Application Building Guide

SPARCompiler C

This section explains how to use SPARCompiler C with the following kinds of DB2 interfaces:

• DB2 APIs
• DB2 CLI
• Embedded SQL

DB2 API Applications

The script file, bldccapi, in sqllib/samples/c, contains the commands to build a DB2 API program. The parameter, $1, specifies the name of your source file.

#! /bin/ksh # bldccapi script file # Builds a C DB2 API program. # Usage: bldccapi <prog_name> # Set DB2PATH to where DB2 will be accessed. # The default is the standard instance path. DB2PATH=$HOME/sqllib # Compile the util.c error-checking utility. cc -I$DB2PATH/include -c util.c # Compile the program. cc -I$DB2PATH/include -c $1.c # Link the program. cc -o $1 $1.o util.o -L$DB2PATH/lib -R$DB2PATH/lib -ldb2

Compile and Link Options for bldccapi
The script file contains the following compile options: cc The C compiler. -I$DB2PATH/include Specify the location of the DB2 include files. For example: $HOME/sqllib/include -c Perform compile only; no link. This book assumes that compile and link are separate steps.
The script file contains the following link options: cc Use the compiler as a front end for the linker. -o $1 Specify the executable. $1.o Include the program object file. util.o Include the utility object file for error checking. -L$DB2PATH/lib Specify the location of the DB2 static and shared libraries at link-time. For example: $HOME/sqllib/lib. If you do not specify the -L option, /usr/lib:/lib is assumed. -R$DB2PATH/lib Specify the location of the DB2 shared libraries at run-time. For example: $HOME/sqllib/lib. -ldb2 Link with the DB2 library. Refer to your compiler documentation for additional compiler options.

To build the sample program client from the source file client.c , enter:

   bldccapi client

The result is an executable file, client. You can run the executable file against the sample database by entering the executable name:

   client

DB2 CLI Applications

The script file bldcli in sqllib/samples/cli contains the commands to build a DB2 CLI program. The parameter, $1, specifies the name of your source file.

#! /bin/ksh # bldcli script file -- Solaris # Builds a DB2 CLI program. # Usage: bldcli <prog_name> # Set DB2PATH to where DB2 will be accessed. # The default is the standard instance path. DB2PATH=$HOME/sqllib # Compile the error-checking utility. cc -I$DB2PATH/include -c samputil.c # Compile the program. cc -I$DB2PATH/include -c $1.c # Link the program. cc -o $1 $1.o samputil.o -L$DB2PATH/lib -R$DB2PATH/lib -ldb2

Compile and Link Options for bldcli
The script file contains the following compile options: cc Use the C compiler. -I$DB2PATH/include Specify the location of the DB2 include files. For example: $HOME/sqllib/include -c Perform compile only; no link. This book assumes that compile and link are separate steps.
The script file contains the following link options: cc Use the compiler as a front end for the linker. -o $1 Specify the executable program. $1.o Include the program object file. samputil.o Include the utility object file for error checking. -L$DB2PATH/lib Specify the location of the DB2 static and shared libraries at link-time. For example, $HOME/sqllib/lib -R$DB2PATH/lib Specify the location of the DB2 shared libraries at run-time. For example, $HOME/sqllib/lib -ldb2 Link with the DB2 library. Refer to your compiler documentation for additional compiler options.

To build the sample program basiccon from the source file basiccon.c , enter:

 
   bldcli basiccon

The result is an executable file basiccon. You can run the executable file by entering the executable name:

   basiccon

DB2 CLI Stored Procedures

The script file bldclisp in sqllib/samples/cli contains the commands to build a DB2 CLI stored procedure. The parameter, $1, specifies the name of your source file.

