Being a Developer: December 2010

2010/12/30

Firebird C API - 질의문 수행 후 반영된 레코드 수 구하는 함수

struct AFFECTED_ROW
{
    int Insert;
    int Select;
    int Update;
    int Delete;

    AFFECTED_ROW()
    {
        Init();
    }

    void Init()
    {
        Insert = 0;
        Select = 0;
        Update = 0;
        Delete = 0;
    }
};


void CTestEFBDlg::GetAffectedRow( isc_stmt_handle stmt, AFFECTED_ROW& affected )
{
    static char const info_count[] = { isc_info_sql_records };
    char result[64] = { 0, };
    int ret = 0;

    ISC_STATUS_ARRAY    status;
    ISC_LONG            sqlcode;

    affected.Init();

    isc_dsql_sql_info( status, &stmt, sizeof(info_count), info_count, sizeof(result), result );

    if ( status[ 0 ] == 1 && status[ 1 ] > 0 )
    {
        // Error occurred
        sqlcode = isc_sqlcode( status );

        char szMsg[512];
        isc_sql_interprete( (short)sqlcode, szMsg, 512 );

        CString strMsg;
        strMsg.Format( _T("Fail to isc_dsql_sql_info : %d - %s"), sqlcode, CString( szMsg ) );
        AppendResult( strMsg );
    }
    else
    {
        char* pCur = result;
        int length;
        if ( *pCur == isc_info_sql_records ) 
        {
            pCur++;
            length = isc_vax_integer(pCur, 2);
            pCur += 2;

            while(*pCur != 1) 
            {
                switch(*pCur) 
                {
                case isc_info_req_select_count:
                    pCur++;
                    length = isc_vax_integer(pCur, 2);
                    pCur += 2;
                    affected.Select = isc_vax_integer(pCur, length);
                    pCur += length;
                    break;
                case isc_info_req_insert_count:
                    pCur++;
                    length = isc_vax_integer(pCur, 2);
                    pCur += 2;
                    affected.Insert = isc_vax_integer(pCur, length);
                    pCur += length;
                    break;
                case isc_info_req_update_count:
                    pCur++;
                    length = isc_vax_integer(pCur, 2);
                    pCur += 2;
                    affected.Update = isc_vax_integer(pCur, length);
                    pCur += length;
                    break;
                case isc_info_req_delete_count:
                    pCur++;
                    length = isc_vax_integer(pCur, 2);
                    pCur += 2;
                    affected.Delete = isc_vax_integer(pCur, length);
                    pCur += length;
                    break;
                default:
                    pCur++;
                    break;
                }
            }
        }
    }
}


GetAffectedRow( stmt, affected );

CString strMsg;
strMsg.Format( _T("%d Row(s) Updated"), affected.Update );
AfxMessageBox( strMsg );
<

Original Post : http://neodreamer-dev.tistory.com/481

2010/12/26

Firebird C API 질의문 수행 후 반영된 레코드 수 구하기

아래 코드는 isc_dsql_sql_info() 함수를 이용하여 질의문를 후행 한 후 반영된 레코드 수를 가져오는 코드 이다.

int del_count = 0, ins_count = 0, upd_count = 0, sel_count = 0;
static char const info_count[] = { isc_info_sql_records };
char result[64];
int ret = 0;

isc_dsql_sql_info( status, &stmt, sizeof(info_count), info_count, sizeof(result), result );

if ( status[ 0 ] == 1 && status[ 1 ] > 0 )
{
    // Error occurred
    sqlcode = isc_sqlcode( status );

    char szMsg[512];
    isc_sql_interprete( (short)sqlcode, szMsg, 512 );

    CString strMsg;
    strMsg.Format( _T("Fail to isc_dsql_sql_info : %d - %s"), sqlcode, CString( szMsg ) );
    AfxMessageBox( strMsg );
}
else
{
    char* pCur = result;
    int length;
    if ( *pCur == isc_info_sql_records ) 
    {
        pCur++;
        length = isc_vax_integer(pCur, 2);
        pCur += 2;

        while(*pCur != 1) 
        {
            switch(*pCur) 
            {
            case isc_info_req_select_count:
                pCur++;
                length = isc_vax_integer(pCur, 2);
                pCur += 2;
                sel_count = isc_vax_integer(pCur, length);
                pCur += length;
                break;

