Description:
For mysql odbc connector, when fetching time type column bind to SQL_C_CHAR the returned string is incorrect if SSPS is enabled and hour has 3 digits.
In mysql, the TIME values may range from '-838:59:59' to '838:59:59'. However, mysql odbc connector doesn't format it correctly to C-char if SSPS is enabled.
For example, the last digits of seconds are lost for corner-case values '-838:59:59', '838:59:59'.
How to repeat:
The program bellow prints different output in default SSPS enabled mode then in NO_SSPS mode.
On mysql database create table with TIME type and corner case values.
CREATE TABLE time_tab (typetime TIME(0));
INSERT INTO time_tab VALUES ('-838:59:59'), ('838:59:59');
Run the following code
#include <sql.h>
#include <sqlext.h>
#include <stdio.h>
#define CONNECTION_STRING "..."
#define CONNECTION_STRING_LEN sizeof(CONNECTION_STRING)
#define BUFF_SIZE 256
int main() {
SQLHENV h_env = NULL;
SQLHDBC h_dbc = NULL;
SQLHSTMT h_stmt = NULL;
SQLLEN i_text_len = 0;
SQLSMALLINT i_out_connection_string_len = 0;
char psz_txt_buff[BUFF_SIZE];
int ret = 0;
SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &h_env);
SQLSetEnvAttr( h_env, SQL_ATTR_ODBC_VERSION, (void *) SQL_OV_ODBC3, 0 );
SQLAllocHandle(SQL_HANDLE_DBC, h_env, &h_dbc);
SQLDriverConnect(h_dbc, NULL, CONNECTION_STRING, CONNECTION_STRING_LEN, NULL, 0, &i_out_connection_string_len, SQL_DRIVER_NOPROMPT);
SQLAllocHandle(SQL_HANDLE_STMT, h_dbc, &h_stmt);
SQLPrepare(h_stmt, "SELECT typetime FROM time_tab;", SQL_NTS);
SQLBindCol(h_stmt, 1, SQL_C_CHAR, &psz_txt_buff, sizeof(psz_txt_buff), &i_text_len);
SQLExecute(h_stmt);
do {
ret = SQLFetch(h_stmt);
if (ret == SQL_SUCCESS || ret == SQL_SUCCESS_WITH_INFO)
printf("text='%s' len=%ld\n", psz_txt_buff, i_text_len);
} while (ret == SQL_SUCCESS);
}
If the connection is in SSPS disabled mode (NO_SSPS=1; in connection string), then this code prints as expected:
text='-838:59:59' len=10
text='838:59:59' len=9
When SSPS is enabled then the last characters are lost:
text='-838:59:5' len=9
text='838:59:5' len=8
Suggested fix:
The program should print same output regardless of if SSPS is enabled or not.
I think the issue is with the source code of mysql-connector-odbc, in file driver/my_prepared_stmt.cc, function fetch_varlength_columns.
The following code doesn't take into account that hour value for mysql can have 3 digits.
case MYSQL_TYPE_TIME:
{
MYSQL_TIME * t = (MYSQL_TIME *)(col_rbind->buffer);
buffer= ALLOC_IFNULL(buffer, 20);
myodbc_snprintf(buffer, 10, "%s%02u:%02u:%02u", t->neg? "-":"", t->hour,
t->minute, t->second);
*length= t->neg ? 9 : 8;
if (t->second_part > 0)
{
myodbc_snprintf(buffer+*length, 8, ".%06lu", t->second_part);
*length+= 7;
}
return buffer;
}
The length and buffers are too small if t->hour >= 100.
Description: For mysql odbc connector, when fetching time type column bind to SQL_C_CHAR the returned string is incorrect if SSPS is enabled and hour has 3 digits. In mysql, the TIME values may range from '-838:59:59' to '838:59:59'. However, mysql odbc connector doesn't format it correctly to C-char if SSPS is enabled. For example, the last digits of seconds are lost for corner-case values '-838:59:59', '838:59:59'. How to repeat: The program bellow prints different output in default SSPS enabled mode then in NO_SSPS mode. On mysql database create table with TIME type and corner case values. CREATE TABLE time_tab (typetime TIME(0)); INSERT INTO time_tab VALUES ('-838:59:59'), ('838:59:59'); Run the following code #include <sql.h> #include <sqlext.h> #include <stdio.h> #define CONNECTION_STRING "..." #define CONNECTION_STRING_LEN sizeof(CONNECTION_STRING) #define BUFF_SIZE 256 int main() { SQLHENV h_env = NULL; SQLHDBC h_dbc = NULL; SQLHSTMT h_stmt = NULL; SQLLEN i_text_len = 0; SQLSMALLINT i_out_connection_string_len = 0; char psz_txt_buff[BUFF_SIZE]; int ret = 0; SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &h_env); SQLSetEnvAttr( h_env, SQL_ATTR_ODBC_VERSION, (void *) SQL_OV_ODBC3, 0 ); SQLAllocHandle(SQL_HANDLE_DBC, h_env, &h_dbc); SQLDriverConnect(h_dbc, NULL, CONNECTION_STRING, CONNECTION_STRING_LEN, NULL, 0, &i_out_connection_string_len, SQL_DRIVER_NOPROMPT); SQLAllocHandle(SQL_HANDLE_STMT, h_dbc, &h_stmt); SQLPrepare(h_stmt, "SELECT typetime FROM time_tab;", SQL_NTS); SQLBindCol(h_stmt, 1, SQL_C_CHAR, &psz_txt_buff, sizeof(psz_txt_buff), &i_text_len); SQLExecute(h_stmt); do { ret = SQLFetch(h_stmt); if (ret == SQL_SUCCESS || ret == SQL_SUCCESS_WITH_INFO) printf("text='%s' len=%ld\n", psz_txt_buff, i_text_len); } while (ret == SQL_SUCCESS); } If the connection is in SSPS disabled mode (NO_SSPS=1; in connection string), then this code prints as expected: text='-838:59:59' len=10 text='838:59:59' len=9 When SSPS is enabled then the last characters are lost: text='-838:59:5' len=9 text='838:59:5' len=8 Suggested fix: The program should print same output regardless of if SSPS is enabled or not. I think the issue is with the source code of mysql-connector-odbc, in file driver/my_prepared_stmt.cc, function fetch_varlength_columns. The following code doesn't take into account that hour value for mysql can have 3 digits. case MYSQL_TYPE_TIME: { MYSQL_TIME * t = (MYSQL_TIME *)(col_rbind->buffer); buffer= ALLOC_IFNULL(buffer, 20); myodbc_snprintf(buffer, 10, "%s%02u:%02u:%02u", t->neg? "-":"", t->hour, t->minute, t->second); *length= t->neg ? 9 : 8; if (t->second_part > 0) { myodbc_snprintf(buffer+*length, 8, ".%06lu", t->second_part); *length+= 7; } return buffer; } The length and buffers are too small if t->hour >= 100.