问题就在于我们所插入的数据项中包含SQL关键字DROP TABLE,这两个关键字的意义是从数据库中清除一个表单。 而关键字之前的Robert');使得SQL执行器认为上一命令已经结束,从而使得危险指令DROP TABLE得到执行。 也就是说,这段包含DROP TABLE关键字的数据项使得原有的简单的插入姓名信息的SQL语句: 代码语言:javascript ...
#接着我们执行表结构的更新。 MySQL> alter table t1 add i int; Query OK, 0 rows affected (0.41 sec) Records: 0 Duplicates: 0 Warnings: 0#然后再次执行sp,就会发现这次执行了这句SQL的prepare再进行execute。 MySQL> call p1; Query OK, 0 rows affected (34.24 sec)...
解释 obclient> CREATE TABLE t4(c1 INT PRIMARY KEY, c2 INT); Query OK, 0 rows affected ob> INSERT t4 VALUES(10,10),(20,20),(30,30),(4040); Query OK, 4 rows affected Records: 4 Duplicates: 0 Warnings: 0 obclient> SELECT * FROM t4; +---+---+ | c1 | c2 | +---+-...
If multiple indexes are used in a single hint list, the duplicates are ignored, and the rest of the listed indexes are used to retrieve the rows of the table. The order of the indexes in the index hint is significant. A multiple index hint also enforces index ANDing, and the query opt...
I'm guessing my duplicates are coming from the second join where I alias order_proc as order_proc2. I am dealing with millions of rows and joining to several other tables as well to pull different types of information for the Persons and orders. I need to check a huge ...
You must also have space quota in the tablespace in which space is to be acquired in order to use the add_table_partition, modify_table_partition, move_table_partition, and split_table_partition clauses. Additional Prerequisites for Constraints and Triggers...
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DELETEFROMyour_tableWHERErowidnotin(SELECTMIN(rowid)FROMyour_tableGROUPBYcolumn1,column2,column3); The columns in theGROUP BY statementare those that are checked for duplicates. In the example I’ve been using, this is the first_name, last_name, and created_date. ...
例如,因为有一个COUNT() 函数,在下面的语句中使用COUNT作为表名会导致错误: mysql>CREATETABLEcount(iINT); ERROR1064(42000): You have an errorinyour SQL syntax 表名应加引号: mysql>CREATETABLE`count` (iINT); Query OK,0rows affected (0.00sec) IGNORE_SPACE SQL模式适用于内置函数,而不适用于可...
the two tables must not be delete-connected to each other where the delete rule of the last relationship in each path is RESTRICT or SET NULL. The delete rule specified in a FOREIGN KEY clause of the CREATE TABLE or ALTER TABLE statement is not valid for the reason specified by thereason...