一、编写代码
注：以下代码来自OTL示例，略有改动
#includeusing namespacestd;
#include
#include
#include#define OTL_ODBC //Compile OTL 4.0/ODBC
//The following #define is required with MyODBC 3.51.11 and higher
#define OTL_ODBC_SELECT_STM_EXECUTE_BEFORE_DESCRIBE
#define OTL_ODBC_UNIX //uncomment this line if UnixODBC is used#include//include the OTL 4.0 header file
otl_connect db; //connect object
voidinsert()//insert rows into table
{
otl_stream o(1, //buffer size should be == 1 always on INSERT
"insert into test_tab values"
"(:f1,:f2),"
"(:f12,:f22),"
"(:f13,:f23),"
"(:f14,:f24),"
"(:f15,:f25)",//INSERT statement. Multiple sets of values can be used//to work around the lack of the bulk interface
db //connect object
);//If the number of rows to be inserted is not known in advance,//another stream with the same INSERT can be opened
otl_stream o2(1, //buffer size should be == 1 always on INSERT
"insert into test_tab values"
"(:f1,:f2)", db //connect object
);char tmp[32];inti;for (i = 1; i <= 100; ++i) {
sprintf(tmp,"Name%d", i);
o<< i <
}for (i = 101; i <= 103; ++i) {
sprintf(tmp,"Name%d", i);
o2<< i <
}
}void update(const intaf1)//insert rows into table
{
otl_stream o(1, //buffer size should be == 1 always on UPDATE
"UPDATE test_tab"
"SET f2=:f2"
"WHERE f1=:f1",//UPDATE statement
db //connect object
);
o<< "Name changed" <
o<< otl_null() << af1 + 1; //set f2 to NULL
}void select(const intaf1) {
otl_stream i(50, //buffer size may be > 1
"select * from test_tab"
"where f1>=:f11"
"and f1<=:f12*2",//SELECT statement
db //connect object
);//create select stream
intf1;char f2[31];
i<< af1 << af1; //:f11 = af1, :f12 = af1
while (!i.eof()) { //while not end-of-data
i >>f1;
cout<< "f1=" << f1 << ", f2=";
i>>f2;if(i.is_null())
cout<< "NULL";elsecout<
cout<
}
}intmain() {
otl_connect::otl_initialize();//initialize ODBC environment
try{//db.rlogon("UID=xuanyuan;PWD=xuanyuan;DSN=examples");//connect to ODBC
//其中dsn是odbc连接的名字，不是数据库的名字，otl是通过odbc的名字找到数据库的， //而这个名字对于的配置里面,已经包含了IP,端口等信息，只要你提供用户名和密码就可以访问了"xuanyuan/xuanyuan@examples"); //connect to ODBC, alternative format of connect string
otl_cursor::direct_exec(db,"use examples"); //此行在原示例代码中没有，必须使用use xxx切换数据库
otl_cursor::direct_exec(db, "drop table test_tab",
otl_exception::disabled//disable OTL exceptions
); //drop table
otl_cursor::direct_exec(db,"create table test_tab(f1 int, f2 varchar(30)) type=innoDB"); //create table
insert();//insert records into the table
update(10); //update records in the table
select(8); //select records from the table
}catch (otl_exception& p) { //intercept OTL exceptions
cerr << p.msg << endl; //print out error message
cerr << p.stm_text << endl; //print out SQL that caused the error
cerr << p.sqlstate << endl; //print out SQLSTATE message
cerr << p.var_info << endl; //print out the variable that caused the error
}
db.logoff();//disconnect from ODBC
return 0;
}
二、编译代码
g++ -o"otl_test2" otl_test2.cpp -lmyodbc3
三、运行程序 otl_test
$ ./otl_test2
结果如下：
f1=8, f2=Name8
f1=9, f2=Name9
f1=10, f2=Name changed
f1=11, f2=NULL
f1=12, f2=Name12
f1=13, f2=Name13
f1=14, f2=Name14
f1=15, f2=Name15
f1=16, f2=Name16
