错误消息 156，级别 15，状态 1，关键字 'CONTINUE' 附近的语法不正确

Question

我需要一些帮助来制作这个 MySQL 游标，我一直在遵循这个指南：http://www.mysqltutorial.org/mysql-cursor/。我正在尝试使游标遍历 table 并一次创建一行名称列表。

CREATE PROCEDURE build_people_table ( @people varchar(4000))
AS
BEGIN
DECLARE @v_finished INT;
    DECLARE @v_name nvarchar(255);


    --Main Cursor
    DECLARE people_cursor CURSOR FOR
    SELECT [Person Name]
    FROM [dbo].[People];

     -- declare NOT FOUND handler
 DECLARE CONTINUE HANDLER 
        FOR NOT FOUND SET @v_finished = 1;


    OPEN people_cursor;

    get_name: LOOP

    FETCH people_cursor INTO @v_name ;

    IF @v_finished = 1 THEN
    LEAVE get_name;
    END IF;

    SET @people = CONCAT(@v_name,';',@people);
    END LOOP get_name;

    CLOSE people_cursor;

END

mySQL 错误信息

Msg 156, Level 15, State 1, Procedure build_people_table, Line 41
Incorrect syntax near the keyword 'CONTINUE'.
Msg 136, Level 15, State 1, Procedure build_people_table, Line 41
Cannot use a CONTINUE statement outside the scope of a WHILE statement.
Msg 102, Level 15, State 1, Procedure build_people_table, Line 47
Incorrect syntax near 'LOOP'.
Msg 156, Level 15, State 1, Procedure build_people_table, Line 56
Incorrect syntax near the keyword 'THEN'.
Msg 102, Level 15, State 1, Procedure build_people_table, Line 61
Incorrect syntax near 'LOOP'.
Msg 156, Level 15, State 1, Procedure build_people_table, Line 74
Incorrect syntax near the keyword 'END'.

Answer 1

这表明它以 Mysql 结尾到结尾（您所说的您正在使用的技术）。

注意，最好用

select group_concat(`Person Name`) from People;

为此。但不管出于什么原因，你似乎想为它写一个存储过程，也许是出于学习目的。重要的是要注意游标就像 非常慢。

另请注意，您的输出缓冲区（out 参数）很有可能溢出。有很多数据可以进入那里。所以我将它从 varchar(4000) 更改为 TEXT。

架构

create table People
(   id int auto_increment primary key,
    `Person Name` varchar(200)
); 

insert People(`Person Name`) values ('John Henry'),('Kim Billings'),('Gertrude Smith');

存储过程

drop procedure if exists build_people_table;
DELIMITER $$
CREATE PROCEDURE build_people_table ( OUT people_out TEXT)
BEGIN
    DECLARE done INT DEFAULT FALSE;
    DECLARE v_name nvarchar(255);
    -- DECLARE bFirst boolean DEFAULT TRUE;


    -- Main Cursor
    DECLARE people_cursor CURSOR FOR
    SELECT `Person Name`
    FROM `People`;

    -- declare NOT FOUND handler
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done=TRUE;


    OPEN people_cursor;
    set @people='';

    get_name: LOOP

        FETCH people_cursor INTO v_name;

        IF done THEN
            LEAVE get_name;
        END IF;
        SET @people:= CONCAT(v_name,";",@people);
        -- SET @people:= CONCAT(@people,";",v_name);
    END LOOP get_name;

    CLOSE people_cursor;
    set people_out:=@people;
    -- select @people; -- used for debugging
END
$$
DELIMITER ;

测试

set @saveHere:='';
call build_people_table(@saveHere);
select @saveHere; -- show results

'Gertrude Smith;Kim Billings;John Henry;'

错误消息 156，级别 15，状态 1，关键字 'CONTINUE' 附近的语法不正确

ERROR Msg 156, Level 15, State 1, Incorrect syntax near the keyword 'CONTINUE'

mysql

triggers

stored-procedures

cursor

架构

存储过程

测试