#! /bin/ksh # bldclisp script file -- Solaris # Builds a DB2 CLI stored procedure. # Usage: bldclisp <prog_name> # Set DB2PATH to where DB2 will be accessed. # The default is the standard instance path. DB2PATH=$HOME/sqllib # Compile the error-checking utility. cc -Kpic -I$DB2PATH/include -c samputil.c # Compile the program. cc -Kpic -I$DB2PATH/include -c $1.c # Link the program. cc -o $1 $1.o samputil.o -L$DB2PATH/lib -R$DB2PATH/lib -ldb2 -G # Copy the shared library to the sqllib/function subdirectory of the DB2 instance. # This assumes the user has write permission to this directory. rm -f $DB2PATH/function/$1 cp $1 $DB2PATH/function

Compile and Link Options for bldclisp
The script file contains the following compile options: cc The C compiler. -Kpic Generate position-independent code for shared libraries. -I$DB2PATH/include Specify the location of the DB2 include files. For example: $HOME/sqllib/include. -c Perform compile only; no link. This book assumes that compile and link are separate steps.
The script file contains the following link options: cc Use the compiler as a front end for the linker. -o $1 Specify the executable. $1.o Include the program object file. samputil.o Include the utility object file for error-checking. -L$DB2PATH/lib Specify the location of the DB2 static and shared libraries at link-time. For example: $HOME/sqllib/lib. If you do not specify the -L option, /usr/lib:/lib is assumed. -R$DB2PATH/lib Specify the location of the DB2 shared libraries at run-time. For example: $HOME/sqllib/lib. -ldb2 Link with the DB2 library. -G Generate a shared library. Refer to your compiler documentation for additional compiler options.

To build the sample program outsrv2 from source file outsrv2.c , enter:

   bldclisp outsrv2

The script file copies the stored procedure to the server in the path sqllib/function. For DB2DARI parameter style stored procedures where the invoked procedure matches the shared library name, this location indicates that the stored procedure is fenced. If you want this type of stored procedure to be unfenced, you must move it to the sqllib/function/unfenced directory. For all other types of DB2 stored procedures, you indicate whether it is fenced or not fenced with the CREATE FUNCTION statement in the calling program. For a full discussion on creating and using the different types of DB2 stored procedures, please see the "Stored Procedures" chapter in the Application Development Guide.

Note:

An unfenced stored procedure runs in the same address space as the database manager and results in increased performance when compared to a fenced stored procedure, which runs in an address space isolated from the database manager. With unfenced stored procedures there is a danger that user code could accidentally or maliciously damage the database control structures. Therefore, you should only run unfenced stored procedures when you need to maximize the performance benefits. Ensure these programs are thoroughly tested before running them as unfenced. Refer to the Application Development Guide for more information.

If necessary, set the file mode for the stored procedure so the DB2 instance can run it.

Once you build the stored procedure outsrv2, you can build the CLI client application outcli2.c that calls the stored procedure. You can build outcli2 by using the script file bldcli. Refer to "DB2 CLI Applications" for details.

To call the stored procedure, run the sample client application by entering:

   outcli2 remote_database userid password

where

remote_database

Is the name of the database to which you want to connect. The name could be sample, or its remote alias, or some other name.

userid

Is a valid user ID.

password

Is a valid password.

The client application passes a variable to the server program outsrv2, which gives it a value and then returns the variable to the client application.

Embedded SQL Applications

The script file, bldcc, in sqllib/samples/c, contains the commands to build an embedded SQL 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> ]]
 
# Set DB2PATH to where DB2 will be accessed. 
# The default is the standard instance path.
DB2PATH=$HOME/sqllib
 
# 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$DB2PATH/include -c util.c
 
# Compile the program.
cc -I$DB2PATH/include -c $1.c
 
# Link the program.
cc -o $1 $1.o util.o -L$DB2PATH/lib -R$DB2PATH/lib -ldb2

Compile and Link Options for bldcc
The script file contains the following compile options: cc The C compiler. -I$DB2PATH/include Specify the location of the DB2 include files. For example: $HOME/sqllib/include -c Perform compile only; no link. This book assumes that compile and link are separate steps.
The script file contains the following link options: cc Use the compiler as a front end for the linker. -o $1 Specify the executable. $1.o Include the program object file. util.o Include the utility object file for error-checking. -L$DB2PATH/lib Specify the location of the DB2 static and shared libraries at link-time. For example: $HOME/sqllib/lib. If you do not specify the -L option, /usr/lib:/lib is assumed. -R$DB2PATH/lib Specify the location of the DB2 shared libraries at run-time. For example: $HOME/sqllib/lib. -ldb2 Link with the DB2 library. Refer to your compiler documentation for additional compiler options.

