cli

import "github.com/asifjalil/cli"

Overview
Index
Examples

Overview

Package cli provides access to a DB2 database using DB2 Call Level Interface (CLI) API. This requires cgo and DB2 cli/odbc driver libdb2.so. It is not possible to use this driver to create a statically linked Go package because IBM doesn't provide the DB2 cli/odbc driver as libdb2.a static library. On Windows, DB2 cli/odbc library is not compatiable with gcc, but cgo requires gcc. Hence, this driver is not supported on Windows.

cli is based on alexbrainman's odbc package: https://github.com/alexbrainman/odbc.

This package registers a driver for the standard Go database/sql package and used through the database/sql API.

import _ "github.com/asifjalil/cli"

Error Handling

The package has no exported API except two functions-SQLCode() and SQLState()-for inspecting DB2 CLI error. The function signature is as follows:

func (e *cliError) SQLCode() int
func (e *cliError) SQLState() string

Since package cli is imported for side-effects only, use the following code pattern to access SQLCode() and SQLState():

func checkError(err error) {
    type sqlcode interface {
        SQLCode() int
    }
    if err != nil {
        if err, ok := err.(sqlcode); ok {
            log.Println(err.SQLCode())
        }
        log.Fatal(err)
    }
}

The local interface can include SQLState() also for inspecting SQLState from DB2 CLI.

SQLCODE is a return code from a IBM DB2 SQL operation. This code can be zero (0), negative, or positive.

0 means successful execution.
Negative means unsuccessful execution with an error.
For example -911 means a lock timeout occurred with a rollback.
Positive means successful execution with a warning.
For example +100 means no rows found or end of table.

Search "SQL messages" in DB2 Information Center to find out more about SQLCODE.

SQLSTATE is a return code like SQLCODE. But instead of a number, it is a five character error code that is consistent across all IBM database products. SQLSTATE follows this format: ccsss, where cc indicates class and sss indicates subclass. Search "SQLSTATE Messages" in DB2 Information Center for more detail.

Connection String

This driver uses DB2 CLI function SQLConnect and SQLDriverConnect in driver.Open(...). To use SQLConnect, start the name or the DSN string with keyword sqlconnect. This keyword is case insensitive. The connection string needs to follow this syntax to be valid:

"sqlconnect;[DATABASE=<database_name>;][UID=<user_id>;][PWD=<password>;]"

[...] means optional. If a database_name is not provided, then SAMPLE is used as the database name. Also note that each keyword and value ends with a semicolon. The keyword "sqlconnect" doesn't take a value but ends with a semi-colon. Examples:

db, err := sql.Open("cli", "sqlconnect;")
db, err := sql.Open("cli", "sqlconnect; DATABASE=\"SAMPLE\";")

Any other connection string must follow the connection string rule that is valid with SQLDriverConnect. For example, this is a valid dsn/connection string for SQLDriverConnect:

"DSN=Sample; UID=asif; PWD=secrect; AUTOCOMMIT=0; CONNECTTYPE=1;"

Examples:

db, err := sql.Open("cli", "DSN=Sample; UID=asif; PWD=secrect; AUTOCOMMIT=0; CONNECTTYPE=1;")
db, err := sql.Open("cli", "DATABASE=db; HOSTNAME=dbhost; PORT=40000; PROTOCOL=TCPIP; UID=me; PWD=secret;")

Search SQLDriverConnect in DB2 LUW Information Center for more detail.

Installation

IBM DB2 for Linux, Unix and Windows (DB2 LUW) implements its own ODBC driver. This package uses the DB2 ODBC/CLI driver through cgo. As such this package requires DB2 C headers and libraries for compilation. If you don't have DB2 LUW installed on the system, then you can install the free, community DB2 version DB2 Express-C. You can also use IBM Data Server Driver package. It includes the required headers and libraries but not a DB2 database manager.

To install, download this package by running the following: