[IMPALA-1792] ImpalaODBC: Can not get the value in the SQLGetData(m-x th column) after the SQLBindCol(m th column)

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Invalid
• Affects Version/s: Impala 2.1
• Component/s: Clients
• Labels: correctness downgraded impala odbc
• Environment: OS: CentOS release 6.4 (Final); Impala: 2.1.0; ImpalaODBC: 2.5.23
• Target Version: Product Backlog
• Assignee: Unassigned
• Reporter: Mitsuhiro Koga
• Created: 17/Feb/15 09:37
• Updated: 30/Nov/20 19:58
• Resolved: 19/Jun/18 17:45

Description

Steps to reproduce

1. Create table and insert data in impala.

   create table t (c1 string, c2 string, c3 string);
   insert into t (c1, c2, c3) values ('AAA', 'BBB', 'CCC');
   

2. Query the t table with the following code.

   #include <stdio.h>
   #include <string.h>
   #include <sql.h>
   #include <sqlext.h>
   
   int main() {
       SQLHENV env;
       SQLHDBC dbc;
       SQLHSTMT stmt;
       SQLRETURN ret;
   
       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, (SQLCHAR*)NULL, (SQLCHAR*)"DSN=Impala", SQL_NTS, NULL, 0, NULL, SQL_DRIVER_COMPLETE);
       SQLAllocHandle(SQL_HANDLE_STMT, dbc, &stmt);
       SQLExecDirect(stmt, (SQLCHAR*)"select c1, c2, c3 from t", SQL_NTS);
   
       char szCol1[11];
       char szCol2[11];
       char szCol3[11];
       SQLLEN nColLen1;
       SQLLEN nColLen2;
       SQLLEN nColLen3;
   
       /*************************/
       /**** Bind 2nd column ****/
       /*************************/
       SQLBindCol(stmt, 2, SQL_C_CHAR, szCol2, sizeof(szCol2), &nColLen2);
   
       ret = SQLFetch(stmt);
       if (ret == SQL_SUCCESS || ret == SQL_SUCCESS_WITH_INFO) {
   
           /************************/
           /**** Get 1st column ****/
           /************************/
           ret = SQLGetData(stmt, 1, SQL_C_CHAR, szCol1, sizeof(szCol1), &nColLen1);
   
           if (ret == SQL_SUCCESS || ret == SQL_SUCCESS_WITH_INFO) {
               printf("c1: %s\n", szCol1);
           } else {
               printf("no data\n");
           }
   
           printf("c2: %s\n", szCol2);
   
           /************************/
           /**** Get 3rd column ****/
           /************************/
           ret = SQLGetData(stmt, 3, SQL_C_CHAR, szCol3, sizeof(szCol3), &nColLen3);
   
           if (ret == SQL_SUCCESS || ret == SQL_SUCCESS_WITH_INFO) {
               printf("c3: %s\n", szCol3);
           } else {
               printf("no data\n");
           }
       } else {
           printf("no row\n");
       }
   
       return 0;
   }
   

Expected result

c1: AAA
c2: BBB
c3: CCC

Actual result

no data
c2: BBB
c3: CCC