How to make this to read from custom string the information
I would like to read Host,User,Password,Database from the custom string, how can i do that?
Also another problem here in code is that it show that is connected with ODBC , but it doesnt read anything from database
GetPrivateProfileStringA("SQL","Host","127.0.0.1",szServer2,sizeof(szServer2),SQL_PATH);
GetPrivateProfileStringA("SQL","User","sa",szUser,sizeof(szUser),SQL_PATH);
GetPrivateProfileStringA("SQL","Password","12345",szPassword,sizeof(szPassword),SQL_PATH);
GetPrivateProfileStringA("SQL","Database","DbName",szDatabase,sizeof(szDatabase),SQL_PATH);
BOOL SQLCONNECT::Connect()
{
SQLHENV env;
SQLHDBC dbc;
SQLHSTMT stmt;
SQLRETURN ret;
SQLSMALLINT columns;
int row = 0;
/* Allocate an environment handle */
SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &env);
/* We want ODBC 3 support */
SQLSetEnvAttr(env, SQL_ATTR_ODBC_VERSION, (void *)SQL_OV_ODBC3, 0);
/* Allocate a connection handle */
SQLAllocHandle(SQL_HANDLE_DBC, env, &dbc);
/* Connect to the DSN */
SQLDriverConnectW(dbc, NULL, L"DRIVER={SQL Server};SERVER=(local);DATABASE=DbName;UID=sa;PWD=password;", SQL_NTS, NULL, 0, NULL, SQL_DRIVER_COMPLETE);
/* Check for success */
if (SQL_SUCCESS != SQLAllocHandle(SQL_HANDLE_STMT, dbc, &stmt))
{
MessageBoxA(0, "Failed to connect to Database!", "Error", MB_OK);
}
std::cin.get();
return FALSE;
}
Related
connection to access is normal, the SQL query is executed, I get a SQL Success response. and I can't do it anymore. how to get data from sql query
int bdacess(int argc, char* argv[])
{
/* Allocate an environment handle */
rc = SQLAllocEnv(&hEnv);
/* Allocate a connection handle */
rc = SQLAllocConnect(hEnv, &hDbc);
/* Connect to the database */
rc = SQLDriverConnect(hDbc, NULL, (WCHAR*)szDSN, SQL_NTS, (WCHAR*)szConnStrOut, 255, (SQLSMALLINT*)&iConnStrLength2Ptr, SQL_DRIVER_NOPROMPT);
if (SQL_SUCCEEDED(rc))
{
wprintf(L"Successfully connected to database. Data source name: \n %s\n", szConnStrOut);
/* Prepare SQL query */
wprintf(L"SQL query:\n %s\n", query);
rc = SQLAllocStmt(hDbc, &hStmt);
rc = SQLPrepare(hStmt, query, SQL_NTS);
/* Excecute the query */
rc = SQLExecute(hStmt);
if (SQL_SUCCEEDED(rc))
{
wprintf(L"SQL Success\n");
}
else {
wprintf(L"SQL Failed\n");
}
}
else
{
wprintf(L"Couldn't connect to %s.\n", szDSN);
}
/* Disconnect and free up allocated handles */
SQLDisconnect(hDbc);
SQLFreeHandle(SQL_HANDLE_DBC, hDbc);
SQLFreeHandle(SQL_HANDLE_ENV, hEnv);
getchar();
return 0;
}
I can't get the result of sql execution itself
I have been trying to insert a row into my SQL table, i get no syntax error but unfortunately when i check my table in the SQL Server Management Studio, no new entry is added. When debugging, the retCode becomes less than zero starting from the SQLConnect() function.
