go_ibm_db

Interface for GoLang to DB2 for z/OS, DB2 for LUW and DB2 for i database servers.

API Documentation

For complete list of go_ibm_db APIs and examples please check APIDocumentation.md

Prerequisite

• Golang should be installed(Golang version should be >=1.12.x and <= 1.21.X)

• Git should be installed in your system.

• For non-windows users, GCC and tar should be present in your system.

• For Docker Linux Container(Ex: Amazon Linux2), use below commands:

yum install go git tar libpam

Note:

• Environment variable DB2HOME is changed to IBM_DB_HOME.

• SQL1598N Error - It is expected in absence of valid db2connect license. Please click here and read instructions about license requirement and how to apply the license.

How to Install in Windows

• You may install go_ibm_db using either of below commands

go get -d github.com/ibmdb/go_ibm_db
go install github.com/ibmdb/go_ibm_db/installer@latest
go install github.com/ibmdb/go_ibm_db/installer@v0.4.5

• You can optionally specify a specific cli driver by setting the IBM_DB_DOWNLOAD_URL environment variable to the full path of your desired cli driver. For example, if you want to install the 64-bit macos v11.5.4 cli driver instead of the latest one, set the variable as below:

export IBM_DB_DOWNLOAD_URL=https://public.dhe.ibm.com/ibmdl/export/pub/software/data/db2/drivers/odbc_cli/v11.5.4/macos64_odbc_cli.tar.gz

• If you already have a clidriver available in your system, add the path of the same to your PATH windows environment variable. Example: set PATH = "C:\Program Files\IBM\IBM DATA SERVER DRIVER\bin";%PATH%

• If you do not have a clidriver in your system, go to installer folder where go_ibm_db is downloaded in your system, use below command: (Example: C:\Users\uname\go\src\github.com\ibmdb\go_ibm_db\installer or C:\Users\uname\go\pkg\mod\github.com\ibmdb\go_ibm_db\installer where uname is the username ) and run setup.go file (go run setup.go).

Set IBM_DB_HOME to clidriver downloaded path and
set this path to your PATH windows environment variable
(Example: Path=C:\Users\uname\go\src\github.com\ibmdb\clidriver)
set IBM_DB_HOME=C:\Users\uname\go\src\github.com\ibmdb\clidriver
set PATH=%PATH%;C:\Users\uname\go\src\github.com\ibmdb\clidriver\bin
or 
set PATH=%PATH%;%IBM_DB_HOME%\bin

• Script file to set environment variable

cd .../go_ibm_db/installer
setenvwin.bat

How to Install in Linux/Mac

• You may install go_ibm_db using either of below commands

go get -d github.com/ibmdb/go_ibm_db
go install github.com/ibmdb/go_ibm_db/installer@latest
go install github.com/ibmdb/go_ibm_db/installer@v0.4.5

• You can optionally specify a specific cli driver by setting the IBM_DB_DOWNLOAD_URL environment variable to the full path of your desired driver. For example, if you want to install the 64-bit macos v11.5.4 cli driver instead of the latest one, set the variable as below:

export IBM_DB_DOWNLOAD_URL=https://public.dhe.ibm.com/ibmdl/export/pub/software/data/db2/drivers/odbc_cli/v11.5.4/macos64_odbc_cli.tar.gz

• If you already have a clidriver available in your system, set the below environment variables with the clidriver path

export IBM_DB_HOME=/home/uname/clidriver
export CGO_CFLAGS=-I$IBM_DB_HOME/include
export CGO_LDFLAGS=-L$IBM_DB_HOME/lib 
Linux:
export LD_LIBRARY_PATH=/home/uname/clidriver/lib
or
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$IBM_DB_HOME/lib
Mac:
export DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH:/Applications/clidriver/lib

• If you do not have a clidriver available in your system, use below commands. (Example: /home/uname/go/src/github.com/ibmdb/go_ibm_db/installer or /home/uname/go/pkg/mod/github.com/ibmdb/go_ibm_db/installer where uname is the username) and run setup.go file (go run setup.go)

export IBM_DB_HOME=/home/uname/go/src/github.com/ibmdb/clidriver
export CGO_CFLAGS=-I$IBM_DB_HOME/include
export CGO_LDFLAGS=-L$IBM_DB_HOME/lib
Linux:
export LD_LIBRARY_PATH=/home/uname/go/src/github.com/ibmdb/clidriver/lib
or
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$IBM_DB_HOME/lib
Mac:
export DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH:/home/uname/go/src/github.com/ibmdb/clidriver/lib
or
export DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH:$IBM_DB_HOME/lib

