From 9d464caf3eea715deb8abb5af017ffdb40aba372 Mon Sep 17 00:00:00 2001
From: Suomm <1474983351@qq.com>
Date: Thu, 9 Nov 2023 21:12:24 +0800
Subject: [PATCH] =?UTF-8?q?feat:=20=E6=B7=BB=E5=8A=A0=E5=8F=96=E7=9B=B8?=
 =?UTF-8?q?=E5=8F=8D=E6=95=B0=E7=9A=84=E6=9E=84=E5=BB=BA=E3=80=82?=
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---
 .../core/query/NegativeQueryColumn.java       | 40 +++++++++++++++++++
 .../mybatisflex/core/query/QueryMethods.java  |  7 ++++
 2 files changed, 47 insertions(+)
 create mode 100644 mybatis-flex-core/src/main/java/com/mybatisflex/core/query/NegativeQueryColumn.java

diff --git a/mybatis-flex-core/src/main/java/com/mybatisflex/core/query/NegativeQueryColumn.java b/mybatis-flex-core/src/main/java/com/mybatisflex/core/query/NegativeQueryColumn.java
new file mode 100644
index 00000000..729a8849
--- /dev/null
+++ b/mybatis-flex-core/src/main/java/com/mybatisflex/core/query/NegativeQueryColumn.java
@@ -0,0 +1,40 @@
+package com.mybatisflex.core.query;
+
+import com.mybatisflex.core.FlexConsts;
+import com.mybatisflex.core.dialect.IDialect;
+
+import java.util.List;
+
+/**
+ * 取相反数（{@code -column}）。
+ *
+ * @author 王帅
+ * @since 2023-11-09
+ */
+public class NegativeQueryColumn extends QueryColumn implements HasParamsColumn {
+
+    private final QueryColumn queryColumn;
+
+    public NegativeQueryColumn(QueryColumn queryColumn) {
+        this.queryColumn = queryColumn;
+    }
+
+    @Override
+    public Object[] getParamValues() {
+        if (queryColumn instanceof HasParamsColumn) {
+            return ((HasParamsColumn) queryColumn).getParamValues();
+        }
+        return FlexConsts.EMPTY_ARRAY;
+    }
+
+    @Override
+    String toSelectSql(List<QueryTable> queryTables, IDialect dialect) {
+        return toConditionSql(queryTables, dialect) + WrapperUtil.buildColumnAlias(alias, dialect);
+    }
+
+    @Override
+    String toConditionSql(List<QueryTable> queryTables, IDialect dialect) {
+        return "-" + queryColumn.toConditionSql(queryTables, dialect);
+    }
+
+}
diff --git a/mybatis-flex-core/src/main/java/com/mybatisflex/core/query/QueryMethods.java b/mybatis-flex-core/src/main/java/com/mybatisflex/core/query/QueryMethods.java
index a51d20ee..768c6f83 100644
--- a/mybatis-flex-core/src/main/java/com/mybatisflex/core/query/QueryMethods.java
+++ b/mybatis-flex-core/src/main/java/com/mybatisflex/core/query/QueryMethods.java
@@ -2408,6 +2408,13 @@ public class QueryMethods {
         return new RawQueryColumn("'" + s + "'");
     }
 
+    /**
+     * 构建相反数。
+     */
+    public static QueryColumn negative(QueryColumn queryColumn) {
+        return new NegativeQueryColumn(queryColumn);
+    }
+
     /**
      * 构建自定义列。
      */