To build the sample program updat from the source file updat.sqc , enter:

   bldcc updat

The result is an executable file updat. You can run the executable file against the sample database by entering the executable name:

   updat

Embedded SQL Stored Procedures

The script file, bldccsrv, in sqllib/samples/c, contains the commands to build an embedded SQL 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> ]]
 
# Set DB2PATH to where DB2 will be accessed. 
# The default is the standard instance path.
DB2PATH=$HOME/sqllib
 
# 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 -Kpic -I$DB2PATH/include -c util.c
 
# Compile the program.
cc -Kpic -I$DB2PATH/include -c $1.c
 
# Link the program and create a shared library
cc -G -o $1 $1.o -L$DB2PATH/lib -R$DB2PATH/lib -ldb2
 
# Copy the shared library to the sqllib/function subdirectory of the DB2 instance.
# This assumes the user has write permission to this directory.
rm -f $DB2PATH/function/$1
cp $1 $DB2PATH/function

Compile and Link Options for bldccsrv
The script file contains the following compile options: cc The C compiler. -Kpic Generate position-independent code for shared libraries. -I$DB2PATH/include Specify the location of the DB2 include files. For example: -I$DB2PATH/include -c Perform compile only; no link. This book assumes that compile and link are separate steps.
The script file contains the following link options: cc Use the compiler as a front end for the linker. -G Generate a shared library. -o $1 Specify the executable. $1.o Include the program object file. -L$DB2PATH/lib Specify the location of the DB2 static and shared libraries at link-time. For example: $HOME/sqllib/lib. If you do not specify the -L option, /usr/lib:/lib is assumed. -R$DB2PATH/lib Specify the location of the DB2 shared libraries at run-time. For example: $HOME/sqllib/lib. -ldb2 Link with the DB2 library. Refer to your compiler documentation for additional compiler options.

To build the sample program outsrv from the source file outsrv.sqc , enter:

   bldccsrv outsrv

The script file copies the stored procedure to the server in the path sqllib/function. For DB2DARI parameter style stored procedures where the invoked procedure matches the shared library name, this location indicates that the stored procedure is fenced. If you want this type of stored procedure to be unfenced, you must move it to the sqllib/function/unfenced directory. For all other types of DB2 stored procedures, you indicate whether it is fenced or not fenced with the CREATE FUNCTION statement in the calling program. For a full discussion on creating and using the different types of DB2 stored procedures, please see the "Stored Procedures" chapter in the Application Development Guide.

Note:

An unfenced stored procedure runs in the same address space as the database manager and results in increased performance when compared to a fenced stored procedure, which runs in an address space isolated from the database manager. With unfenced stored procedures there is a danger that user code could accidentally or maliciously damage the database control structures. Therefore, you should only run unfenced stored procedures when you need to maximize the performance benefits. Ensure these programs are thoroughly tested before running them as unfenced. Refer to the Application Development Guide for more information.

If necessary, set the file mode for the stored procedure so the DB2 instance can run it.

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 script file bldcc. Refer to "Embedded SQL Applications" for details.

To call the stored procedure, run the sample client application by entering:

  outcli remote_database userid password

where

remote_database

Is the name of the database to which you want to connect. The name could be sample, or its remote alias, or some other name.

userid

Is a valid user ID.

password

Is a valid password.

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.

User-Defined Functions (UDFs)

The script file, bldccudf, in sqllib/samples/c, contains the commands to build a UDF. UDFs do not contain embedded SQL statements. Therefore, to build a UDF program, you do not connect to a database or precompile and bind the program.

The parameter, $1, specifies the name of your source file. The script file uses the source file name for the shared library name.

