使用phpMyAdmin SQL查询的日期显示格式答案

【问题标题】：Date display format using phpMyAdmin SQL query使用phpMyAdmin SQL查询的日期显示格式
【发布时间】：2020-01-13 17:46:48
【问题描述】：

当我在 phpMyAdmin 中运行我的 SQL 时，我的日期时间字段 (pm_expense_ledger.hos_date) 以这种格式显示：2019-10-01 00:00:00

虽然这不是最终用户 GUI，但我如何格式化日期时间字段以仅显示为 DDMMMYYYY ("%d %b %Y")，因为我在运行查询时不需要尖齿？

你可以看到我尝试了几次都不成功！

代码：

    SELECT pm_expense_ledger_el_connector.property_id AS PropId,
    /*    show FIELDS from pm_expense_ledger; to view field column types */
        pm_expense_ledger.hos_date AS Date, /* this is a datetime field */
    /*    DATE_FORMAT('pm_expense_ledger.hos_date', '%d%b%Y') AS FDate,    returns null values */
    /*    DATE_FORMAT("pm_expense_ledger.hos_date", "%d %b %Y %H-%i-%S") AS D1,*/
    /*    DATE('pm_expense_ledger.hos_date', '%d %b %Y') AS D2,*/
    /*    DATE("pm_expense_ledger.hos_date", "%d %b %Y") AS D3, no difference using single or double quotes */
    /*    DATA_TYPE('pm_expense_ledger.hos_date'),*/
        pm_homeowner_statement_key.key_name AS Item,
        pm_expense_ledger_description.descr AS Description,
        pm_expense_ledger_el_connector.hos_total AS HOS,
        pm_expense_ledger.pm_expense_ledger_id AS pmelid,
        pm_expense_ledger.expense_ledger_id AS elid
    FROM  pm_expense_ledger_el_connector
    JOIN pm_expense_ledger
        on pm_expense_ledger.pm_expense_ledger_id = pm_expense_ledger_el_connector.pm_exp_ledger_id
    JOIN pm_expense_ledger_description
        on pm_expense_ledger_description.pm_el_description_id = pm_expense_ledger.pm_exp_ledg_descr_id
    JOIN pm_homeowner_statement_key
        on pm_homeowner_statement_key.pm_hos_key_id = pm_expense_ledger.pm_hos_key_id

    where pm_expense_ledger.hos_date BETWEEN '2019,12,01' and '2019,12,31'
    /*group by pm_expense_ledger_el_connector.property_id*/
    order by pm_expense_ledger_el_connector.property_id ASC, pm_expense_ledger.hos_date ASC, pm_expense_ledger_id ASC;

【问题讨论】：

让数据库返回原始二进制日期时间值并让客户端应用程序担心格式通常会更有效。

标签： mysql sql date datetime

【解决方案1】：

你想要：

DATE_FORMAT(pm_expense_ledger.hos_date, '%d%b%Y') AS FDate

以下尝试已接近：

DATE_FORMAT('pm_expense_ledger.hos_date', '%d%b%Y')

由于列名周围的单引号导致它成为字符串而失败；由于该字符串无法转换为datetime，因此date_format() 会生成null 值。

底线：在 MySQL 中，不要在标识符周围使用引号（单引号或双引号）；如果出于某种原因需要引用标识符（因为它包含特殊字符），则需要使用反引号 (`)。

【讨论】：