int main()
{
SQLHANDLE SQLEnvHandle = NULL;
SQLHANDLE SQLConnectionHandle = NULL;
SQLHANDLE SQLStatementHandle = NULL;
SQLRETURN retCode = 0;
// Insert Query
char SQLQuery[] = "insert into crm.dbo.company_name values (22,'01 electronics','#01electronics.net');";
// SQL Server Identifier
char SQLServer[] = "DRIVER={SQL Server}; SERVER=localhost, 8000; DATABASE=xxxx; UID=xxxx_xxxx; PWD=xxxx;";
do
{
// Allocate environment
retCode = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &SQLEnvHandle);
// Set ODBC Version
retCode = SQLSetEnvAttr(SQLEnvHandle, SQL_ATTR_ODBC_VERSION,(SQLPOINTER*)SQL_OV_ODBC3, 0);
// Allocate Connection
retCode = SQLAllocHandle(SQL_HANDLE_DBC, SQLEnvHandle, &SQLConnectionHandle);
// Set Login Timeout
retCode = SQLSetConnectAttr(SQLConnectionHandle, SQL_LOGIN_TIMEOUT, (SQLPOINTER)5, 0);
// Set Auto Commit
retCode = SQLSetConnectAttr(SQLConnectionHandle, SQL_ATTR_AUTOCOMMIT, (SQLPOINTER)TRUE, 0);
// Connect to DSN
retCode = SQLConnect(SQLConnectionHandle, (SQLCHAR*) SQLServer, SQL_NTS, (SQLCHAR*)NULL, 0, NULL, 0);
// Allocate Statement Handle
retCode = SQLAllocHandle(SQL_HANDLE_STMT, SQLConnectionHandle, &SQLStatementHandle);
// Prepare Statement
retCode = SQLPrepare(SQLStatementHandle, (SQLCHAR*)SQLQuery, SQL_NTS);
// Execute Statement
if (SQLExecute(SQLStatementHandle) == SQL_SUCCESS || SQLExecute(SQLStatementHandle) == SQL_SUCCESS_WITH_INFO)
cout << "SUCCESS";
else
cout << "FAILURE";
} while (FALSE);
// Frees the resources and disconnects
SQLFreeHandle(SQL_HANDLE_STMT, SQLStatementHandle);
SQLDisconnect(SQLConnectionHandle);
SQLFreeHandle(SQL_HANDLE_DBC, SQLConnectionHandle);
SQLFreeHandle(SQL_HANDLE_ENV, SQLEnvHandle);
getchar();
}
When debugging, the retCode becomes less than zero starting from the SQLConnect() function.
From the docs:
When SQLConnect returns SQL_ERROR or SQL_SUCCESS_WITH_INFO, an
associated SQLSTATE value can be obtained by calling SQLGetDiagRec
with a HandleType of SQL_HANDLE_DBC and a Handle of ConnectionHandle
I have the following code (using ODBC to connect to an SQL database):
The connection is OK and also the first SQL_ExecuteQuery(), but the second and third SQL_ExecuteQuery() will return with an error (returncode -1 for SQLExecDirect).
I assume, that the "statement handle hstmt" will be overwritten after the first execution. But how can I avoid this? Thank you so much.
SQLHENV henv = SQL_NULL_HENV;
SQLHDBC hdbc = SQL_NULL_HDBC;
SQLHDBC hstmt= SQL_NULL_HSTMT;
SQLRETURN retcode = SQL_SUCCESS;
//Connect function
int SQL_Connect()
{
SQLWCHAR OutConnStr[255];
SQLSMALLINT OutConnStrLen;
// Allocate environment handle
retcode = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv);
// Set the ODBC version environment attribute
if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO)
{
retcode = SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, (SQLPOINTER*)SQL_OV_ODBC3, 0);
// Allocate connection handle
if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO)
{
retcode = SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);
// Set login timeout to 5 seconds
if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO)
{
SQLSetConnectAttr(hdbc, SQL_LOGIN_TIMEOUT, (SQLPOINTER)5, 0);
retcode = SQLDriverConnect( hdbc,
NULL,
#ifdef IPC
(SQLWCHAR *)L"DSN=TEST;Description=ODK;UID=FFF;PWD=XXX;Trusted_Connection=No;DATABASE=DDD;",
#else
(SQLWCHAR *)L"DSN=ODKSQL64;Description=ODK;UID=auto;PWD=Visu_KDbos;Trusted_Connection=No;DATABASE=Giesserei_BKO;",
#endif
SQL_NTS,
OutConnStr,
255,
&OutConnStrLen,
SQL_DRIVER_NOPROMPT);
// Allocate statement handle
if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO)
{
retcode = SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt);
cout<<"Verbindung OK"<<std::endl;
}
}
}
}
return retcode;
}
//Disonnect function
int SQL_Disconnect ()
{
SQLFreeHandle(SQL_HANDLE_STMT, hstmt );
SQLDisconnect(hdbc);
SQLFreeHandle(SQL_HANDLE_DBC, hdbc);
SQLFreeHandle(SQL_HANDLE_ENV, henv);
return 1;
}
//Query function
int SQL_ExecuteQuery()
{
short rc;
char material[50];
SQLINTEGER strlenmaterial;
//prepare query
std::wstring SQL_Statement = L"SELECT blablabla";
rc = SQLExecDirect(hstmt, const_cast<SQLWCHAR*>(SQL_Statement.c_str()), SQL_NTS);
if (rc==SQL_SUCCESS || rc==SQL_SUCCESS_WITH_INFO) {
SQLBindCol(hstmt, 1, SQL_C_CHAR, &material, (SQLINTEGER) sizeof(material), &strlenmaterial);
while (1) {
rc = SQLFetch(hstmt);
if (rc==SQL_SUCCESS || rc==SQL_SUCCESS_WITH_INFO) {
rc = 1;
}else {
break;
}
}
} else {
//no data found
rc = 3;
}
return rc;
}
int main()
{
short rc;
rc = SQL_Connect();
rc = SQL_ExecuteQuery();
rc = SQL_ExecuteQuery();
rc = SQL_ExecuteQuery();
rc = SQL_Disconnect();
return 0;
}
You can re-use a HSTMT handle, but before running a new query, you need to close the pending cursor. As you are binding the columns using SQLBindCol, you also need to unbind the columns, before binding them again.
