PostgreSQL 的 语法分析的理解(七)

把target_list 中的这一段改变一下：

| a_expr IDENT                    
    {                
        $$ = makeNode(ResTarget);            
        $$->name = $2;            
        $$->indirection = NIL;            
        $$->val = (Node *)$1;            
        $$->location = @1;            
    }                

变成：

| a_expr IDENT                    
    {                
        $$ = makeNode(ResTarget);            
        $$->name = $2;            
        $$->indirection = NIL;            
        $$->val = (Node *)$1;            
        $$->location = @1; 
        fprintf(stderr,"target_list,IDENT,%s\n",$2);        
    }                

psql执行：select id myid from a6;

后台出现：target_list, IDENT,myid