• Script file to set environment variables in Linux/Mac

cd .../go_ibm_db/installer
source setenv.sh

• For Docker Linux Container, use below commands:

yum install -y gcc git go wget tar xz make gcc-c++
cd /root
curl -OL https://golang.org/dl/go1.21.4.linux-amd64.tar.gz
tar -C /usr/local -xzf go1.21.4.linux-amd64.tar.gz

rm /usr/bin/go
rm /usr/bin/gofmt
cp /usr/local/go/bin/go /usr/bin/
cp /usr/local/go/bin/gofmt /usr/bin/

go install github.com/ibmdb/go_ibm_db/installer@v0.4.5
or 
go install github.com/ibmdb/go_ibm_db/installer@latest

How to Install in z/OS

• You may install go_ibm_db using the below command

go install github.com/ibmdb/go_ibm_db/installer@latest

Configure ODBC driver on z/OS

Note You must have the following environment variables set.

• IBM_DB_HOME
• STEPLIB
• DSNAOINI

Please refer to the ODBC Guide and References cookbook for how to configure your ODBC driver. Specifically, you need to ensure you have:

1. Apply Db2 on z/OS PTF UI60551 to pick up new ODBC functionality to support Node.js applications.

2. Binded the ODBC packages. A sample JCL is provided in the SDSNSAMP dataset in member DSNTIJCL. Customize the JCL with specifics to your system.

3. Set the IBM_DB_HOME environment variable to the High Level Qualifier (HLQ) of your Db2 datasets. For example, if your Db2 datasets are located as DSNC10.SDSNC.H and DSNC10.SDSNMACS, you need to set IBM_DB_HOME environment variable to DSNC10 with the following statement (can be saved in ~/.profile):

   # Set HLQ to Db2 datasets.
   export IBM_DB_HOME="DSNC10"

4. Update the STEPLIB environment variable to include the Db2 SDSNEXIT, SDSNLOAD and SDSNLOD2 data sets. You can set the STEPLIB environment variable with the following statement, after defining IBM_DB_HOME to the high level qualifier of your Db2 datasets as instructed above:

   # Assumes IBM_DB_HOME specifies the HLQ of the Db2 datasets.
   export STEPLIB=$STEPLIB:$IBM_DB_HOME.SDSNEXIT:$IBM_DB_HOME.SDSNLOAD:$IBM_DB_HOME.SDSNLOD2

5. Configured an appropriate Db2 ODBC initialization file that can be read at application time. You can specify the file by using either a DSNAOINI data definition statement or by defining a DSNAOINI z/OS UNIX environment variable. For compatibility with ibm_db, the following properties must be set:

   In COMMON section:

   MULTICONTEXT=2
   CURRENTAPPENSCH=ASCII
   FLOAT=IEEE
   

   In SUBSYSTEM section:

   MVSATTACHTYPE=RRSAF
   

   Here is a sample of a complete initialization file:

   ; This is a comment line...
   ; Example COMMON stanza
   [COMMON]
   MVSDEFAULTSSID=VC1A
   CONNECTTYPE=1
   MULTICONTEXT=2
   CURRENTAPPENSCH=ASCII
   FLOAT=IEEE
   ; Example SUBSYSTEM stanza for VC1A subsystem
   [VC1A]
   MVSATTACHTYPE=RRSAF
   PLANNAME=DSNACLI
   ; Example DATA SOURCE stanza for STLEC1 data source
   [STLEC1]
   AUTOCOMMIT=1
   CURSORHOLD=1
   

Here's a simple script you can run setup your ODBC INI file. The following script exepcts that you have have defined your subsystem in following way:

export SUBSYSTEM=<SSID>

This script will setup your inistialization file.

export DSNAOINI="$HOME/ODBC_${HOSTNAME}_${SUBSYSTEM}_CAF"
touch $DSNAOINI
/bin/cat /dev/null  > "$DSNAOINI"
/bin/chtag -t -c 1047 "$DSNAOINI"
_BPXK_AUTOCVT=ON /bin/cat <<EOF >"$DSNAOINI"
[COMMON]
MVSDEFAULTSSID=$SUBSYSTEM
CURRENTAPPENSCH=UNICODE
FLOAT=IEEE
[$SUBSYSTEM]
MVSATTACHTYPE=CAF
PLANNAME=DSNACLI
[$HOSTNAME$SUBSYSTEM]
AUTOCOMMIT=1
EOF

Reference Chapter 3 in the [ODBC Guide and References](https://www.ibm.com/support/knowledgecenter/SSEPEK/pdf/db2z_12_odbcbook.pdf) for more instructions.

