fix(db): 修复表列标识符处理逻辑确保聚合函数正常工作

- 修改 ProcessColumn 方法，table.column 格式不再添加反引号，只添加前缀
- 修改 ProcessColumnNoPrefix 方法，table.column 格式不加引号保持原始格式
- 更新 ProcessConditionString 方法，条件字符串中的 table.column 不加反引号
- 修复聚合函数如 Sum、Avg、Max、Min 在 table.column 格式下的正确性
- 添加完整的 table.column 格式测试用例验证功能一致性
- 确保返回的列名与原始列名一致，便于聚合函数等场景读取结果

db/identifier.go

@@ -83,21 +83,22 @@ func (p *IdentifierProcessor) ProcessTableNameNoPrefix(name string) string {
 
 // ProcessColumn 处理 table.column 格式
 // 输入: "name" 或 "order.name" 或 "`order`.name" 或 "`order`.`name`"
-// 输出: "`name`" 或 "`app_order`.`name`" (MySQL)
+// 输出: "`name`" 或 "app_order.name"
+// 注意: 单独的列名加引号（避免关键字冲突），table.column 格式不加引号
 func (p *IdentifierProcessor) ProcessColumn(name string) string {
 	// 检查是否包含点号
 	if !strings.Contains(name, ".") {
-		// 单独的列名，只加引号
+		// 单独的列名，需要加引号（避免关键字冲突）
 		return p.dialect.QuoteIdentifier(p.stripQuotes(name))
 	}
 
-	// 处理 table.column 格式
+	// 处理 table.column 格式，不加引号，只添加前缀
 	parts := p.splitTableColumn(name)
 	if len(parts) == 2 {
 		tableName := p.stripQuotes(parts[0])
 		columnName := p.stripQuotes(parts[1])
-		// 表名添加前缀
+		// table.column 格式不加反引号
-		return p.dialect.QuoteIdentifier(p.prefix+tableName) + "." + p.dialect.QuoteIdentifier(columnName)
+		return p.prefix + tableName + "." + columnName
 	}
 
 	// 无法解析，返回原样但转换引号
@@ -107,14 +108,16 @@ func (p *IdentifierProcessor) ProcessColumn(name string) string {
 // ProcessColumnNoPrefix 处理 table.column 格式（不添加前缀）
 func (p *IdentifierProcessor) ProcessColumnNoPrefix(name string) string {
 	if !strings.Contains(name, ".") {
+		// 单独的列名，需要加引号（避免关键字冲突）
 		return p.dialect.QuoteIdentifier(p.stripQuotes(name))
 	}
 
+	// table.column 格式不加引号
 	parts := p.splitTableColumn(name)
 	if len(parts) == 2 {
 		tableName := p.stripQuotes(parts[0])
 		columnName := p.stripQuotes(parts[1])
-		return p.dialect.QuoteIdentifier(tableName) + "." + p.dialect.QuoteIdentifier(columnName)
+		return tableName + "." + columnName
 	}
 
 	return p.convertQuotes(name)
@@ -122,7 +125,9 @@ func (p *IdentifierProcessor) ProcessColumnNoPrefix(name string) string {
 
 // ProcessConditionString 智能解析条件字符串（如 ON 条件）
 // 输入: "user.id = order.user_id AND order.status = 1"
-// 输出: "`app_user`.`id` = `app_order`.`user_id` AND `app_order`.`status` = 1" (MySQL)
+// 输出: "app_user.id = app_order.user_id AND app_order.status = 1"
+// 注意: table.column 格式不加反引号，因为 MySQL/SQLite/PostgreSQL 都能正确解析
+// 这样可以保持返回的列名与原始列名一致，便于聚合函数等场景读取结果
 func (p *IdentifierProcessor) ProcessConditionString(condition string) string {
 	if condition == "" {
 		return condition
@@ -131,20 +136,21 @@ func (p *IdentifierProcessor) ProcessConditionString(condition string) string {
 	result := condition
 
 	// 首先处理已有完整引号的情况 `table`.`column` 或 "table"."column"
-	// 这些需要先处理，因为它们的格式最明确
+	// 去除引号，只添加前缀
 	fullyQuotedPattern := regexp.MustCompile("[`\"]([a-zA-Z_][a-zA-Z0-9_]*)[`\"]\\.[`\"]([a-zA-Z_][a-zA-Z0-9_]*)[`\"]")
 	result = fullyQuotedPattern.ReplaceAllStringFunc(result, func(match string) string {
 		parts := fullyQuotedPattern.FindStringSubmatch(match)
 		if len(parts) == 3 {
 			tableName := parts[1]
 			colName := parts[2]
-			return p.dialect.QuoteIdentifier(p.prefix+tableName) + "." + p.dialect.QuoteIdentifier(colName)
+			// table.column 格式不加反引号，只添加前缀
+			return p.prefix + tableName + "." + colName
 		}
 		return match
 	})
 
