refactor: 数据库meta使用注册方式，方便可插拔

server/internal/db/dbm/postgres/dialect.go

@@ -222,6 +222,10 @@ func (md *PgsqlDialect) BatchInsert(tx *sql.Tx, tableName string, columns []stri
 	return md.dc.TxExec(tx, sqlStr, args...)
 }
 
+func (md *PgsqlDialect) GetDataConverter() dbi.DataConverter {
+	return new(DataConverter)
+}
+
 var (
 	// 数字类型
 	numberRegexp = regexp.MustCompile(`(?i)int|double|float|number|decimal|byte|bit`)
@@ -236,10 +240,6 @@ var (
 type DataConverter struct {
 }
 
-func (md *PgsqlDialect) GetDataConverter() dbi.DataConverter {
-	return new(DataConverter)
-}
-
 func (dc *DataConverter) GetDataType(dbColumnType string) dbi.DataType {
 	if numberRegexp.MatchString(dbColumnType) {
 		return dbi.DataTypeNumber

server/internal/db/dbm/postgres/meta.go

@@ -9,22 +9,13 @@ import (
 	"mayfly-go/pkg/utils/netx"
 	"net"
 	"strings"
-	"sync"
 	"time"
 
 	pq "gitee.com/liuzongyang/libpq"
 )
 
-var (
-	meta dbi.Meta
-	once sync.Once
-)
-
-func GetMeta() dbi.Meta {
-	once.Do(func() {
-		meta = new(PostgresMeta)
-	})
-	return meta
+func init() {
+	dbi.Register(dbi.DbTypePostgres, new(PostgresMeta))
 }
 
 type PostgresMeta struct {