For z/OS and iSeries Connectivity and SQL1598N error

• Connection to Db2 for z/OS or Db2 for i(AS400) Server using ibm_db driver from distributed platforms (Linux, Unix, Windows and MacOS) is not free. It requires either client side or server side license.

• Connection to Db2 for LUW or Informix Server using ibm_db driver is free.

• ibm_db returns SQL1598N error in absence of a valid db2connect license. SQL1598N error is returned by the Db2 Server to client. To suppress this error, Db2 server must be activated with db2connectactivate utility OR a client side db2connect license file must exist.

• Db2connect license can be applied on database server or client side. A db2connect license of version 11.5 is required for ibm_db.

• For activating server side license, you can purchase either Db2 Connect Unlimited Edition for System z® or Db2 Connect Unlimited Edition for System i® license from IBM.

• Ask your DBA to run db2connectactivate utility on Server to activate db2connect license.

• If database Server is enabled for db2connect, no need to apply client side db2connect license.

• If Db2 Server is not db2connectactivated to accept unlimited number of client connection, you must need to apply client side db2connect license.

• db2connectactivate utility and client side db2connect license both comes together from IBM in a single zip file.

• Client side db2connect license is a db2con*.lic file that must be copied under clidriver\license directory.

• If you have a db2jcc_license_cisuz.jar file, it will not work for ibm_db. db2jcc_license_cisuz.jar is a db2connect license file for Java Driver. For non-Java Driver, client side db2connect license comes as a file name db2con*.lic.

• If environment variable IBM_DB_HOME or IBM_DB_INSTALLER_URL is not set, ibm_db automatically downloads open source driver specific clidriver and save as github.com/ibmdb/clidriver. Ignores any other installation.

• If IBM_DB_HOME or IBM_DB_INSTALLER_URL is set, you need to have same version of db2connect license as installed db2 client. Check db2 client version using db2level command to know version of db2connect license required. The license file should get copied under $IBM_DB_HOME\license directory.

• If you do not have db2connect license, contact IBM Customer Support to buy db2connect license. Find the db2con*.lic file in the db2connect license shared by IBM and copy it under .../github.com/ibmdb/clidriver/license directory or $IBM_DB_HOME/license directory if IBM_DB_HOME is set.

• To know more about license and purchasing cost, please contact IBM Customer Support.

• To know more about server based licensing viz db2connectactivate, follow below links:

• Activating the license certificate file for Db2 Connect Unlimited Edition.
• Unlimited licensing using db2connectactivate utility.

How to run sample program

example1.go:-

package main

import (
	"database/sql"
	"fmt"
	_ "github.com/ibmdb/go_ibm_db"
)

func main() {
	con := "HOSTNAME=host;DATABASE=name;PORT=number;UID=username;PWD=password"
	db, err := sql.Open("go_ibm_db", con)
	if err != nil {
		fmt.Println(err)
	}
	db.Close()
}

To run the sample:- go run example1.go

For complete list of connection parameters please check this.

example2.go:-

package main

import (
	"database/sql"
	"fmt"
	_ "github.com/ibmdb/go_ibm_db"
)

func Create_Con(con string) *sql.DB {
	db, err := sql.Open("go_ibm_db", con)
	if err != nil {
		fmt.Println(err)
		return nil
	}
	return db
}

// Creating a table.

func create(db *sql.DB) error {
	_, err := db.Exec("DROP table SAMPLE")
	if err != nil {
		_, err := db.Exec("create table SAMPLE(ID varchar(20),NAME varchar(20),LOCATION varchar(20),POSITION varchar(20))")
		if err != nil {
			return err
		}
	} else {
		_, err := db.Exec("create table SAMPLE(ID varchar(20),NAME varchar(20),LOCATION varchar(20),POSITION varchar(20))")
		if err != nil {
			return err
		}
	}
	fmt.Println("TABLE CREATED")
	return nil
}

// Inserting row.

func insert(db *sql.DB) error {
	st, err := db.Prepare("Insert into SAMPLE(ID,NAME,LOCATION,POSITION) values('3242','Mike','Hyderabad','Manager')")
	if err != nil {
		return err
	}
	st.Query()
	return nil
}