 	// 然后处理部分引号的情况 `table`.column 或 "table".column
-	// 注意：需要避免匹配已处理的内容（已经是双引号包裹的）
+	// 去除引号，只添加前缀
 	quotedTablePattern := regexp.MustCompile("[`\"]([a-zA-Z_][a-zA-Z0-9_]*)[`\"]\\.([a-zA-Z_][a-zA-Z0-9_]*)(?:[^`\"]|$)")
 	result = quotedTablePattern.ReplaceAllStringFunc(result, func(match string) string {
 		parts := quotedTablePattern.FindStringSubmatch(match)
@@ -159,7 +165,8 @@ func (p *IdentifierProcessor) ProcessConditionString(condition string) string {
 					suffix = string(lastChar)
 				}
 			}
-			return p.dialect.QuoteIdentifier(p.prefix+tableName) + "." + p.dialect.QuoteIdentifier(colName) + suffix
+			// table.column 格式不加反引号，只添加前缀
+			return p.prefix + tableName + "." + colName + suffix
 		}
 		return match
 	})
@@ -174,7 +181,8 @@ func (p *IdentifierProcessor) ProcessConditionString(condition string) string {
 			tableName := parts[2]
 			colName := parts[3]
 			suffix := parts[4] // 后面的边界字符
-			return prefix + p.dialect.QuoteIdentifier(p.prefix+tableName) + "." + p.dialect.QuoteIdentifier(colName) + suffix
+			// table.column 格式不加反引号，只添加前缀
+			return prefix + p.prefix + tableName + "." + colName + suffix
 		}
 		return match
 	})

example/main.go

@@ -564,32 +564,36 @@ func testAggregate(that *Context) Map {
 	test2["count"] = count2
 	tests = append(tests, test2)
 
-	// 5.3 Sum 求和
+	// 5.3 Sum 求和 - 单字段名
-	test3 := Map{"name": "Sum 求和"}
+	test3 := Map{"name": "Sum 求和 (单字段名)"}
 	sum3 := that.Db.Sum("article", "click_num", Map{"state": 0})
 	test3["result"] = sum3 >= 0
 	test3["sum"] = sum3
+	test3["lastQuery"] = that.Db.LastQuery
 	tests = append(tests, test3)
 
-	// 5.4 Avg 平均值
+	// 5.4 Avg 平均值 - 单字段名
-	test4 := Map{"name": "Avg 平均值"}
+	test4 := Map{"name": "Avg 平均值 (单字段名)"}
 	avg4 := that.Db.Avg("article", "click_num", Map{"state": 0})
 	test4["result"] = avg4 >= 0
 	test4["avg"] = avg4
+	test4["lastQuery"] = that.Db.LastQuery
 	tests = append(tests, test4)
 
-	// 5.5 Max 最大值
+	// 5.5 Max 最大值 - 单字段名
-	test5 := Map{"name": "Max 最大值"}
+	test5 := Map{"name": "Max 最大值 (单字段名)"}
 	max5 := that.Db.Max("article", "click_num", Map{"state": 0})
 	test5["result"] = max5 >= 0
 	test5["max"] = max5
+	test5["lastQuery"] = that.Db.LastQuery
 	tests = append(tests, test5)
 
-	// 5.6 Min 最小值
+	// 5.6 Min 最小值 - 单字段名
-	test6 := Map{"name": "Min 最小值"}
+	test6 := Map{"name": "Min 最小值 (单字段名)"}
 	min6 := that.Db.Min("article", "sort", Map{"state": 0})
 	test6["result"] = true // sort 可能为 0
 	test6["min"] = min6
+	test6["lastQuery"] = that.Db.LastQuery
 	tests = append(tests, test6)
 
 	// 5.7 GROUP BY 分组统计
@@ -606,6 +610,117 @@ func testAggregate(that *Context) Map {
 	test7["stats"] = stats7
 	tests = append(tests, test7)
 