#! /bin/ksh # bldccudf script file # Builds a C user-defined function library. # Usage: bldccudf <prog_name> # Set DB2PATH to where DB2 will be accessed. # The default is the standard instance path. DB2PATH=$HOME/sqllib # Compile the program. cc -Kpic -I$DB2PATH/include -c $1.c # Link the program and create a shared library. cc -o $1 $1.o -L$DB2PATH/lib -R$DB2PATH/lib -ldb2 -ldb2apie -G # Copy the shared library to the sqllib/function subdirectory of the DB2 instance. # This assumes the user has write permission to this directory. rm -f $DB2PATH/function/$1 cp $1 $DB2PATH/function

Compile and Link Options for bldccudf
The script file contains the following compile options: cc The C compiler. -Kpic Generate position-independent code for shared libraries. -I$DB2PATH/include Specify the location of the DB2 include files. For example: $HOME/sqllib/include. -c Perform compile only; no link. This book assumes that compile and link are separate steps.
The script file contains the following link options: cc Use the compiler as a front end for the linker. -o $1 Specify the executable. $1.o Include the program object file. -L$DB2PATH/lib Specify the location of the DB2 static and shared libraries at link-time. For example: $HOME/sqllib/lib. If you do not specify the -L option, /usr/lib:/lib is assumed. -R$DB2PATH/lib Specify the location of the DB2 shared libraries at run-time. For example: $HOME/sqllib/lib. -ldb2 Link with the DB2 library. -ldb2apie Link with the DB2 API Engine library to allow the use of LOB locators. -G Generate a shared library. Refer to your compiler documentation for additional compiler options.

To build the user-defined function program udf from the source file udf.c , enter:

   bldccudf udf

The script file copies the UDF to the server in the path sqllib/function.

If necessary, set the file mode for the UDF so the DB2 instance can run it.

Once you build udf, you can build the client application, calludf, that calls it. DB2 CLI and embedded SQL versions of this program are provided. You can build the DB2 CLI calludf program from the calludf.c source file in sqllib/samples/cli using the script file bldcli. Refer to "DB2 CLI Applications" for details.

You can build the embedded SQL calludf program from the calludf.sqc source file in sqllib/samples/c using the script file bldcc. Refer to "Embedded SQL Applications" for details.

To call the UDF, run the sample calling application by entering:

calludf

The calling application calls functions from the udf library.

Multi-threaded Applications

Multi-threaded applications using SPARCompiler C on Solaris need to be compiled and linked with -mt. This will pass -D_REENTRANT to the preprocessor, and -lthread to the linker. Posix threads also require -lpthread to be passed to the linker. In addition, using the compiler option -D_POSIX_PTHREAD_SEMANTICS allows posix variants of functions such as getpwnam_r().

The script file, bldccmt, in sqllib/samples/c, contains the commands to build an embedded SQL multi-threaded program. If you want to build a DB2 API or DB2 CLI multi-threaded program, comment out the connect, precompile, bind, and disconnect commands. For DB2 CLI, also substitute the samputil.c and samputil.o files for util.c and util.o.

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 
# bldccmt script file -- Solaris
# Builds an embedded SQL multi-threaded program.
# Usage: bldccmt <prog_name> [ <db_name> [ <userid> <password> ]]
 
# Set DB2PATH to where DB2 will be accessed. 
# The default is the standard instance path.
DB2PATH=$HOME/sqllib
 
# 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 -mt -D_POSIX_PTHREAD_SEMANTICS -I$DB2PATH/include -c util.c
# Compile the program.                                 
cc -mt -D_POSIX_PTHREAD_SEMANTICS -I$DB2PATH/include -c $1.c               
# Link the program                                      
cc -mt -o $1 $1.o util.o -L$DB2PATH/lib -R$DB2PATH/lib -ldb2 -lpthread

Besides the -mt, -D_POSIX_PTHREAD_SEMANTICS, and -lpthread options, discussed above, the other compile and link options are the same as those used for the embedded SQL script file, bldcc. For information on these options, see "Embedded SQL Applications".

To build the sample program, thdsrver, from the source file thdsrver.sqc , enter:

   bldccmt thdsrver

The result is an executable file, thdsrver. To run the executable file against the sample database, enter:

   thdsrver

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