diff --git a/Src/Asp.Net/SqlSugar/ExpressionsToSql/Subquery/Items/SubTop.cs b/Src/Asp.Net/SqlSugar/ExpressionsToSql/Subquery/Items/SubTop.cs
index 8025ea004..6a5f2d181 100644
--- a/Src/Asp.Net/SqlSugar/ExpressionsToSql/Subquery/Items/SubTop.cs
+++ b/Src/Asp.Net/SqlSugar/ExpressionsToSql/Subquery/Items/SubTop.cs
@@ -61,6 +61,10 @@ namespace SqlSugar
             {
                 return (HasWhere?"AND":"WHERE")+ " ROWNUM=1";
             }
+            else if (this.Context is PostgreSQLExpressionContext)
+            {
+                return "limit 1";
+            }
             else if (this.Context.GetLimit()!=null)
             {
                 return this.Context.GetLimit();
diff --git a/Src/Asp.NetCore2/SqlSugar/ExpressionsToSql/Subquery/Items/SubTop.cs b/Src/Asp.NetCore2/SqlSugar/ExpressionsToSql/Subquery/Items/SubTop.cs
index 8025ea004..6a5f2d181 100644
--- a/Src/Asp.NetCore2/SqlSugar/ExpressionsToSql/Subquery/Items/SubTop.cs
+++ b/Src/Asp.NetCore2/SqlSugar/ExpressionsToSql/Subquery/Items/SubTop.cs
@@ -61,6 +61,10 @@ namespace SqlSugar
             {
                 return (HasWhere?"AND":"WHERE")+ " ROWNUM=1";
             }
+            else if (this.Context is PostgreSQLExpressionContext)
+            {
+                return "limit 1";
+            }
             else if (this.Context.GetLimit()!=null)
             {
                 return this.Context.GetLimit();