Application program in C

CogitoErgoSum · #1 (**permalink**) 12-24-09, 08:24

I have installed DB2 Runtime Client and yet do not see the SQL related include files. What am I missing ?

I have gone through the DB2 Developer Handbook (IBM Redbook), 'Getting Started with Database application programming' but I am unable to find out how to obtain (if that is the right word) the include files.

Help !

n_i · #2 (**permalink**) 12-24-09, 09:09

May be you need an Application Development Client instead?

CogitoErgoSum · #3 (**permalink**) 12-24-09, 09:18

Hi Nick,
What is an Application Development Client ?

The Getting Started Guide mentioned the Runtime Client though.

stolze · #4 (**permalink**) 12-28-09, 01:58

The Runtime Client allows an existing application to connect to a DB2 server. No header files are needed for that - only the libraries. If you want to develop new applications, you'll need the header files, which are part of the Application Development Client.

CogitoErgoSum · #5 (**permalink**) 12-28-09, 02:56

Hi Stolze,
I kind of solved that problem when I reinstalled DB2 Express-C. I was also able to compile and link successfully.

stolze · #6 (**permalink**) 12-28-09, 06:52

Yes, Express-C includes the Development client.

CogitoErgoSum · #7 (**permalink**) 12-29-09, 00:16

However, I am now getting weird message when running the code :

Code:

./runtest: symbol lookup error: /opt/ibm/db2/V9.7/lib32/libdb2.so.1: undefined symbol: sqlnlsgmsg

I gave up on C and tried in Java (JDBC Type 4 connectivity). I tried with correct JDBC URL and the connection does not happen at all. I will try to recreate and respond with proper error messages. The database is installed on my Ubuntu laptop.

This is exasperating ! :-(

However, with the same Java app, when I provide JDBC URL to the DB2 database of our customer's application (on AIX 64-bit), the connection happens straightaway !

stolze · #8 (**permalink**) 12-29-09, 02:31

I am using DB2 V9.5 on my laptop with Linux, so it may not fit exactly your situation. But I found that sqlnlsgmsg is nowhere used in any header file. There is a symbol "sqlnlsgmsg_cpcv" used in libdb2 and defined in libdb2g11n. Maybe you didn't link with the other or don't have the linker path set up correctly?

CogitoErgoSum · #9 (**permalink**) 12-29-09, 02:46

This is my link statement

Code:

gcc -o runtest runtest.o -Wl,-rpath,/opt/ibm/db2/V9.7/lib32 -L/opt/ibm/db2/V9.7/lib32 -ldb2

I "copied" it from the bldapp file in the samples folder

Code:

/opt/ibm/db2/V9.7/samples/c

CogitoErgoSum · #10 (**permalink**) 12-29-09, 02:47

I copied the link step from the bldapp file in the C directory in the samples folder.

Code:

gcc -o runtest runtest.o -Wl,-rpath,/opt/ibm/db2/V9.7/lib32 -L/opt/ibm/db2/V9.7/lib32 -ldb2

stolze · #11 (**permalink**) 12-29-09, 04:12

It really depends on your platform and what you want to do. Some applications need, for example, to link with libdb2api, which is not part of the "bldapp" script.

Another aspect is that I wouldn't use the hard-coded path to /opt/ibm/db2/... but rather $HOME/sqllib/lib. That way, you will automatically get the correct version of the libraries in case you have multiple DB2 version installed, and 32bit vs. 64bit is also resolved for you already.

CogitoErgoSum · #12 (**permalink**) 12-29-09, 07:27

Hi Knut,
Thanks for looking into this !

I have uninstalled DB2 Express-C and then did a fresh install with a new instance. I am now able to connect through JDBC successfully.

I will check the C application's connectivity later tonight and report back.

CogitoErgoSum · #13 (**permalink**) 12-30-09, 01:05

I am now able to connect from C and JDBC successfully.

However, with a new C program (that has cursors in it), fails pre-compiling because of undeclared host variables. I will start a new thread for this.

Thank you, all !

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