mysql case/when语句在过程中答案

【问题标题】：mysql case/when statement within proceduremysql case/when语句在过程中
【发布时间】：2013-01-07 12:11:45
【问题描述】：

在第一个“;”之后我不断收到 1064 语法错误在第一个 when 语句中。我尝试了来自here 和here 的提示，但无济于事。帮助任何人？

DELIMITER //

CREATE PROCEDURE `test` ()
BEGIN
    SELECT *,
        case 
        when variable_1 between 0.75 and 4     then 4;
        when variable_1 between 0    and 0.74  then "<4";
        when variable_1 between 4.1  and 365  then ">4";
        end case as variable_2;
END //

答案后的修正问题：

实际代码：

DELIMITER //

CREATE PROCEDURE `infant_outcomes`.`new_procedure` ()
BEGIN
SELECT * FROM CDI

        INNER JOIN


    -- CDI subquery grouping and filtering 
    (SELECT CDI.subj_CDI as subj_CDI_grouping, Min(hearing_age_CDI) min_hearing_age_CDI,
    case 
    when CDI.hearing_age_CDI between 1.75 and 4.25 then 3
    when CDI.hearing_age_CDI between 4.75 and 7.25 then 6

    end as hearing_age_CDI_group
    FROM CDI
    group by CDI.subj_CDI, hearing_age_CDI_group
    ORDER BY CDI.subj_CDI, CDI.hearing_age_CDI ASC) CDI_filtered

        on
            CDI.subj_CDI = subj_CDI_grouping
            AND CDI.hearing_age_CDI = CDI_filtered.min_hearing_age_CDI

    where hearing_age_CDI_group is not null
    ORDER BY 
    CDI.subj_CDI, CDI_filtered.hearing_age_CDI_group
END //

我在“End //”处遇到语法错误虽然以下两个答案的组合有效，但实际代码本身会引发该错误...

【问题讨论】：

标签： mysql mysql-workbench

【解决方案1】：

因为你打破了陈述。

SELECT *,
    case 
    when variable_1 between 0.75 and 4     then "4"
    when variable_1 between 0    and 0.74  then "<4"
    when variable_1 between 4.1  and 365  then ">4"
    end as variable_2;

你错过了分号

ORDER BY 
CDI.subj_CDI, CDI_filtered.hearing_age_CDI_group;
                                                ^________ this.

【讨论】：

谢谢--示例代码有效，上面粘贴的“实际”代码不...想法？
@user996544 我在回答中告诉过，您在每个when 条件之后都有;，但整个CASE 都在声明中（从CASE 到END）。同样是第一次当/然后你错过了报价。

【解决方案2】：

case 表达式以“end”结尾，而不是“end case”。

删除尾随的“大小写”：

DELIMITER //

CREATE PROCEDURE `test` ()
BEGIN
    SELECT *,
        case 
        when variable_1 between 0.75 and 4     then 4;
        when variable_1 between 0    and 0.74  then "<4";
        when variable_1 between 4.1  and 365  then ">4";
        end as variable_2; -- "case" removed
END //

【讨论】：