SQLCA statement, it does the
following:
Note: Using the file sqlca.cpy can result in errors when the program is run.
You can specify the CP preprocessor's SY directive to prevent CP expanding the SQLCA include file, for example:
preprocess"cobsql" preprocess"cp" sy endp
You should always use CP's SY directive when processing Sybase code because Sybase expects to expand the SQLCA itself.
As Oracle can produce code with either COMP or COMP-5 variables, it has two sets of copyfiles. The standard sqlca.cob, oraca.cob and sqlda.cob all have COMP data items. The sqlca5.cob, oraca5.cob and sqlda5.cob files have COMP-5 data items. If you are using the comp5=yes Oracle directive, you must set the COBSQL directive MAKESYN to convert the COMP items in the SQLCA to COMP-5.
If CP produces errors when attempting to locate copyfiles, check to make sure that the OSEXT and COPYEXT Compiler directives are set up correctly. COPYEXT should be set first and should include as its first entry the extension used for source files (.pco or .eco, for example).
If these are set correctly, ensure that the copyfile is either in the current directory or in a directory on the COBCPY path.
When using CP in conjunction with COBSQL, SQL errors inside included copyfiles will be reported correctly. Without CP, the line counts will be wrong, and the error will either go unreported or will appear on the wrong line.
COBSQL error messages can be displayed in different languages depending on the setting of the LANG environment variable. For full details on NLS and how to set the LANG environment variable, see the chapter Internationalization Support in your Programmer's Guide to Writing Programs. For details on the LANG environment variable see the appendix Micro Focus Environment Variables in your Server Express User Guide.
The Cobsql error message cobsql.lng has been translated into a number of different languages and can be found with the COBOL NLS message files. If there is not an error message cobsql.lng for the current setting of LANG, then the default error message file is used.
Note: Cobsql does not translate any error messages produced by the database precompilers.
The following examples show, for the Oracle Sybase and Informix precompilers, command lines that you can enter at the Server Express Command Prompt to compile a program using COBSQL.
Oracle:
cob -a -v -k sample.pco -C "p(cobsql) cstop cobsqltype==ORACLE"
Sybase:
cob -a -v -P -k example1.pco -C"p(cobsql) csp CSQLT==syb"
Informix:
cob -a -k demo1.eco -C "p(cobsql) cobsqltype==informix-new"
If you experience problems using COBSQL, first of all check the following:
Forget SQL, and determine whether the client and server are communicating. For TCP/IP, check whether you can ping the server from the workstation and vice versa. If host names don't work, try raw IP addresses.
Check that the SQL networking software is "talking" correctly to the network software. Many SQL vendors supply a ping utility which will show whether the SQL network is set up correctly.
If the SQL network is okay, try some interactive SQL. Most vendors supply a simple utility that allows you to enter SQL from the keyboard and view the results. Most vendors also supply a sample database that is useful for this purpose.
Verify that the standalone precompiler works. There may be an icon or a command line for the precompiler. Verify that it can produce COBOL code correctly. It is normal for some sample applications to be supplied with the precompiler.
Check that a preprocessed application runs okay. Pass the expanded program through the COBOL Compiler and then try to run it.
Try COBSQL with minimal directives. Set up a project in Server Express, place the SQLCA copyfile into the directory with the sample program (prior to running the precompiler), and see if this works.
Then, if you still experience problems, please contact Micro Focus Support. To help Technical Support locate the cause of the problem:
If you cannot locate the source of the problem, then check each of the following:
Ensure that you are using the latest version of all the products involved.
Check the vendor's documentation and example applications.
Check that environment variables, PATH and configuration file settings are set up correctly.
By default, COBSQL does not display the command line it passes to the database precompiler. Setting the SQLDEBUG directive enables the command line to be displayed (you will need to do this if the precompiler gives command line errors). Possible causes of command line errors are that the directives to be passed to the precompiler are incorrect or that the length of the precompiler command line has been exceeded.
