In this post, you’ll learn how to delete a row in SQL and how to delete all rows in a table. Table of Contents Sample Data Delete a Row in SQL Delete Multiple Rows in SQL Delete All Rows Sample Data Let’s say we have a table called “product” that looks like this: id ...
如果SQL 在執行 DELETE 陳述式時發現錯誤,則會停止刪除資料並傳回負 SQLCODE。 如果您指定 COMMIT (*ALL)、COMMIT (*CS)、COMMIT (*CHG) 或 COMMIT (*RR) ,則不會刪除表格中的任何橫列 (此陳述式已刪除的橫列 (如果有的話) 會還原為先前的值)。 如果指定 COMMIT (*NONE) ,任何已刪除的橫列 不會 還...
the rows are deletedintheorderthatisspecified. The LIMIT clause places a limitonthenumberofrows that can be deleted. These clauses applytosingle-tabledeletes,
UPDATE pay_stream a SET a.return_amount = 0 WHERE a.pay_id IN (SELECT b.pay_id FROM pay_main b WHERE b.user_name = '1388888888'); id select_type table partitions type possible_keys key key_len ref rows filtered Extra --- --- --- --- --- --- --- --- --- --- ---...
我们发现union all 的所用的 type【type为显示连接使用了何种类型】 为ref 而or和in为range【ref连接类型优于range,相差不了多少】,而查询行数都一样【看rows字段都是为3】。 从整个的过程来看,在索引列使用常数or及in和union all查询相差不了多少。
SELECT...FROM <tab> UPTO<n> ROWS... WHERE语句: 1.where条件语句 SELECT...WHERE <opertor> <f> ... 2.常用语句 SELECT...WHERE [NOT]BETWEEN<f1>AND<F2>.SELECT...WHERE COL2LIKE'_ABC%'.SELECT...WHERE [NOT]IN(<f1>,..,<fn>)...SELECT...WHERE [NOT]IN<seltab>... 查询存...
It is possible to delete all rows in a table without deleting the table. This means that the table structure, attributes, and indexes will be intact: The following SQL statement deletes all rows in the "Customers" table, without deleting the table. This means that the table structure, attri...
The searched DELETE form is used to delete one or more rows, optionally determined by a search condition. The positioned DELETE form specifies that one or more rows corresponding to the current cursor position are to be deleted. Invocation This statement can be embedded in an application program...
开始我们拿sql到数据库查询平台查库执行计划,无奈这个平台有bug,delete语句无法查看,所以我们改成select,“应该”是一样。这个“应该”加了双引号,导致我们走了一点弯路。EXPLAIN SELECT * from t_table_1 where task_id in (select id from t_table_2 where uid = 1) explain后可以看到是走了索引的 到这里...
9 rows in set (0.00 sec) mysql> BEGIN; # 开启事务 Query OK, 0 rows affected (0.00 sec) mysql> INSERT INTO Transaction_table VALUE(5); # 往表中插入数据 Query OK, 1 row affected (0.00 sec) mysql> INSERT INTO Transaction_table VALUE(6); # 往表中插入数据 ...