In your SQL_ExecuteQuery(), before returning from the function call:
SQLFreeStmt(hstmt, SQL_UNBIND)
SQLFreeStmt(hstmt, SQL_CLOSE)
Now you are ready to execute another query, bind again and fetch the result.
Note that you could also change the logic of your program, and bind only once, and then skip the unbind-step: If you know that you are always interested in the result of the same column, you could bind the column before executing the query. You can then execute the query, read the result, call SQLFreeStmt with the SQL_CLOSE option and start over with executing the query.
See here for more details:
https://learn.microsoft.com/en-us/sql/odbc/reference/syntax/sqlfreestmt-function
I am trying to read a large object from a PostgreSQL database using ODBC from Visual Studio C++. I can't get it to work.
The driver is PostgresSQL ANSI(x64) 9.50.04.00.
The data type of the column is lo, created with:
CREATE DOMAIN lo AS oid;
The column contains the object ids of the large objects.
My understanding is that when the driver sees a lo type, it will handle it as SQL_LONGVARBINARY.
However, the query fails. The diagnostics message is:
HY003 [Microsoft][OBDC Driver Manager] Program type out of range
Here is the code with the noise removed:
wchar_t* connect0 = L"DSN=picdb;";
SQLHENV env;
SQLHDBC dbc;
SQLHSTMT stmt;
SQLLEN sqllen = -1;
PBYTE image = new BYTE[0];
SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &env);
SQLSetEnvAttr(env, SQL_ATTR_ODBC_VERSION, (void *)SQL_OV_ODBC3, 0);
SQLAllocHandle(SQL_HANDLE_DBC, env, &dbc);
SQLDriverConnect(dbc, NULL, connect0, SQL_NTS, NULL, 0, NULL, SQL_DRIVER_COMPLETE);
SQLAllocHandle(SQL_HANDLE_STMT, dbc, &stmt);
SQLExecDirect(stmt, L"select lo from image_list where id=964945", SQL_NTS);
SQLFetch(stmt);
SQLGetData(stmt, 1, SQL_LONGVARBINARY, image, 0, &sqllen); //<----- It fails here
image = new BYTE[sqllen];
SQLGetData(stmt, 1, SQL_LONGVARBINARY, image, sqllen, &sqllen);
SQLDisconnect(dbc);
SQLFreeHandle(SQL_HANDLE_DBC, dbc);
SQLFreeHandle(SQL_HANDLE_ENV, env);
I can read regular data from the database just fine. And I can read the BLOB data from the database with Java/JDBC, but I need it to work in C++.
Why do I get the error, and what can I do to fix it?
This seems to work:
wchar_t* connect0 = L"DSN=picdb;";
SQLHENV env;
SQLHDBC dbc;
SQLHSTMT stmt;
SQLLEN sqllen = -1;
PBYTE image = new BYTE[0];
SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &env);
SQLSetEnvAttr(env, SQL_ATTR_ODBC_VERSION, (void *)SQL_OV_ODBC3, 0);
SQLAllocHandle(SQL_HANDLE_DBC, env, &dbc);
SQLDriverConnect(dbc, NULL, connect0, SQL_NTS, NULL, 0, NULL, SQL_DRIVER_COMPLETE);
SQLAllocHandle(SQL_HANDLE_STMT, dbc, &stmt);
SQLExecDirect(stmt, L"select lo from image_list where id=964945", SQL_NTS);
SQLFetch(stmt);
SQLGetData(stmt, 1, SQL_C_BINARY, image, 0, &sqllen);
image = new BYTE[sqllen];
SQLBindParameter(stmt, 1, SQL_PARAM_OUTPUT, SQL_C_BINARY, SQL_LONGVARBINARY, 0, 0, image, sqllen, NULL );
SQLGetData(stmt, 1, SQL_C_BINARY, image, sqllen, &sqllen);
SQLDisconnect(dbc);
SQLFreeHandle(SQL_HANDLE_DBC, dbc);
SQLFreeHandle(SQL_HANDLE_ENV, env);
We create and cache ODBC connections created using SQLDriverConnect; we've found circumstances where the connection becomes lost... prepared statements stop working, etc.