COBSQL may display the following error because the database precompiler has terminated unexpectedly:
* CSQL-F-021: Precompiler did not complete -- Terminating
This may be because the Operating System has run out of memory attempting to execute the database precompiler.
COBSQL may display the following errors because it cannot find the precompiler's output file. This may be because the precompiler did not produce an output file. The normal reason for this is that the precompiler hit a fatal error which meant it could not create the output file.
* CSQL-E-024: Encountered an I/O on file filename * CSQL-E-023: File Status 3 / 5
where filename is the name of the file produced by the database precompiler.
If COBSQL reports the error "Premature end of expanded source", and the precompiler runs correctly, this indicates that COBSQL has not been able to match the original source lines with the lines produced by the database precompiler.
Another possible reason for COBSQL reporting this error is that the program does not contain any SQL. Generally, if the database precompiler does not come across any SQL it will abort the creation of its output file part way through, causing this error to be displayed.
If you are troubleshooting Oracle problems, consider the following:
DBMS HOLD_CURSOR MAXOPENCURSORS MODE RELEASE_CURSOR
The use of arrays enables an application, for example, to fetch ten rows at a time instead of one at a time. Oracle supply an example program (normally called sample3.pco) that uses an array to fetch multiple rows. Arrays are documented in the Pro*Cobol Supplement to the ORACLE Precompilers Guide.
To get the maximum information from Pro*Cobol, set the Pro*Cobol directive xref=yes. This can be added to the Pro*Cobol configuration file, pcccob.cfg.
If you are troubleshooting Sybase problems, consider the following:
If the default setting for the client Operating System has been configured, but Sybase still reports national language support errors, use the LANG environment variable to override the setting in the locales.dat file.
For example if the aix client was causing problems and the locales.dat file contained the following setting for aix:
[aix] locale = C, us_english, iso_1 locale = En_US, us_english, iso_1 locale = en_US, us_english, iso_1 locale = default, us_english, iso_1
then a possible LANG setting for US English would be:
LANG=en_US
SYB-number-type-text
where the parameters are:
| SYB- | A string which indicates to COBSQL that this is a modified Sybase error message. |
| number- | A unique, four digit error number assigned to the Sybase error. |
| type- | Indicates the severity of the error; some of the Sybase messages are only warnings rather than normal or fatal errors. |
| text | The original Sybase error message. |
For example, a typical entry in the esql.loc file might be:
9 = M_PRECLINE, "Warning(s) during check of query on line %1!."
and this would be changed to read:
9 = M_PRECLINE, "SYB-W-2009 Warning(s) during check of query on line %1!."
It is recommended that you make a copy of esql.loc before altering it. Using the modified version, COBSQL can detect the full range of Sybase error messages.
The location of esql.loc is dependent on the language and code page used. This is defined in the locales.dat file. If the definition of the default language for the AIX platform was as follows:
[aix] locale = C, us_english, iso_1 locale = En_US, us_english, iso_1 locale = en_US, us_english, iso_1 locale = default, us_english, iso_1
The default language would be us_english, using the iso_1 code page, so the copy of esql.loc that is to be used is:
/sybase home/locales/messages/us_english/iso_1/esql.loc
where sybase home is the directory that the Sybase client is installed into.
For more information on how Sybase uses and locates the different error message files, refer to your Sybase Client Reference Manual.
If you are troubleshooting Informix problems, consider the following:
copyext(eco,mf2,cob,cpy,cbl) osext(eco)
COBSQL displays four different types of message. These are as follows:
As COBSQL starts, it displays three banner lines which include the COBSQL version number.
The database precompilers produce information about the program that they are compiling. If the COBSQL "Verbose" or "Display" directives are used, then COBSQL will display this information.
