使用CLI訪問DB2數據庫

這裏所說的CLI指的是DB2 Call Level Interface

代碼：

#include <stdio.h> 
#include <string.h> 
#include <sqlcli1.h> 

int main() 
{
	// Declare The Local Memory Variables 
	SQLHANDLE EnvHandle = 0; 
	SQLHANDLE ConHandle = 0; 
	SQLHANDLE StmtHandle = 0; 
	SQLRETURN RetCode = SQL_SUCCESS; 

	SQLCHAR  SQLStmt[255]; 
	SQLCHAR  JobType[10]; 
	SQLCHAR  EmpNo[10]; 
	SQLCHAR  LastName[25]; 

	/*-----------------------------------------------------*/ 
	/* INITIALIZATION                   */ 
	/*-----------------------------------------------------*/ 

	// Allocate An Environment Handle 
	SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, 
				&EnvHandle); 

	// Set The ODBC 應用程序 Version To 3.x 
	if (EnvHandle != 0) 
	  SQLSetEnvAttr(EnvHandle, SQL_ATTR_ODBC_VERSION, 
				  (SQLPOINTER) SQL_OV_ODBC3, SQL_IS_UINTEGER); 

	// Allocate A Connection Handle 
	if (EnvHandle != 0) 
	  SQLAllocHandle(SQL_HANDLE_DBC, EnvHandle, 
				  &ConHandle); 

	// Connect To The Appropriate Data Source 
	if (ConHandle != 0) 
	  RetCode = SQLConnect(ConHandle, (SQLCHAR *) "SAMPLE",  /*db2樣例數據庫，db2sampl程序可建立它*/
				  SQL_NTS, (SQLCHAR *) "db2inst1",         /*你的用戶名*/
				  SQL_NTS, (SQLCHAR *) "yourpasswd",   /*你的密碼*/
				  SQL_NTS); 

	/*-----------------------------------------------------*/ 
	/* TRANSACTION PROCESSING               */ 
	/*-----------------------------------------------------*/ 

	// Allocate An SQL Statement Handle 
	if (ConHandle != 0 && RetCode == SQL_SUCCESS) 
	  SQLAllocHandle(SQL_HANDLE_STMT, ConHandle, 
				  &StmtHandle); 

	// Define A SELECT SQL Statement That Uses A Parameter 
	// Marker 
	strcpy((char *) SQLStmt, "SELECT empno, lastname FROM "); 
	strcat((char *) SQLStmt, "employee WHERE job = ?"); 

	// Prepare The SQL Statement 
	RetCode = SQLPrepare(StmtHandle, SQLStmt, SQL_NTS); 

	// Bind The Parameter Marker Used In The SQL Statement To 
	// An Application Variable 
	RetCode = SQLBindParameter(StmtHandle, 1, 
				SQL_PARAM_INPUT, SQL_C_CHAR, SQL_CHAR, 
				sizeof(JobType), 0, JobType, 
				sizeof(JobType), NULL); 

	// Populate The "Bound" Application Variable 
	strcpy((char *) JobType, "DESIGNER"); 

	// Execute The SQL Statement 
	RetCode = SQLExecute(StmtHandle); 

	// If The SQL Statement Executed Successfully, Retrieve 
	// The Results 
	if (RetCode == SQL_SUCCESS) 
	{ 
		// Bind The Columns In The Result Data Set Returned 
		// To Application Variables 
		SQLBindCol(StmtHandle, 1, SQL_C_CHAR, (SQLPOINTER) 
					EmpNo, sizeof(EmpNo), NULL); 

		SQLBindCol(StmtHandle, 2, SQL_C_CHAR, (SQLPOINTER) 
					LastName, sizeof(LastName), NULL); 

		// While There Are Records In The Result Data Set 
		// Produced, Retrieve And Display Them 
		while (RetCode != SQL_NO_DATA) 
		{ 
			RetCode = SQLFetch(StmtHandle); 
			if (RetCode != SQL_NO_DATA) 
			  printf("%-8s %sn", EmpNo, LastName); 
		} 
	} 

	// Commit The Transaction 
	RetCode = SQLEndTran(SQL_HANDLE_DBC, ConHandle, SQL_COMMIT); 

	// Free The SQL Statement Handle 
	if (StmtHandle != 0) 
	  SQLFreeHandle(SQL_HANDLE_STMT, StmtHandle); 

	/*-----------------------------------------------------*/ 
	/* TERMINATION                     */ 
	/*-----------------------------------------------------*/ 

	// Terminate The Data Source Connection 
	if (ConHandle != 0) 
	  RetCode = SQLDisconnect(ConHandle); 

	// Free The Connection Handle 
	if (ConHandle != 0) 
	  SQLFreeHandle(SQL_HANDLE_DBC, ConHandle); 

	// Free The Environment Handle 
	if (EnvHandle != 0) 
	  SQLFreeHandle(SQL_HANDLE_ENV, EnvHandle); 

	// Return Control To The Operating System 
	return(0); 
}

編譯運行：

$ gcc -o db2test db2test.c -I/home/db2inst1/sqllib/include -L/home/db2inst1/sqllib/lib  -ldb2
$ ./db2test 
000150   ADAMSONn000160   PIANKAn000170   YOSHIMURAn000180   SCOUTTENn000190   WALKERn000200   BROWNn000210   JONESn000220   LUTZn200170   YAMAMOTOn200220   JOHNn