From 76d498b9a3ab5b95ef1ac7a9e7c208d7000d9d85 Mon Sep 17 00:00:00 2001
From: Doghole <huocaizhu@gmail.com>
Date: Sun, 16 Nov 2025 23:17:03 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=E9=BB=98=E8=AE=A4=E9=85=8D?=
 =?UTF-8?q?=E7=BD=AE=E8=A7=A6=E5=8F=91=E5=99=A8=E7=9B=B8=E5=85=B3=E7=9A=84?=
 =?UTF-8?q?=E6=96=87=E6=A1=A3?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/resources/database.db                | Bin 49152 -> 49152 bytes
 ...fault-true-in-sqlite3-datatable-trigger.md | 101 ++++++++++++++++++
 ...fault-true-in-sqlite3-datatable-trigger.md |   2 -
 3 files changed, 101 insertions(+), 2 deletions(-)
 create mode 100644 src/main/resources/docs/only-one-default-true-in-sqlite3-datatable-trigger.md
 delete mode 100644 src/main/resources/only-one-default-true-in-sqlite3-datatable-trigger.md

diff --git a/src/main/resources/database.db b/src/main/resources/database.db
index 4779ce043e52d25a42b0e8c08086c0e394216db2..4f266790be0073fbc054c8d93aab31b5f5bfdb49 100644
GIT binary patch
delta 578
zcmZo@U~Xt&o**rFlYxPO2a1`1^qGk|#*8;NCM=O>X5xRmnO)&FKO^Vn$NF*#vdohi
zxS1jt_<r%O;7R9B;Ns(W%RZN_hP9e0g2jI0L{>(w=9DCM=}>i!w(!XfQKFLzBG>6D
zC^)&gd-^E^yZX2~hbV9<K!LMkuq%QG5)Ain^_%R#Dn2<cOqr|6A_Z(xb3M$Y$<k4>
z>`?8K8H0r#A#9+oAXkOV6a^bQ1wYqtz04Gt6^?!`3Yo?6DXD3Rr8y-EwhD&U3a)-G
zKtHYlyD<`MvTYFO<V_)(lly}?CYuNGPj(D<;cBu>1zX<2h(k#lx?{}Abj;?dQA~_X
za`BTDgX9+fiDle;E`Wz^Q$!Hs=IPO_jGGep9N74+L2$F8f;xY_947~Zw5U82Cx@G-
zi;ItIkVi;JKu&&gVopYWaf#9npx+z_$SdHJmt%&S&*_$#l9H2JglhieUF$U&IVRuP
JFSBTa005~Jngjp<

delta 341
zcmZo@U~Xt&o**rFhJk^B2a1`1^nr;w#*Ak+CM=O>X6C=JnO)&FKO^(z$NF*#vRq{h
z+zjU!xTkRjvj1nh$vT5&BC|b{9K$)@+gwv8PTa70Za5Dcr*b5_bf`K<bLix`!HXuJ
z4^*1GJ(72_Y$)$!!%*SL_MF<ASHuQ0aw>&Glm$=L4Lm$qAXEw_EzdKDL0&pom803W
zq$o2zJ+&w$H7&6;rzGAmJ~6E%b#rwn6XWLJajcA7e1912r2~N~y(fFKOHW?U!8f^q
z!*25XurQ#V;VKLaj84*_svIr+P=kt63rkarOX4&0((>bzGg6!6;wOKIkXt-AjFAPX
zm}T)XR>n;Ud=8rx6^i&()tNaNq($YKI62wfGE-7=Qj0u7LIQH~lM{2~m^mO)9Fv!>
Pw`1g-d}qJRq74E7M&f3p