            case isc_info_req_insert_count:
                pCur++;
                length = isc_vax_integer(pCur, 2);
                pCur += 2;
                ins_count = isc_vax_integer(pCur, length);
                pCur += length;
                break;

            case isc_info_req_update_count:
                pCur++;
                length = isc_vax_integer(pCur, 2);
                pCur += 2;
                upd_count = isc_vax_integer(pCur, length);
                pCur += length;
                break;

            case isc_info_req_delete_count:
                pCur++;
                length = isc_vax_integer(pCur, 2);
                pCur += 2;
                del_count = isc_vax_integer(pCur, length);
                pCur += length;
                break;

            default:
                pCur++;
                break;
            }
        }

        CString strMsg;
        strMsg.Format( _T("%d Row(s) Updated"), upd_count );
        AfxMessageBox( strMsg );
    }
}

isc_info_sql_records 파라메터를 이용하여 isc_dsql_sql_info() 함수를 수행 한 후의 Request Buffer 내용

Result buffer for DELETE statement contains:
    23,  29,0,               (isc_info_sql_records, length=29)
    15,  4,0,  0,0,0,0,      (isc_info_req_update_count, 0 rows updated)
    16,  4,0,  4,0,0,0,      (isc_info_req_delete_count, 4 rows deleted)
    13,  4,0,  4,0,0,0,      (isc_info_req_select_count, 4 rows selected)
    14,  4,0,  0,0,0,0,      (isc_info_req_insert_count)
    1,                       (isc_info_end)

Result buffer for UPDATE statement contains:
    23,  29,0,
    15,  4,0,  4,0,0,0,
    16,  4,0,  0,0,0,0,
    13,  4,0,  4,0,0,0,
    14,  4,0,  0,0,0,0,
    1,

Result buffer for INSERT statement contains:
    23,  29,0,
    15,  4,0,  0,0,0,0,
    16,  4,0,  0,0,0,0,
    13,  4,0,  0,0,0,0,
    14,  4,0,  1,0,0,0,
    1,

isc_dsql_sql_info() 함수에 isc_info_sql_records 파라메터를 이용하여 데이터베이스에서 반영 된 레코드 수를 가져올 수 있는데 반영된 수가 누적되고 있다. 이에 대한 내용은 좀 더 분석을 해 보아야겠다. Firebird C API 의 경우 관련 자료가 많지 않아서 분석이 쉽지가 않다.

자료 출처

http://lua-sql.sourcearchive.com/documentation/2.2.0~rc1-1/ls__firebird_8c-source.html

http://www.ibase.ru/mail/RowsAffected.txt<

Original Post : http://neodreamer-dev.tistory.com/480

Firebird C API 간단 사용기

C API를 이용한 Firebird embedded 를 간단하게 사용하는 예이다. 질의문의 결과난 파라메터를 이용한 방법은 XSQLDA(eXtended SQL Descriptor Area)를 이해한 후에 정리를 해야 할 것 같다.

ClearResult();
AppendResult( _T("Try to attach database!!") );
isc_db_handle        db        = 0L;        /* database handle */
isc_tr_handle        trans    = NULL;        /* transaction handle */
isc_stmt_handle        stmt    = NULL;        /* statement handle */

char                szDBName[ MAX_PATH ] = "E:\TEST.FDB";
ISC_STATUS_ARRAY    status;
ISC_LONG            sqlcode;

// Database Parameter Block (DPB) 준비
std::string strDPB;

strDPB.append( 1, isc_dpb_version1 );        // DPB 버전
strDPB.append( 1, isc_dpb_user_name );        // User Account
strDPB.append( 1, (char)strlen("sysdba") );
strDPB.append( "sysdba" );
strDPB.append( 1, isc_dpb_password );        // Password
strDPB.append( 1, (char)strlen("masterkey") );
strDPB.append( "masterkey" );

// Database connect
if ( isc_attach_database( status, 0, szDBName, &db, (short)strDPB.length(), strDPB.c_str() ) )
{
    AppendResult( _T("Fail to attach database!!") );

    return;
}

// Start Transaction
isc_start_transaction( status, &trans, 1, &db, 0, NULL );

// Execute query
char szQuery[1024];