All the database precompilers produce error messages. These messages range from those that are displayed for information only to those describing fatal errors. COBSQL attempts to identify the severity of the errors passed to it by the precompiler. It also extracts the precompiler error number and text and attempts to locate the source line on which the error occurred. The format of precompiler error messages is as follows:
precompiler error no.severityprecompiler error text
The precompiler error message is passed to the COBOL Compiler after the source line that the error occurred on, allowing the COBOL Compiler to identify the source line that the error occurred on.
If COBSQL cannot determine the severity of the error passed by the precompiler, it will assume that it is a normal error, rather than a fatal error.
COBSQL itself produces four types of message: information only, warning, error or fatal. Most are fatal. The format of COBSQL errors is as follows:
* CSQL-severity error no. error text
The sections below list current COBSQL messages.
For information only. COBSQL has successfully processed the source file and has passed all the necessary information back to the COBOL Compiler. The program can now be animated or executed. If any errors have been found, these will be highlighted in the source and the error text will be made available.
For information only. It is displayed if the last COBSQLTYPE directive has an incorrect value.COBSQL defaults to using the Oracle precompiler if the COBSQLTYPE directive is not set, is set incorrectly, or is set to an obsolete value.
COBSQL attempts to invoke the Oracle precompiler. This causes further errors if the Oracle precompiler is not present.
Confirms that a COBSQL directive is valid.
COBSQL has encountered directives after the END-COBSQL directive. These directives are for the database precompiler and COBSQL will pass them on. This message is only displayed if the CONFIRM directive is set.
COBSQL has encountered an invalid directive. Either the directive is incorrect or the value supplied for the directive is incorrect.
When COBSQL has to interact with other COBOL Integrated Preprocessors (for example, CP or HTMLPP), it needs to make sure that the subordinate preprocessor(s) are using the same line buffer size as COBSQL. If they are not, this error message is generated. Under normal execution, this message should not appear. If it does, it indicates that an old version of COBSQL is being used with a new Integrated Preprocessor, or vice versa.
Displayed when other Integrated Preprocessors are to be invoked. It is for information only.
The Integrated Preprocessor that COBSQL invoked has returned a fatal error message. COBSQL passes this message to the COBOL Compiler and aborts.
For more information about what might have caused the other Integrated Preprocessor to abort, refer to its documentation.
In a stacked environment (for example when COBSQL invokes another Integrated Preprocessor such as CP), COBSQL stores information returned from the other Integrated Preprocessor in a side file that has an extension of STK. The file has the same basename as the input file.
This message is displayed if COBSQL receives a COBOL error while trying to write out a record to the STK side file. COBSQL also displays error message CSQL-E-023 (file I/O error) giving the COBOL I/O error message.
COBSQL is being run with a version of COBOL for which, to the best of our knowledge, no Informix COBOL precompiler is available. This message is also displayed if the wrong Informix COBSQLTYPE is specified for the COBOL release that COBSQL is running with.
To be able to use the Informix Precompiler, the environment variable INFORMIXDIR must be set. COBSQL uses the value of the INFORMIXDIR environment variable to locate the ESQL/COBOL precompiler.
This error can occur when COBSQL tries to open the source code file, or tries to process a copy statement in the expanded code. COBSQL attempts to open the source file before it invokes the database precompiler. If it cannot open the file, it reports this error.
This error might also be displayed if COBSQL cannot open a copyfile that appears in the expanded source code. COBSQL needs to process copy statements that are inserted by the database precompiler. If COBSQL did not do this, the COBOL Compiler would treat the copy statement as though it appeared in the original source, and expand it.
Once COBSQL has displayed this error, it will also display error message CSQL-E-023 (file I/O error) giving the COBOL I/O error message.
This message is displayed when running under UNIX. On UNIX this is NOT a fatal error. If a database precompiler came across errors in the source file, it is likely it would produce a non-zero return code. Because this might happen, COBSQL will continue after displaying this message.
COBSQL displays this message, for information only, when the expanded source file is to be kept.
COBSQL displays this message, for information only, to let the user know which database precompiler is about to be called.