diff --git a/src/main/resources/docs/only-one-default-true-in-sqlite3-datatable-trigger.md b/src/main/resources/docs/only-one-default-true-in-sqlite3-datatable-trigger.md
new file mode 100644
index 0000000..e05b90e
--- /dev/null
+++ b/src/main/resources/docs/only-one-default-true-in-sqlite3-datatable-trigger.md
@@ -0,0 +1,101 @@
+## 使用触发器在 SQLite3 数据表内实现唯一的默认配置
+
+系统设计了 `RequestInfo` 和 `ProxySetting` 两个实体类来配置请求信息和代理设置，对应到 SQLite 表中分别是 `request_info` 和 `proxy_setting`，两者都有 `is_default` 字段。
+
+由于同一时间内，数据表中只能存在一条 `is_default` 为 1 的记录，所以要进行一些设置。按照传统方法，需要在 Java 代码中，任何对数据记录 CRUD 的地方进行限制，但由于需要覆写的方法太多，又容易有纰漏，所以直接在数据表内用触发器限制。
+
+以 `proxy_setting` 表为例，我们需要 5 个触发器来实现这个功能。
+
+### AFTER INSERT is_default = 1 时的触发器
+
+```sqlite
+CREATE TRIGGER default_1_after_insert_proxy_setting
+         AFTER INSERT
+            ON proxy_setting
+      FOR EACH ROW
+          WHEN CAST (NEW.is_default AS INTEGER) = 1
+BEGIN
+    UPDATE proxy_setting
+       SET is_default = 0
+     WHERE is_default = 1 AND
+           id <> NEW.id;
+END;
+```
+
+在 INSERT 之后，对每一行，如果 is_default = 1 的，如果旧记录有 is_default = 1 的，将旧记录 is_default 置为 0.
+
+### AFTER UPDATE is_default = 1 时的触发器
+
+```sqlite
+CREATE TRIGGER default_1_after_update_proxy_setting
+         AFTER UPDATE
+            ON proxy_setting
+      FOR EACH ROW
+          WHEN CAST (NEW.is_default AS INTEGER) = 1
+BEGIN
+    UPDATE proxy_setting
+       SET is_default = 0
+     WHERE id <> NEW.id AND
+           is_default = 1;
+END;
+```
+
+和 INSERT 类似，但是 UPDATE 场景。
+
+### BEFORE INSERT is_default = 0 时的触发器
+
+```sqlite
+CREATE TRIGGER default_0_before_insert_proxy_setting
+        BEFORE INSERT
+            ON proxy_setting
+      FOR EACH ROW
+          WHEN NEW.is_default = 0 AND
+               (
+                   SELECT COUNT( * ) 
+                     FROM proxy_setting
+                    WHERE is_default = 1
+               )
+=              0
+BEGIN
+    SELECT RAISE(ABORT, "需要配置一条默认代理");
+END;
+```
+
+在插入之前，如果本条为 0 且数据表内不包含默认配置（即 is_default = 1的记录）的，不允许插入。
+
+### BEFORE UPDATE is_default = 0 时的触发器
+
+```sqlite
+CREATE TRIGGER default_0_before_update_proxy_setting
+        BEFORE UPDATE
+            ON proxy_setting
+      FOR EACH ROW
+          WHEN NEW.is_default = 0 AND
+               (
+                   SELECT COUNT( * ) 
+                     FROM proxy_setting
+                    WHERE is_default = 1 AND
+                          id <> NEW.id
+               )
+=              0
+BEGIN
+    SELECT RAISE(ABORT, "需要配置一条默认代理");
+END;
+```
+
+和 INSERT 场景类似。
+
+### BEFORE DELETE 触发器
+
+```sqlite
+CREATE TRIGGER protect_default_proxy_setting
+        BEFORE DELETE
+            ON proxy_setting
+      FOR EACH ROW
+          WHEN OLD.is_default = 1
+BEGIN
+    SELECT RAISE(ABORT, "待删除数据中有默认代理，不允许删除！");
+END;
+```
+
+如果待删除的记录中包含默认配置，则不允许删除。
\ No newline at end of file
diff --git a/src/main/resources/only-one-default-true-in-sqlite3-datatable-trigger.md b/src/main/resources/only-one-default-true-in-sqlite3-datatable-trigger.md
deleted file mode 100644
index 87ff934..0000000
--- a/src/main/resources/only-one-default-true-in-sqlite3-datatable-trigger.md
+++ /dev/null
@@ -1,2 +0,0 @@
-## 使用触发器在 SQLite3 数据表内实现唯一的默认配置
-