Fix lastval in PostgresCompiler for SqlKata.Execution

Author: tlaguz

QueryBuilder/Compilers/PostgresCompiler.cs

@@ -4,7 +4,7 @@ public class PostgresCompiler : Compiler
     {
         public PostgresCompiler()
         {
-            LastId = "SELECT lastval()";
+            LastId = "SELECT lastval() AS id";
         }
 
         public override string EngineCode { get; } = EngineCodes.PostgreSql;
@@ -38,4 +38,4 @@ protected override string CompileBasicDateCondition(SqlResult ctx, BasicDateCond
             return sql;
         }
     }
-}
+}