The compile and link steps in the script files in this section are for Sparcompiler C. They also contain, commented out, the compile and link steps for the IBM C Set++ compiler. To use the scripts with this compiler, just comment out the Sparcompiler compile and link steps and uncomment those for C Set++.
The script files are coded for C programs using a C compiler. To use C++ programs you need to use a C++ compiler. To do this, make the changes to the script files given in comments at the end of the files.
The script file bldcc, in sqllib/samples/c, contains the commands to build a sample C program.
The first parameter, $1, specifies the name of your source file. The second parameter, $2, specifies the name of the database to which you want to connect. The third parameter, $3, specifies the user ID for the database, and $4 specifies the password. Only the first parameter, the source file name, is required. Database name, user ID, and password are optional. If no database name is supplied, the program uses the default sample database.
#! /bin/ksh # bldcc script file # Builds a sample c program. # Usage: bldcc <prog_name> [ <db_name> [ <userid> <password> ]] # Connect to a database. if (($# < 2)) then db2 connect to sample elif (($# < 3)) then db2 connect to $2 else db2 connect to $2 user $3 using $4 fi # Precompile the program. db2 prep $1.sqc bindfile # Bind the program to the database. db2 bind $1.bnd # Disconnect from the database. db2 connect reset # Compile the util.c error-checking utility. cc -I/opt/IBMdb2/v5.0/include -c util.c # Compile the program. (Using the SPARCompiler C compiler) cc -I/opt/IBMdb2/v5.0/include -c $1.c # Link the program. cc -o $1 $1.o util.o -L/opt/IBMdb2/v5.0/lib -R/opt/IBMdb2/v5.0/lib -ldb2 # Using the IBM C Set++ compiler. # Compile the util.c error-checking utility. # xlc -I/opt/IBMdb2/v5.0/include -c util.c # Compile the program. # xlc -I/opt/IBMdb2/v5.0/include -c $1.c # Link the program. # xlc -o $1 $1.o util.o -L/opt/IBMdb2/v5.0/lib -R/opt/IBMdb2/v5.0/lib -ldb2 # To compile C++ Programs. # Change 'cc' to 'CC' in the compile and link steps or 'xlc' to 'xlC' for IBM C Set++. # Change '.sqc' to '.sqC' in the precompile step and '.c' to '.C' in the compile step. |
| Compile and Link Options for bldcc |
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The script file contains the following compile options:
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The script file contains the following link options:
Refer to your compiler documentation for additional compiler options.
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To build the sample program updat.sqc, do the following:
db2start
bldcc updat
The result is an executable file updat. You can run the executable file against the SAMPLE database to see how it works by doing the following :
db2start
updat
| Note: | To build C applications that do not contain embedded SQL, you can use the script file bldccapi. It contains the same compile and link options as bldcc, but does not connect, prep, bind, or disconnect from the SAMPLE database. It is used to compile and link the DB2 API sample programs written in C. |
The script file bldccsrv, in sqllib/samples/c, contains the commands to build a C stored procedure. The script file compiles the stored procedure into a shared library that can be called by a client application.
The first parameter, $1, specifies the name of your source file. The second parameter, $2, specifies the name of the database to which you want to connect. The third parameter, $3, specifies the user ID for the database, and $4 specifies the password. Only the first parameter, the source file name, is required. Database name, user ID, and password are optional. If no database name is supplied, the program uses the default sample database.
The script file uses the source file name, $1, for the shared library name.
#! /bin/ksh # bldccsrv script file # Build sample c stored procedure. # Usage: bldccsrv <prog_name> [ <db_name> [ <userid> <password> ]] # Connect to a database. if (($# < 2)) then db2 connect to sample elif (($# < 3)) then db2 connect to $2 else db2 connect to $2 user $3 using $4 fi # Precompile the program. db2 prep $1.sqc bindfile # Bind the program to the database. db2 bind $1.bnd # Disconnect from the database. db2 connect reset # Compile the util.c error-checking utility. cc -Xa -misalign -Kpic -I/opt/IBMdb2/v5.0/include -c util.c # Compile the program. (Using the SPARCompiler C compiler) cc -Xa -misalign -Kpic -I/opt/IBMdb2/v5.0/include -c $1.c # Link the program and create a shared library cc -G -o $1 $1.o -L/opt/IBMdb2/v5.0/lib -R/opt/IBMdb2/v5.0/lib -ldb2 -e$1 # Using the IBM C Set++ compiler. # Compile the util.c error-checking utility. # xlc -qmisalign -qpic=small -I/opt/IBMdb2/v5.0/include -c util.c # Compile the program. # xlc -qmisalign -qpic=small -I/opt/IBMdb2/v5.0/include -c $1.c # Link the program and create a shared library # xlc -G -o $1 $1.o -L/opt/IBMdb2/v5.0/lib -R/opt/IBMdb2/v5.0/lib -ldb2 -e$1 # Copy the shared library to the sqllib/function subdirectory of the DB2 instance. # Note: this assumes the user has write permission to this directory. eval "H=~$DB2INSTANCE" cp $1 $H/sqllib/function # To compile C++ Programs, change 'cc' to 'CC' in the compile and link steps or # 'xlc' to 'xlC' for IBM C Set++. Change '.sqc' to '.sqC' in the precompile step. # In the compile step change '.c' to '.C' and do not use '-Xa'. In the link step # do not use '-e$1'. Ensure the stored procedure is coded with extern "C". |
| Compile and Link Options for bldccsrv |
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The script file contains the following compile options:
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The script file contains the following link options:
Refer to your compiler documentation for additional compiler options.
