From 84173f5ef8793d9400e6d7762efb86a688748d2c Mon Sep 17 00:00:00 2001 From: mxcgt <16550341+mxcgt@user.noreply.gitee.com> Date: Tue, 6 Jan 2026 02:38:23 +0000 Subject: [PATCH] =?UTF-8?q?update=2012-dev-guide/12-2-3-dp-table.md.=201?= =?UTF-8?q?=E3=80=81=E8=AF=AD=E6=B3=95=E8=A1=A8=E8=BF=B0=E4=B8=8D=E4=B8=A5?= =?UTF-8?q?=E8=B0=A8=EF=BC=88=E5=AD=97=E6=AE=B5=E5=91=BD=E5=90=8D=E4=B8=8D?= =?UTF-8?q?=E4=B8=80=E8=87=B4=EF=BC=89=09=E5=BB=BA=E8=A1=A8=E7=A4=BA?= =?UTF-8?q?=E4=BE=8B=E4=B8=AD=E5=88=97=E5=90=8D=E7=94=A8ename=EF=BC=88?= =?UTF-8?q?=E8=8B=B1=E6=96=87=E5=A7=93=E5=90=8D=EF=BC=89=EF=BC=8C=E4=BD=86?= =?UTF-8?q?=E5=AD=97=E6=AE=B5=E8=AF=B4=E6=98=8E=E5=86=99=20=E2=80=9Cname(?= =?UTF-8?q?=E5=A7=93=E5=90=8D)=E2=80=9D=EF=BC=8C=E4=BA=8C=E8=80=85?= =?UTF-8?q?=E4=B8=8D=E7=BB=9F=E4=B8=80=202=E3=80=81=E8=A7=84=E8=8C=83?= =?UTF-8?q?=E5=BC=95=E7=94=A8=E4=B8=8D=E8=90=BD=E5=9C=B0=EF=BC=88=E6=9C=AA?= =?UTF-8?q?=E5=90=8C=E6=AD=A5=E5=BF=85=E5=A4=87=E5=AD=97=E6=AE=B5=E8=A6=81?= =?UTF-8?q?=E6=B1=82=EF=BC=89=09=E5=BC=95=E7=94=A8=E3=80=8AJava=20?= =?UTF-8?q?=E5=BC=80=E5=8F=91=E6=89=8B=E5=86=8C=E3=80=8B=E2=80=9C=E8=A1=A8?= =?UTF-8?q?=E5=BF=85=E5=A4=87=E4=B8=89=E5=AD=97=E6=AE=B5=EF=BC=9Aid,=20gmt?= =?UTF-8?q?=5Fcreate,=20gmt=5Fmodified=E2=80=9D=EF=BC=8C=E4=BD=86=E5=BB=BA?= =?UTF-8?q?=E8=A1=A8=E7=A4=BA=E4=BE=8B=E6=9C=AA=E5=8C=85=E5=90=ABgmt=5Fcre?= =?UTF-8?q?ate=E5=92=8Cgmt=5Fmodified=E5=AD=97=E6=AE=B5=203=E3=80=81?= =?UTF-8?q?=E6=B8=85=E7=A9=BA=E8=A1=A8=E6=93=8D=E4=BD=9C=E8=AF=B4=E6=98=8E?= =?UTF-8?q?=E7=BC=BA=E5=A4=B1=E9=A3=8E=E9=99=A9=E6=8F=90=E7=A4=BA=09?= =?UTF-8?q?=E4=BB=85=E8=AF=B4=E6=98=8ETRUNCATE=20TABLE=E2=80=9C=E4=B8=8D?= =?UTF-8?q?=E5=88=A0=E9=99=A4=E8=A1=A8=E7=BB=93=E6=9E=84=EF=BC=8C=E5=8F=AA?= =?UTF-8?q?=E5=88=A0=E9=99=A4=E5=86=85=E5=AE=B9=E2=80=9D=EF=BC=8C=E6=9C=AA?= =?UTF-8?q?=E6=8F=90=E7=A4=BA=E5=85=B6=E4=B8=8EDELETE=E7=9A=84=E5=B7=AE?= =?UTF-8?q?=E5=BC=82=E5=8F=8A=E4=BD=BF=E7=94=A8=E9=99=90=E5=88=B6?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: mxcgt <16550341+mxcgt@user.noreply.gitee.com> --- 12-dev-guide/12-2-3-dp-table.md | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/12-dev-guide/12-2-3-dp-table.md b/12-dev-guide/12-2-3-dp-table.md index a08addc..6eba3ca 100644 --- a/12-dev-guide/12-2-3-dp-table.md +++ b/12-dev-guide/12-2-3-dp-table.md @@ -28,9 +28,11 @@ CREATE TABLE [IF NOT EXISTS] tablename( ```sql CREATE TABLE test_greatsql( id INT NOT NULL AUTO_INCREMENT, - ename VARCHAR(10) NOT NULL, + name VARCHAR(10) NOT NULL, gender CHAR(1) NOT NULL, address VARCHAR(20) NOT NULL, + gmt_create DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间', + gmt_modified DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间', PRIMARY KEY(id) ); ``` @@ -42,9 +44,11 @@ greatsql> SHOW CREATE TABLE test_greatsql \G Table: test_greatsql Create Table: CREATE TABLE `test_greatsql` ( `id` int NOT NULL AUTO_INCREMENT, - `ename` varchar(10) NOT NULL, + `name` varchar(10) NOT NULL, `gender` char(1) NOT NULL, `address` varchar(20) NOT NULL, + `gmt_create` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间', + `gmt_modified` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间', PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci 1 row in set (0.00 sec) @@ -61,6 +65,10 @@ DROP TABLE test_greatsql; ``` ### 清空表 不删除表结构，只删除内容 +补充风险提示： +1. TRUNCATE会重置自增主键（AUTO_INCREMENT回归初始值），DELETE不会； +2. 无法撤销，若表数据需保留备份，需提前导出； +3. 若表存在外键关联，需先禁用外键约束才能执行，否则报错 ```sql TRUNCATE TABLE tablename; ``` -- Gitee