[td-14493] add a new api.

include/client/taos.h

@@ -152,34 +152,34 @@ DLL_EXPORT void  taos_close(TAOS *taos);
 
 const char *taos_data_type(int type);
 
-DLL_EXPORT TAOS_STMT *taos_stmt_init(TAOS *taos);
-DLL_EXPORT int        taos_stmt_prepare(TAOS_STMT *stmt, const char *sql, unsigned long length);
-DLL_EXPORT int        taos_stmt_set_tbname_tags(TAOS_STMT *stmt, const char *name, TAOS_BIND *tags);
-DLL_EXPORT int        taos_stmt_set_tbname(TAOS_STMT *stmt, const char *name);
-DLL_EXPORT int        taos_stmt_set_sub_tbname(TAOS_STMT *stmt, const char *name);
-
-DLL_EXPORT int       taos_stmt_is_insert(TAOS_STMT *stmt, int *insert);
-DLL_EXPORT int       taos_stmt_num_params(TAOS_STMT *stmt, int *nums);
-DLL_EXPORT int       taos_stmt_get_param(TAOS_STMT *stmt, int idx, int *type, int *bytes);
-DLL_EXPORT int       taos_stmt_bind_param(TAOS_STMT *stmt, TAOS_BIND *bind);
-DLL_EXPORT int       taos_stmt_bind_param_batch(TAOS_STMT *stmt, TAOS_MULTI_BIND *bind);
-DLL_EXPORT int       taos_stmt_bind_single_param_batch(TAOS_STMT *stmt, TAOS_MULTI_BIND *bind, int colIdx);
-DLL_EXPORT int       taos_stmt_add_batch(TAOS_STMT *stmt);
-DLL_EXPORT int       taos_stmt_execute(TAOS_STMT *stmt);
-DLL_EXPORT TAOS_RES *taos_stmt_use_result(TAOS_STMT *stmt);
-DLL_EXPORT int       taos_stmt_close(TAOS_STMT *stmt);
-DLL_EXPORT char     *taos_stmt_errstr(TAOS_STMT *stmt);
-DLL_EXPORT int       taos_stmt_affected_rows(TAOS_STMT *stmt);
-
-DLL_EXPORT TAOS_RES *taos_query(TAOS *taos, const char *sql);
-DLL_EXPORT TAOS_RES *taos_query_l(TAOS *taos, const char *sql, int sqlLen);
-
-DLL_EXPORT TAOS_ROW taos_fetch_row(TAOS_RES *res);
-DLL_EXPORT int      taos_result_precision(TAOS_RES *res);  // get the time precision of result
-DLL_EXPORT void     taos_free_result(TAOS_RES *res);
-DLL_EXPORT int      taos_field_count(TAOS_RES *res);
-DLL_EXPORT int      taos_num_fields(TAOS_RES *res);
-DLL_EXPORT int      taos_affected_rows(TAOS_RES *res);
+DLL_EXPORT TAOS_STMT  *taos_stmt_init(TAOS *taos);
+DLL_EXPORT int         taos_stmt_prepare(TAOS_STMT *stmt, const char *sql, unsigned long length);
+DLL_EXPORT int         taos_stmt_set_tbname_tags(TAOS_STMT *stmt, const char *name, TAOS_BIND *tags);
+DLL_EXPORT int         taos_stmt_set_tbname(TAOS_STMT *stmt, const char *name);
+DLL_EXPORT int         taos_stmt_set_sub_tbname(TAOS_STMT *stmt, const char *name);
+
+DLL_EXPORT int         taos_stmt_is_insert(TAOS_STMT *stmt, int *insert);
+DLL_EXPORT int         taos_stmt_num_params(TAOS_STMT *stmt, int *nums);
+DLL_EXPORT int         taos_stmt_get_param(TAOS_STMT *stmt, int idx, int *type, int *bytes);
+DLL_EXPORT int         taos_stmt_bind_param(TAOS_STMT *stmt, TAOS_BIND *bind);
+DLL_EXPORT int         taos_stmt_bind_param_batch(TAOS_STMT *stmt, TAOS_MULTI_BIND *bind);
+DLL_EXPORT int         taos_stmt_bind_single_param_batch(TAOS_STMT *stmt, TAOS_MULTI_BIND *bind, int colIdx);
+DLL_EXPORT int         taos_stmt_add_batch(TAOS_STMT *stmt);
+DLL_EXPORT int         taos_stmt_execute(TAOS_STMT *stmt);
+DLL_EXPORT TAOS_RES   *taos_stmt_use_result(TAOS_STMT *stmt);
+DLL_EXPORT int         taos_stmt_close(TAOS_STMT *stmt);
+DLL_EXPORT char       *taos_stmt_errstr(TAOS_STMT *stmt);
+DLL_EXPORT int         taos_stmt_affected_rows(TAOS_STMT *stmt);
+
+DLL_EXPORT TAOS_RES   *taos_query(TAOS *taos, const char *sql);
+DLL_EXPORT TAOS_RES   *taos_query_l(TAOS *taos, const char *sql, int sqlLen);
+
+DLL_EXPORT TAOS_ROW    taos_fetch_row(TAOS_RES *res);
+DLL_EXPORT int         taos_result_precision(TAOS_RES *res);  // get the time precision of result
+DLL_EXPORT void        taos_free_result(TAOS_RES *res);
+DLL_EXPORT int         taos_field_count(TAOS_RES *res);
+DLL_EXPORT int         taos_num_fields(TAOS_RES *res);
+DLL_EXPORT int         taos_affected_rows(TAOS_RES *res);
 