I didn't see an obvious function to test a connection/statement is valid, or to reset/re-create a connection, which seems like it would be a fairly common pattern. Can anyone suggest how this is best implemented?
This answer is along the same lines, is that the correct solution here too? If so is there any neat way to 're-boot' an existing statement to use the new connection? And if a connection is discovered to be dead does it still need to be freed?
In my mind there has always been some confusion over whether SQL_ATTR_CONNECTION_DEAD works to test if a connection is still alive before you make a call which requires it to be alive. This is based on the usage of many ODBC drivers, including the ones I wrote and I suspect they may all implement it differently.
In the post you refer to Nick's answer (SQL_ATTR_CONNECTION_DEAD) does not work with many drivers I have access to:
#include <stdio.h>
#include <sql.h>
#include <sqlext.h>
#include <stdlib.h>
static void extract_error(
char *fn,
SQLHANDLE handle,
SQLSMALLINT type);
main() {
SQLHENV henv;
SQLHDBC hdbc;
SQLHSTMT hstmt;
SQLCHAR outstr[1024];
SQLSMALLINT outstr_len;
SQLRETURN ret;
SQLINTEGER dead;
SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv);
SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, (void *) SQL_OV_ODBC3, 0);
SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);
ret = SQLDriverConnect(hdbc, (void *)0, "DSN=xx;UID=xx;PWD=xx", SQL_NTS,
outstr, sizeof(outstr), &outstr_len,
SQL_DRIVER_COMPLETE);
if (!SQL_SUCCEEDED(ret)) {
extract_error("SQLDriverConnect", hdbc, SQL_HANDLE_DBC);
exit(1);
}
SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt);
ret = SQLPrepare(hstmt, "select 123", SQL_NTS);
if (!SQL_SUCCEEDED(ret)) {
extract_error("SQLPrepare", hstmt, SQL_HANDLE_STMT);
exit(1);
}
ret = SQLExecute(hstmt);
if (!SQL_SUCCEEDED(ret)) {
extract_error("SQLExecute", hstmt, SQL_HANDLE_STMT);
exit(1);
}
sleep(120);
SQLGetConnectAttr(hdbc, SQL_ATTR_CONNECTION_DEAD, &dead, 0, NULL);
printf ("dead=%ld\n", dead);
ret = SQLExecute(hstmt);
if (!SQL_SUCCEEDED(ret)) {
extract_error("SQLExecute", hstmt, SQL_HANDLE_STMT);
}
SQLGetConnectAttr(hdbc, SQL_ATTR_CONNECTION_DEAD, &dead, 0, NULL);
printf ("dead=%ld\n", dead);
}
static void extract_error(
char *fn,
SQLHANDLE handle,
SQLSMALLINT type)
{
SQLINTEGER i = 0, native;
SQLCHAR state[ 7 ];
SQLCHAR text[256];
SQLSMALLINT len;
int ret;
fprintf(stderr,
"\n"
"The driver reported the following diagnostics whilst running "
"%s\n\n",
fn);
do
{
ret = SQLGetDiagRec(type, handle, ++i, state, &native, text,
sizeof(text), &len );
if (SQL_SUCCEEDED(ret))
printf( "%s:%ld:%ld:%s\n", state, i, native, text );
}
while( ret == SQL_SUCCESS );
}
which outputs with a number of drivers:
dead=0
# At this point I took the server down
The driver reported the following diagnostics whilst running SQLExecute
08S01:1:0:[SQL Server Driver 10.0][SQL Server]Communication link failure: short write
dead=0
The other option specified in the post you refer to is SQL_COPT_SS_CONNECTION_DEAD but that is specific to MS SQL Server.
Since I presume you don't intend for any statement handles to fail ordinarily can't you just run the stmt and if it fails assume the connection is dead and reconnect and reprepare?
If a connection does die you do still need to call SQLFreeHandle for the various handles.