// This API selects the data from the table and prints it.

func display(db *sql.DB) error {
	st, err := db.Prepare("select * from SAMPLE")
	if err != nil {
		return err
	}
	err = execquery(st)
	if err != nil {
		return err
	}
	return nil
}

func execquery(st *sql.Stmt) error {
	rows, err := st.Query()
	if err != nil {
		return err
	}
	cols, _ := rows.Columns()
	fmt.Printf("%s    %s   %s    %s\n", cols[0], cols[1], cols[2], cols[3])
	fmt.Println("-------------------------------------")
	defer rows.Close()
	for rows.Next() {
		var t, x, m, n string
		err = rows.Scan(&t, &x, &m, &n)
		if err != nil {
			return err
		}
		fmt.Printf("%v  %v   %v   %v\n", t, x, m, n)
	}
	return nil
}

func main() {
	con := "HOSTNAME=host;DATABASE=name;PORT=number;UID=username;PWD=password"
	type Db *sql.DB
	var re Db
	re = Create_Con(con)
	err := create(re)
	if err != nil {
		fmt.Println(err)
	}
	err = insert(re)
	if err != nil {
		fmt.Println(err)
	}
	err = display(re)
	if err != nil {
		fmt.Println(err)
	}
}

To run the sample:- go run example2.go

example3.go:-(POOLING)

package main

import (
	_ "database/sql"
	"fmt"
	a "github.com/ibmdb/go_ibm_db"
)

func main() {
	// Defining connection string
	// Depending on your connection type
	// you may wish to add: MULTICONTEXT=0
	con := "HOSTNAME=host;PORT=number;DATABASE=name;UID=username;PWD=password"
	pool := a.Pconnect("PoolSize=100")

	// SetConnMaxLifetime will take the value in SECONDS
	db := pool.Open(con, "SetConnMaxLifetime=30")
	st, err := db.Prepare("Insert into SAMPLE values('hi','hi','hi','hi')")
	if err != nil {
		fmt.Println(err)
	}
	st.Query()

	// Here the time out is default.
	db1 := pool.Open(con)
	st1, err := db1.Prepare("Insert into SAMPLE values('hi1','hi1','hi1','hi1')")
	if err != nil {
		fmt.Println(err)
	}
	st1.Query()

	db1.Close()
	db.Close()
	pool.Release()
	fmt.Println("success")
}

To run the sample:- go run example3.go

example4.go:-(POOLING- Limit on the number of connections)

package main

import (
           "database/sql"
           "fmt"
           "time"
          a "github.com/ibmdb/go_ibm_db"
       )

func ExecQuery(st *sql.Stmt) error {
        res, err := st.Query()
        if err != nil {
             fmt.Println(err)
        }
        cols, _ := res.Columns()

        fmt.Printf("%s    %s   %s     %s\n", cols[0], cols[1], cols[2], cols[3])
        defer res.Close()
        for res.Next() {
                    var t, x, m, n string
                    err = res.Scan(&t, &x, &m, &n)
                    fmt.Printf("%v  %v   %v     %v\n", t, x, m, n)
        }
        return nil
}

func main() {
	con := "HOSTNAME=host;PORT=number;DATABASE=name;UID=username;PWD=password"
        pool := a.Pconnect("PoolSize=5")

        ret := pool.Init(5, con)
        if ret != true {
                fmt.Println("Pool initializtion failed")
        }

        for i:=0; i<20; i++ {
                db1 := pool.Open(con, "SetConnMaxLifetime=10")
                if db1 != nil {
                        st1, err1 := db1.Prepare("select * from VMSAMPLE")
                        if err1 != nil {
                                fmt.Println("err1 : ", err1)
                        }else{
                                go func() {
                                        ExecQuery(st1)
                                        db1.Close()
                                }()
                        }
                }
        }
        time.Sleep(30*time.Second)
        pool.Release()
}

To run the sample:- go run example4.go

For Running the Tests:

• Connection information must be specified in the environment variables

For example, by sourcing the following ENV variables:
export DB2_DATABASE=<Database Name>
export DB2_USER=<Username>
export DB2_PASSWD=<Password>
export DB2_HOSTNAME=<Hostname or IP>
export DB2_PORT=<Database Port>

• OR

If not using environment variables, update connection information in
go_ibm_db/testdata/config.json file.

• Now run go test command (use go test -v command for details)

• To run a particular test case (use "go test sample_test.go main.go", example "go test Arraystring_test.go main.go")