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...
Now, we will assign a value to variable from a scalar-valued function: 现在,我们将为标量值函数的变量赋值: DECLARE @StockVal AS INT SELECT @StockVal=dbo.ufnGetStock(1) SELECT @StockVal AS [VariableVal] 1. 2. 3. (Multiple SQL Variables ) For different cases, we may need to declare m...
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 @param[in] bpage control block @param[in] old TRUE if should be put to the old blocks in the LRU list, else put t...
Before MySQL 5.0.10, stored functions created withCREATE FUNCTIONmust not contain references to tables, with limited exceptions. They may include someSETstatements that contain table references, for exampleSET a:= (SELECT MAX(id) FROM t), andSELECTstatements that fetch values directly into variables...
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...
var_listnames 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 preparedSELECT ... INTOvar_liststatement, only user-defined variables are permitted; seeSection 15.6.4.2, “Local ...
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_...
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...
SELECT SUBSTRING('{String Value}', {start_index}, {count}); // format 2 SELECT SUBSTRING('{String Value}'FROM {start_index} for {count}); There are 2 ways in which we can use the SUBSTRING function. Let’s understand the syntax before we dive into the examples. ...
Use RETURN instead of SET at function return point : BEGIN RETURN (SELECT A INTO FROM T WHERE ID = 22); -- say there is no such a row -- in this case return value is NULL END; 2. Use CONDITON HANDLER. Recommended and suitable for multiple variables : BEGIN DECLARE COL_A, COL_...