+	// ==================== 新增：table.column 格式测试 ====================
+	// 5.8 Sum 求和 - table.column 格式（修复验证）
+	test8 := Map{"name": "Sum 求和 (table.column 格式)"}
+	sum8 := that.Db.Sum("article", "article.click_num", Map{"state": 0})
+	test8["result"] = sum8 >= 0
+	test8["sum"] = sum8
+	test8["expected"] = "与单字段名 Sum 结果相同"
+	test8["match_single_field"] = sum8 == sum3 // 应该与 test3 结果相同
+	test8["lastQuery"] = that.Db.LastQuery
+	tests = append(tests, test8)
+
+	// 5.9 Avg 平均值 - table.column 格式
+	test9 := Map{"name": "Avg 平均值 (table.column 格式)"}
+	avg9 := that.Db.Avg("article", "article.click_num", Map{"state": 0})
+	test9["result"] = avg9 >= 0
+	test9["avg"] = avg9
+	test9["match_single_field"] = avg9 == avg4
+	test9["lastQuery"] = that.Db.LastQuery
+	tests = append(tests, test9)
+
+	// 5.10 Max 最大值 - table.column 格式
+	test10 := Map{"name": "Max 最大值 (table.column 格式)"}
+	max10 := that.Db.Max("article", "article.click_num", Map{"state": 0})
+	test10["result"] = max10 >= 0
+	test10["max"] = max10
+	test10["match_single_field"] = max10 == max5
+	test10["lastQuery"] = that.Db.LastQuery
+	tests = append(tests, test10)
+
+	// 5.11 Min 最小值 - table.column 格式
+	test11 := Map{"name": "Min 最小值 (table.column 格式)"}
+	min11 := that.Db.Min("article", "article.sort", Map{"state": 0})
+	test11["result"] = true
+	test11["min"] = min11
+	test11["match_single_field"] = min11 == min6
+	test11["lastQuery"] = that.Db.LastQuery
+	tests = append(tests, test11)
+
+	// ==================== 带 JOIN 的聚合函数测试 ====================
+	// 5.12 Sum 带 JOIN - table.column 格式
+	test12 := Map{"name": "Sum 带 JOIN (table.column 格式)"}
+	joinSlice := Slice{
+		Map{"[>]ctg": "article.ctg_id = ctg.id"},
+	}
+	sum12 := that.Db.Sum("article", "article.click_num", joinSlice, Map{"article.state": 0})
+	test12["result"] = sum12 >= 0
+	test12["sum"] = sum12
+	test12["lastQuery"] = that.Db.LastQuery
+	tests = append(tests, test12)
+
+	// 5.13 Count 带 JOIN
+	test13 := Map{"name": "Count 带 JOIN"}
+	count13 := that.Db.Count("article", joinSlice, Map{"article.state": 0})
+	test13["result"] = count13 >= 0
+	test13["count"] = count13
+	test13["lastQuery"] = that.Db.LastQuery
+	tests = append(tests, test13)
+
+	// ==================== Select 方法验证 table.column 格式 ====================
+	// 5.14 Select 使用 table.column 选择字段
+	test14 := Map{"name": "Select table.column 字段选择"}
+	articles14 := that.Db.Select("article",
+		"article.id, article.title, article.click_num",
+		Map{"article.state": 0, "LIMIT": 3})
+	test14["result"] = len(articles14) >= 0
+	test14["count"] = len(articles14)
+	// 验证返回的 Map 中字段名是否正确（不带反引号）
+	if len(articles14) > 0 {
+		keys := []string{}
+		for k := range articles14[0] {
+			keys = append(keys, k)
+		}
+		test14["returned_keys"] = keys
+		// 检查是否能正确读取值（字段名是 article.id 还是 id）
+		test14["sample_data"] = articles14[0]
+	}
+	test14["lastQuery"] = that.Db.LastQuery
+	tests = append(tests, test14)
+
+	// 5.15 Select 带 JOIN 使用 table.column
+	test15 := Map{"name": "Select 带 JOIN table.column"}
+	articles15 := that.Db.Select("article",
+		joinSlice,
+		"article.id, article.title, ctg.name as ctg_name",
+		Map{"article.state": 0, "LIMIT": 3})
+	test15["result"] = len(articles15) >= 0
+	test15["count"] = len(articles15)
+	if len(articles15) > 0 {
+		keys := []string{}
+		for k := range articles15[0] {
+			keys = append(keys, k)
+		}
+		test15["returned_keys"] = keys
+		test15["sample_data"] = articles15[0]
+	}
+	test15["lastQuery"] = that.Db.LastQuery
+	tests = append(tests, test15)
+
+	// ==================== 聚合函数结果对比验证 ====================
+	// 5.16 验证 table.column 与单字段结果一致性
+	test16 := Map{"name": "聚合函数一致性验证"}
+	allMatch := (sum8 == sum3) && (avg9 == avg4) && (max10 == max5) && (min11 == min6)
+	test16["result"] = allMatch
+	test16["sum_match"] = sum8 == sum3
+	test16["avg_match"] = avg9 == avg4
+	test16["max_match"] = max10 == max5
+	test16["min_match"] = min11 == min6
+	test16["summary"] = fmt.Sprintf("Sum: %v=%v, Avg: %v=%v, Max: %v=%v, Min: %v=%v",
+		sum3, sum8, avg4, avg9, max5, max10, min6, min11)
+	tests = append(tests, test16)
+
 	result["tests"] = tests
 	result["success"] = true
 	return result