 DLL_EXPORT TAOS_FIELD *taos_fetch_fields(TAOS_RES *res);
 DLL_EXPORT int         taos_select_db(TAOS *taos, const char *db);
@@ -188,11 +188,12 @@ DLL_EXPORT void        taos_stop_query(TAOS_RES *res);
 DLL_EXPORT bool        taos_is_null(TAOS_RES *res, int32_t row, int32_t col);
 DLL_EXPORT bool        taos_is_update_query(TAOS_RES *res);
 DLL_EXPORT int         taos_fetch_block(TAOS_RES *res, TAOS_ROW *rows);
+DLL_EXPORT int        *taos_get_column_data_offset(TAOS_RES *res, int columnIndex);
 DLL_EXPORT int         taos_validate_sql(TAOS *taos, const char *sql);
 DLL_EXPORT void        taos_reset_current_db(TAOS *taos);
 
-DLL_EXPORT int *taos_fetch_lengths(TAOS_RES *res);
-DLL_EXPORT TAOS_ROW *taos_result_block(TAOS_RES *res);
+DLL_EXPORT int        *taos_fetch_lengths(TAOS_RES *res);
+DLL_EXPORT TAOS_ROW   *taos_result_block(TAOS_RES *res);
 
 DLL_EXPORT const char *taos_get_server_info(TAOS *taos);
 DLL_EXPORT const char *taos_get_client_info();

source/client/src/clientMain.c

@@ -385,11 +385,11 @@ bool taos_is_update_query(TAOS_RES *res) {
 }
 
 int taos_fetch_block(TAOS_RES *res, TAOS_ROW *rows) {
-  if (res == NULL) {
+  SRequestObj *pRequest = (SRequestObj *)res;
+  if (pRequest == NULL) {
     return 0;
   }
 
-  SRequestObj *pRequest = (SRequestObj *)res;
   if (pRequest->type == TSDB_SQL_RETRIEVE_EMPTY_RESULT || pRequest->type == TSDB_SQL_INSERT ||
       pRequest->code != TSDB_CODE_SUCCESS || taos_num_fields(res) == 0) {
     return 0;
@@ -405,6 +405,25 @@ int taos_fetch_block(TAOS_RES *res, TAOS_ROW *rows) {
   return pResultInfo->numOfRows;
 }
 
+int *taos_get_column_data_offset(TAOS_RES *res, int columnIndex) {
+  SRequestObj *pRequest = (SRequestObj *)res;
+  if (pRequest == NULL) {
+    return 0;
+  }
+
+  int32_t numOfFields = taos_num_fields(pRequest);
+  if (columnIndex < 0 || columnIndex >= numOfFields || numOfFields == 0) {
+    return 0;
+  }
+
+  TAOS_FIELD* pField = &pRequest->body.resInfo.userFields[columnIndex];
+  if (!IS_VAR_DATA_TYPE(pField->type)) {
+    return 0;
+  }
+
+  return pRequest->body.resInfo.pCol[columnIndex].offset;
+}
+
 int taos_validate_sql(TAOS *taos, const char *sql) { return true; }
 
 void taos_reset_current_db(TAOS *taos) {