COBSQL has attempted to open the STK side file. This file is only used when COBSQL is stacked with other Integrated Precompilers.
COBSQL also displays error message CSQL-E-023 (file I/O error) giving the COBOL I/O error message.
COBSQL displays this message once it has successfully called the database precompiler and is about to start processing the expanded code.
After calling the database precompiler COBSQL checks to make sure that it completed. It does this by trying to open the files that the precompiler should have produced. If it cannot open the files, it reports this error.
If this message is displayed and the precompiler has created both a listing file and the expanded source code, then either COBSQL does not have read permissions on the files, or they have been created in the wrong directory. Ensure that the current directory is set correctly before running COBSQL.
As part of the processing performed after the database precompiler has completed, COBSQL reopens the original source code file. If COBSQL cannot open the file, it displays this error message.
COBSQL also displays error message CSQL-E-023 (file I/O error) giving the COBOL I/O error message.
COBSQL displays this error message after a file operation has failed. This message is normally preceded by another COBSQL error message identifying the file in error.
Displayed when a write error occurs on either the trace or the debug file.
COBSQL also displays error message CSQL-E-023 (file I/O error) giving the COBOL I/O error message.
To process the source file and the expanded code, COBSQL needs to create a number of virtual heaps. If there is a problem when COBSQL tries to create a heap, this message is displayed indicating which heap COBSQL had problems creating.
The most likely cause of this problem is that not enough memory is available or that too many virtual heaps have already been created. The solution is to close down some COBOL applications to free up memory or virtual file slots.
COBSQL has reached the end of the expanded source code before it reached the end of the original source code. There are two possible reasons for this.
The item area-of-code corresponds to the position within the original source code that COBSQL was processing. These areas include Working-Storage, Procedure Division and SQL statements.
The item lines of source code identifies the original source code lines that COBSQL was processing. These are displayed as they can indicate where the problem lies in the original source code.
Displayed, for information only, when COBSQL is running in VERBOSE mode. It indicates that COBSQL has encountered the Working Storage Section and is about to process it.
Displayed, for information only, when COBSQL is running in VERBOSE mode. It indicates that COBSQL has encountered the Procedure Division and is about to process it.
Displayed, for information only, when COBSQL is running in VERBOSE mode. It indicates that COBSQL has encountered an EXEC SQL statement within the procedure division of a program and is about to process it.
As part of the processing performed after the database precompiler has completed, COBSQL opens the expanded source code file. If COBSQL cannot open the file, it displays this message.
COBSQL also displays error message CSQL-E-023 (file I/O error) giving the COBOL I/O error message.
COBSQL is being run with an old version of COBOL and will not work correctly. Because of this, COBSQL terminates rather than trying to continue.
COBSQL has encountered a directive that is now marked as obsolete.
COBSQL sometimes tries to re-position itself when working through the original source file (ORG) and the source produced by the database precompiler (CBL). It does this by scanning ahead in the CBL file to try to find a matching line. If it does, it displays this message.
The usual reason for a mismatch between the two source files is that the precompiler has produced code that COBSQL is not able to cope with. Until COBSQL is altered to cope with this, using the SQLDEBUG directive provides a temporary work-around.
The code produced when this message has been displayed may not function correctly because some of the original source may have been removed so that COBSQL can re-position itself.
Pro*COBOL has commented out a line of code that was not a part of an EXEC SQL statement. This may alter the way that the program executes and care should be taken if the application is run.
COBSQL tries to determine how the current run-time is configured by examining the settings of the run-time switches. This error is displayed if COBSQL cannot read the current settings.
This error causes COBSQL to abort.
Some external code generators produce COBOL code which contains null characters. COBSQL reads the settings of the run-time switches and attempts to change the settings of the relevant switches in order to enable it to read code containing null characters.
This message is displayed if COBSQL has successfully read the run-time switches but has failed in its attempt to set them.
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| SQL, DB2/2 and 32-bit COBOL | Interface to Informix DBMS | |