fix: pg,mssql dual表需要一条数据

sql/tools/convertor.py

@@ -207,7 +207,6 @@ class Convertor(ABC):
 -- Table structure for dual
 -- ----------------------------
 {dual}
-
 """
             )
 
@@ -371,7 +370,17 @@ CREATE SEQUENCE {table_name}_seq
         return """DROP TABLE IF EXISTS dual;
 CREATE TABLE dual
 (
-);"""
+    id int2
+);
+
+COMMENT ON TABLE dual IS '数据库连接的表';
+
+-- ----------------------------
+-- Records of dual
+-- ----------------------------
+-- @formatter:off
+INSERT INTO dual VALUES (1);
+-- @formatter:on"""
 
 
 class OracleConvertor(Convertor):
@@ -636,7 +645,7 @@ GO
 
 CREATE TABLE dual
 (
-  id int NULL
+  id int
 )
 GO
 
@@ -644,7 +653,15 @@ EXEC sp_addextendedproperty
     'MS_Description', N'数据库连接的表',
     'SCHEMA', N'dbo',
     'TABLE', N'dual'
-GO"""
+GO
+
+-- ----------------------------
+-- Records of dual
+-- ----------------------------
+-- @formatter:off
+INSERT INTO dual VALUES (1)
+GO
+-- @formatter:on"""
 
 
 class DM8Convertor(Convertor):