1. 实现配置文件解析

2. 实现数据库连接

vendor/gorm.io/gorm/callbacks/helper.go

@@ -0,0 +1,152 @@
+package callbacks
+
+import (
+	"reflect"
+	"sort"
+
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+)
+
+// ConvertMapToValuesForCreate convert map to values
+func ConvertMapToValuesForCreate(stmt *gorm.Statement, mapValue map[string]interface{}) (values clause.Values) {
+	values.Columns = make([]clause.Column, 0, len(mapValue))
+	selectColumns, restricted := stmt.SelectAndOmitColumns(true, false)
+
+	keys := make([]string, 0, len(mapValue))
+	for k := range mapValue {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	for _, k := range keys {
+		value := mapValue[k]
+		if stmt.Schema != nil {
+			if field := stmt.Schema.LookUpField(k); field != nil {
+				k = field.DBName
+			}
+		}
+
+		if v, ok := selectColumns[k]; (ok && v) || (!ok && !restricted) {
+			values.Columns = append(values.Columns, clause.Column{Name: k})
+			if len(values.Values) == 0 {
+				values.Values = [][]interface{}{{}}
+			}
+
+			values.Values[0] = append(values.Values[0], value)
+		}
+	}
+	return
+}
+
+// ConvertSliceOfMapToValuesForCreate convert slice of map to values
+func ConvertSliceOfMapToValuesForCreate(stmt *gorm.Statement, mapValues []map[string]interface{}) (values clause.Values) {
+	columns := make([]string, 0, len(mapValues))
+
+	// when the length of mapValues is zero,return directly here
+	// no need to call stmt.SelectAndOmitColumns method
+	if len(mapValues) == 0 {
+		stmt.AddError(gorm.ErrEmptySlice)
+		return
+	}
+
+	var (
+		result                    = make(map[string][]interface{}, len(mapValues))
+		selectColumns, restricted = stmt.SelectAndOmitColumns(true, false)
+	)
+
+	for idx, mapValue := range mapValues {
+		for k, v := range mapValue {
+			if stmt.Schema != nil {
+				if field := stmt.Schema.LookUpField(k); field != nil {
+					k = field.DBName
+				}
+			}
+
+			if _, ok := result[k]; !ok {
+				if v, ok := selectColumns[k]; (ok && v) || (!ok && !restricted) {
+					result[k] = make([]interface{}, len(mapValues))
+					columns = append(columns, k)
+				} else {
+					continue
+				}
+			}
+
+			result[k][idx] = v
+		}
+	}
+
+	sort.Strings(columns)
+	values.Values = make([][]interface{}, len(mapValues))
+	values.Columns = make([]clause.Column, len(columns))
+	for idx, column := range columns {
+		values.Columns[idx] = clause.Column{Name: column}
+
+		for i, v := range result[column] {
+			if len(values.Values[i]) == 0 {
+				values.Values[i] = make([]interface{}, len(columns))
+			}
+
+			values.Values[i][idx] = v
+		}
+	}
+	return
+}
+
+func hasReturning(tx *gorm.DB, supportReturning bool) (bool, gorm.ScanMode) {
+	if supportReturning {
+		if c, ok := tx.Statement.Clauses["RETURNING"]; ok {
+			returning, _ := c.Expression.(clause.Returning)
+			if len(returning.Columns) == 0 || (len(returning.Columns) == 1 && returning.Columns[0].Name == "*") {
+				return true, 0
+			}
+			return true, gorm.ScanUpdate
+		}
+	}
+	return false, 0
+}
+
+func checkMissingWhereConditions(db *gorm.DB) {
+	if !db.AllowGlobalUpdate && db.Error == nil {
+		where, withCondition := db.Statement.Clauses["WHERE"]
+		if withCondition {
+			if _, withSoftDelete := db.Statement.Clauses["soft_delete_enabled"]; withSoftDelete {
+				whereClause, _ := where.Expression.(clause.Where)
+				withCondition = len(whereClause.Exprs) > 1
+			}
+		}
+		if !withCondition {
+			db.AddError(gorm.ErrMissingWhereClause)
+		}
+		return
+	}
+}
+
+type visitMap = map[reflect.Value]bool
+
+// Check if circular values, return true if loaded
+func loadOrStoreVisitMap(visitMap *visitMap, v reflect.Value) (loaded bool) {
+	if v.Kind() == reflect.Ptr {
+		v = v.Elem()
+	}
+
+	switch v.Kind() {
+	case reflect.Slice, reflect.Array:
+		loaded = true
+		for i := 0; i < v.Len(); i++ {
+			if !loadOrStoreVisitMap(visitMap, v.Index(i)) {
+				loaded = false
+			}
+		}
+	case reflect.Struct, reflect.Interface:
+		if v.CanAddr() {
+			p := v.Addr()
+			if _, ok := (*visitMap)[p]; ok {
+				return true
+			}
+			(*visitMap)[p] = true
+		}
+	}
+
+	return
+}