SELECT VERSION()查看数据库当前版本 0.2 MYSQL ERROR CODE 错误编号(合集) 0.3 SQLSTATE[HY000]:执行查询后出现常规错误 SQLSTATE[HY000]是一种SQL语句执行错误的状态码,表示在执行查询时发生了常规错误。 该错误码是由SQL标准定义的,不仅适用于特定的数据库系统,也适用于各种关系型数据库。 常规错误可能包括以下几...
If the value is func, the value used is the result of some function. To see which function, use SHOW WARNINGS following EXPLAIN to see the extended EXPLAIN output. The function might actually be an operator such as an arithmetic operator. • rows (JSON name: rows) The rows column indica...
For the INTO var_list variant: var_list names a list of one or more variables, each of which can be a user-defined variable, stored procedure or function parameter, or stored program local variable. (Within a prepared SELECT ... INTO var_list statement, only user-defined variables are pe...
mysql> insert into test_table(id,password) values('3','test3'); Query OK, 1 row affected (0.03 sec) mysql> select * from test_table; +---+---+ | id | password | +---+---+ | 1 | test1 | | 2 | test2 | | 3 | test3 | +---+---+ 3 rows in set (0.02 sec) 1...
Please make sure that the page_size is already set when invoking the function, so that we can get correct page_size from the buffer page when adding a block into LRU */ void buf_LRU_add_block(buf_page_t *bpage, /*!< in: control block */ ibool old) /*!< in: TRUE if should...
SELECTGTID_INTERSECTION_WITH_UUID(@@GLOBAL.gtid_executed,my_server_uuid); Example 16.6 Validating an additional replica in multisource replication The stored functionGTID_INTERSECTION_WITH_UUID()can be used to find out if a replica attached to a multisource replication setup has applied all the tr...
A multiple-column index can be considered a sorted array, the rows of which contain values that are created by concatenating the values of the indexed columns. 联合索引是多列按照次序一列一列比较大小,拿idx_book_id_hero_name这个联合索引来说,先比较book_id,book_id小的排在左边,book_id大的排在...
query('SELECT * FROM users WHERE id = ?', [userId], function (error, results, fields) { if (error) throw error; // ... }); Multiple placeholders are mapped to values in the same order as passed. For example, in the following query foo equals a, bar equals b, baz equals c, ...
SHOW CREATE EVENT event_name SHOW CREATE FUNCTION funcname。。。 我想知道create table的语法,可以命令如下: mysql> ? create tableName: 'CREATE TABLE' Description: Syntax: CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name (create_definition,...) [table_...
The length of rows depends on the SELECT list columns and the invisible columns that are present in other places, like GROUP BY or ORDER BY. If you have specified a smaller sort buffer size, then algorithm will never function. Hence, everything is fixed, but you do have some tuning to ...