row0sel.ic
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:2k
- /******************************************************
- Select
- (c) 1997 Innobase Oy
- Created 12/19/1997 Heikki Tuuri
- *******************************************************/
- #include "que0que.h"
- /*************************************************************************
- Gets the plan node for the nth table in a join. */
- UNIV_INLINE
- plan_t*
- sel_node_get_nth_plan(
- /*==================*/
- /* out: plan node */
- sel_node_t* node, /* in: select node */
- ulint i) /* in: get ith plan node */
- {
- ut_ad(i < node->n_tables);
- return(node->plans + i);
- }
- /*************************************************************************
- Resets the cursor defined by sel_node to the SEL_NODE_OPEN state, which means
- that it will start fetching from the start of the result set again, regardless
- of where it was before, and it will set intention locks on the tables. */
- UNIV_INLINE
- void
- sel_node_reset_cursor(
- /*==================*/
- sel_node_t* node) /* in: select node */
- {
- node->state = SEL_NODE_OPEN;
- }
- /**************************************************************************
- Performs an execution step of an open or close cursor statement node. */
- UNIV_INLINE
- que_thr_t*
- open_step(
- /*======*/
- /* out: query thread to run next or NULL */
- que_thr_t* thr) /* in: query thread */
- {
- sel_node_t* sel_node;
- open_node_t* node;
- ulint err;
- ut_ad(thr);
-
- node = thr->run_node;
- ut_ad(que_node_get_type(node) == QUE_NODE_OPEN);
- sel_node = node->cursor_def;
- err = DB_SUCCESS;
- if (node->op_type == ROW_SEL_OPEN_CURSOR) {
- /* if (sel_node->state == SEL_NODE_CLOSED) { */
- sel_node_reset_cursor(sel_node);
- /* } else {
- err = DB_ERROR;
- } */
- } else {
- if (sel_node->state != SEL_NODE_CLOSED) {
- sel_node->state = SEL_NODE_CLOSED;
- } else {
- err = DB_ERROR;
- }
- }
-
- if (err != DB_SUCCESS) {
- /* SQL error detected */
- fprintf(stderr, "SQL error %lun", (ulong) err);
- ut_error;
- }
-
- thr->run_node = que_node_get_parent(node);
-
- return(thr);
- }