// Create Table
sprintf_s( szQuery, 1024,
    "CREATE TABLE employee ("
    "  name VARCHAR(20) "
    ", birth INTEGER"
    ", enter TIMESTAMP"
    ")");

isc_dsql_execute_immediate( status, &db, &trans, strlen(szQuery), szQuery, 1, NULL );
isc_commit_transaction( status, &trans );

if ( status[0] == 1 && status[ 1 ] > 0 )
{
    // Error occurred
    sqlcode = isc_sqlcode( status );

    char szMsg[512];
    isc_sql_interprete( (short)sqlcode, szMsg, 512 );

    CString strMsg;
    strMsg.Format( _T("Fail to Create Table : %d - %s"), sqlcode, CString( szMsg ) );
    AppendResult( strMsg );
}
else
{
    AppendResult( _T("Table Creaded.") );
}

// Insert Data
isc_start_transaction( status, &trans, 1, &db, 0, NULL );
AppendResult( _T("Insertion!!") );
for ( int i = 0;  i < 5; ++i )
{
    sprintf_s( szQuery, 1024,
        "INSERT INTO employee ( name, birth, enter ) VALUES ( 'name%d', %d, CURRENT_TIMESTAMP )"
        , i, 20 + i
        );

    isc_dsql_execute_immediate( status, &db, &trans, strlen(szQuery), szQuery, 1, NULL );

    if ( status[0] == 1 && status[ 1 ] > 0 )
    {
        // Error occurred
        sqlcode = isc_sqlcode( status );

        char szMsg[512];
        isc_sql_interprete( (short)sqlcode, szMsg, 512 );

        CString strMsg;
        strMsg.Format( _T("Fail to Insert : %d - %s"), sqlcode, CString( szMsg ) );
        AppendResult( strMsg );
    }
    else
    {
        AppendResult( _T("1 Row Inserted.") );
    }
}

// Update Data
// Statement allocation
isc_dsql_allocate_statement( status, &db, &stmt );

AppendResult( _T("Update!!") );
sprintf_s( szQuery, 1024, "UPDATE employee SET birth = birth + 2 WHERE birth > 22");

isc_dsql_prepare( status, &trans, &stmt, 0, szQuery, 0, NULL );

isc_dsql_execute( status, &trans, &stmt, 0, NULL );
isc_commit_transaction( status, &trans );

if ( status[ 0 ] == 1 && status[ 1 ] > 0 )
{
    // Error occurred
    sqlcode = isc_sqlcode( status );

    char szMsg[512];
    isc_sql_interprete( (short)sqlcode, szMsg, 512 );

    CString strMsg;
    strMsg.Format( _T("Fail to Update : %d - %s"), sqlcode, CString( szMsg ) );
    AppendResult( strMsg );
}
else
{
    AppendResult( _T("Table Updated") );
}

isc_dsql_free_statement( status, &stmt, DSQL_close );

// Delete Table
AppendResult( _T("Drop Table!!") );
sprintf_s( szQuery, 1024, "DROP TABLE employee");

isc_dsql_execute_immediate( status, &db, &trans, strlen(szQuery), szQuery, 1, NULL );

// Commit Transaction
isc_commit_transaction( status, &trans );

// Database disconnect
isc_detach_database( status, &db );

AppendResult( _T("Database detached!!") );
AppendResult( _T("Finished!!") );
<

Original Post : http://neodreamer-dev.tistory.com/479

2010/12/09

SQLite Release 3.7.4.0 (정적/동적 라이브러리 포함)

SQLite 가 버전업이 되었다. 3.7.2 버전 미만을 사용하고 있을경우 업그레이드를 권장하고 있다.

SQLite Release 3.7.4 On 2010 December 08 (3.7.4)

Added the sqlite3_blob_reopen() interface to allow an existing sqlite3_blob object to be rebound to a new row.

Use the new sqlite3_blob_reopen() interface to improve the performance of FTS.

VFSes that do not support shared memory are allowed to access WAL databases if PRAGMA locking_mode is set to EXCLUSIVE.

Enhancements to EXPLAIN QUERY PLAN.

Added the sqlite3_stmt_readonly() interface.

Added PRAGMA checkpoint_fullfsync.

Added the SQLITE_FCNTL_FILE_POINTER option to sqlite3_file_control().

Added support for FTS4 and enhancements to the FTS matchinfo() function.

Added the test_superlock.c module which provides example code for obtaining an exclusive lock to a rollback or WAL database.

Added the test_multiplex.c module which provides an example VFS that provides multiplexing (sharding) of a DB, splitting it over multiple files of fixed size.