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To build the outsrv.sqc stored procedure, do the following:
db2start
bldccsrv outsrv
The script file copies the stored procedure to the server in the path sqllib/function to indicate that the stored procedure is fenced. If you want the stored procedure to be unfenced, you must move it to the sqllib/function/unfenced directory. These paths are in the home directory of the DB2 instance.
| Note: | An unfenced stored procedure or UDF runs in the same address space as the database manager and results in increased performance when compared to a fenced stored procedure or UDF, which runs in an address space isolated from the database manager. With unfenced stored procedures or UDFs there is a danger that user code could accidentally or maliciously damage the database control structures. Therefore, you should only run unfenced stored procedures or UDFs when you need to maximize the performance benefits. Ensure these programs are thoroughly tested before running them as unfenced. Refer to the Embedded SQL Programming Guide for more information about fenced and not fenced stored procedures. |
Once you build the stored procedure outsrv, you can build the client application outcli that calls the stored procedure. You can build outcli using the bldcc file. Refer to "SPARCompiler C/C++" for details.
To run the stored procedure, do the following :
db2start
outcli remote_database userid password
where
The client application passes a variable to the server program outsrv, which gives it a value and then returns the variable to the client application.
The script file bldccudf, in sqllib/samples/c, contains the commands to build a UDF. UDFs are compiled like stored procedures, but you do not need to connect to a database or precompile and bind the program.
| Note: | A UDF does not contain embedded SQL statements. Rather, the application that uses the UDF contains the statements, such as calludf. |
The first parameter, $1, specifies the name of your source file. The script file also uses this source file name for the shared library name.
#! /bin/ksh # bldccudf script file # Builds a C user-defined function library. # Usage: bldccudf <prog_name> # Compile the program. (Using the SPARCompiler C compiler) cc -Xa -misalign -Kpic -I/opt/IBMdb2/v5.0/include -c $1.c # Link the program and create a shared library. cc -o $1 $1.o -L/opt/IBMdb2/v5.0/lib -R/opt/IBMdb2/v5.0/lib -ldb2 -ldb2apie -G # Using the IBM C Set++ compiler. # Compile the program. # xlc -qmisalign -qpic=small -I/opt/IBMdb2/v5.0/include -c $1.c # Link the program and create a shared library. # xlc -o $1 $1.o -L/opt/IBMdb2/v5.0/lib -R/opt/IBMdb2/v5.0/lib -ldb2 -ldb2apie -G # Copy the shared library to the sqllib/function subdirectory of the DB2 instance. # Note: this assumes the user has write permission to this directory. eval "H=~$DB2INSTANCE" cp $1 $H/sqllib/function # To compile C++ Programs, change 'cc' to 'CC' in the compile and link steps # or 'xlc' to 'xlC' for IBM C Set++. In the precompile step change '.sqc' to '.sqC'. # In the compile step change '.c' to '.C' and do not use '-Xa'. # Ensure the UDF is coded with extern "C". |
| Compile and Link Options for bldccudf |
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The script file contains the following compile options:
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The script file contains the following link options:
Refer to your compiler documentation for additional compiler options.
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To build the user-defined function udf, do the following:
bldccudf udf
The script file copies the UDF to the server in the path sqllib/function to indicate that the UDF is fenced. If you want the UDF to be unfenced, you must move it to the sqllib/function/unfenced directory. These paths are in the home directory of the DB2 instance.
| Note: | An unfenced UDF or stored procedure runs in the same address space as the database manager and results in increased performance when compared to a fenced UDF or stored procedure, which runs in an address space isolated from the database manager. With unfenced UDFs or stored procedures there is a danger that user code could accidentally or maliciously damage the database control structures. Therefore, you should only run unfenced UDFs or stored procedures when you need to maximize the performance benefits. Ensure these programs are thoroughly tested before running them as unfenced. Refer to the Embedded SQL Programming Guide for more information about fenced and not fenced UDFs. |
Once you build udf, you can build the client application, calludf, that calls it. You can build calludf using the bldcc file. Refer to "SPARCompiler C/C++" for details.
To run the UDF, do the following :
db2start
calludf
The calling application calls functions from the udf library.
Multi-threaded applications on Solaris need to be compiled with the -D_REENTRANT flag, and linked with libthread.so. Add -D_REENTRANT following the cc or xlc compile command, and add -lthread to the end of the link command, when building a multi-threaded application.