support sqlite3

builder/aggregation.go

@@ -0,0 +1,66 @@
+package builder
+
+import "github.com/tangpanqing/aorm/null"
+
+type IntStruct struct {
+	C null.Int
+}
+
+type FloatStruct struct {
+	C null.Float
+}
+
+// Count 聚合函数-数量
+func (ex *Builder) Count(fieldName string) (int64, error) {
+	var obj []IntStruct
+	err := ex.SelectCount(fieldName, "c").GetMany(&obj)
+	if err != nil {
+		return 0, err
+	}
+
+	return obj[0].C.Int64, nil
+}
+
+// Sum 聚合函数-合计
+func (ex *Builder) Sum(fieldName string) (float64, error) {
+	var obj []FloatStruct
+	err := ex.SelectSum(fieldName, "c").GetMany(&obj)
+	if err != nil {
+		return 0, err
+	}
+
+	return obj[0].C.Float64, nil
+}
+
+// Avg 聚合函数-平均值
+func (ex *Builder) Avg(fieldName string) (float64, error) {
+	var obj []FloatStruct
+	err := ex.SelectAvg(fieldName, "c").GetMany(&obj)
+	if err != nil {
+		return 0, err
+	}
+
+	return obj[0].C.Float64, nil
+}
+
+// Max 聚合函数-最大值
+func (ex *Builder) Max(fieldName string) (float64, error) {
+	var obj []FloatStruct
+	err := ex.SelectMax(fieldName, "c").GetMany(&obj)
+	if err != nil {
+		return 0, err
+	}
+
+	return obj[0].C.Float64, nil
+}
+
+// Min 聚合函数-最小值
+func (ex *Builder) Min(fieldName string) (float64, error) {
+	var obj []FloatStruct
+	err := ex.SelectMin(fieldName, "c").GetMany(&obj)
+	if err != nil {
+		return 0, err
+	}
+
+	return obj[0].C.Float64, nil
+}